Why does my GMC Sierra 1500 run rough at idle?

The spray smoothing out the rough rpm is an indication of the engine running lean, could be low fuel pressure, could be a vacuum leak. With it running rough at an idle and smoothing out at a higher rpm is a general sign of a vacuum leak.

Why does my Chevy Truck start and idle?

Not sure why this test caused a better and longer gas flow than the above test of just putting the ignition in the ON position and seeing how much gas comes out of the line before the fuel filter. Last test says to start the vehicle and remove the relay.

What does the fuel smell like in a GMC Sierra 1500?

If so pull the air filter off and sniff the throttle body for a fuel smell. If the diaphragm has ruptured it will literally be like putting a hose with fuel into the intake and running it full.

What kind of engine does a 1995 GMC have?

I have a 1995 GMC that I have owned since new. It has 212,000 miles on it, a 305 TBI, and a manual five speed. It started running bad all at once. It idles rough, at different speeds and never settles down, (between 900 and 1300 rpm. It smells like raw gas, smokes, and has no power to get started from a stop.

Why is my GMC Sierra 1500 stalling and dying?

There is no code given. Have changed the injectors, timing, fuel tank, fuel pump, fuel pump, map sensor, cooling temp sensor on front of block, rebuilt the tbi, air idea valve. None of this hasite helped. The truck starts and dies. Have to give a little gas to keep running. While driving have to 2 foot it so it won’t die.

Why does my Chevy Silverado idle and stall when stopping?

I had a trouble code of # 22 t.p.s, I replaced the throttle position sensor, m.a.p sensor, and the idle air control sensor,however i am still having the problem, it is throttle body injected, and there arent any other codes showing up. Any help would be much appreciated. Hello Clay.

What to do when your car stalls at idle?

Use a good safe cleaner and wipe the throttle body all inside as much as you can and open the throttle and clean as deep as you can and then while running a bit faster than idle spray cleaner into the other holes you may see where air will bypass the throttle plate. I believe this will cure your problem of stalling at idle.

What makes a Chevy 5.7 TBI run rough?

If you have the throttle just barely open it will smooth out until it upshifts then it does it again until the rpms build. If I push in the throttle even 1/8th of the way in it just sputters and runs like crap.

What causes a GMC Sierra 1500 to lean?

The only other thing that will cause a lean condition is low fuel pressure. A vacuum leak will be problematic at idle and go away with higher rpms. Low fuel pressure will get much worse at higher rpms. 123 people found this helpful.

Why does my car engine run rough while idling?

When your car engine runs as it should, everything should be smooth without any noise. When any number of things goes wrong, the engine can start running rough, especially while idling. By understanding the causes of a car engine that has a rough idle, you can resolve the issue easily.

Why is my GMC Sierra 1500 stalling out?

No change. Next, read somewhere that bad ground wire on Thermostat housing can cause ECM issues. Checked it, cleaned it off, verfied that contact wanhers are all steel and attract a magnet, reinstall the ground wire.

What causes the engine to start ticking at idle?

2. Exhaust Manifold Leak. An exhaust manifold leak is the cause of engine ticking at idle and acceleration. It happens when exhaust gases leak at high pressure from a leak in the gasket or a rupture in the manifold. This is not a serious problem, and you can still drive.

Why is my Silverado Sierra sluggish to accelerate?

Have a KN intake system on it and keep it clean so I dont think that is it but I havent really done anything else as far as modifications. After accelerating it feels like it starts to let loose and eventually seems to get up to speed. Any ideas of what I can do? Get a custom tune. I would get an exhaust of some sort to help with the tune.

Why does my Vortec 5300 feel sluggish when I accelerate?

I have noticed that when I accelerate it feels a bit sluggish. Have a KN intake system on it and keep it clean so I dont think that is it but I havent really done anything else as far as modifications. After accelerating it feels like it starts to let loose and eventually seems to get up to speed.

What was the problem with my GMC Sierra 1500?

Did have one cracked vacume line from the throttle body to the purge solenoid, also replaced. Seems to have plenty of vacume through out the system. Removed and inspected the egr valve, no excessive carbon build up and appears to be working properly, good vacume going into the solenoid, replaced the solenoid just for good measure.

What’s the problem with my Silverado 4.3 V6?

2007 Silverado 4.3 V6 -39,000 miles…no engine or tranny mods. No exhaust. I do have a K&N air filter that I just cleaned. I don’t think I have that MAF sensor on my intake like the more expensive trucks do. My problem seems to be a lack of power, like it just doesn’t want to go (V6 jokes aside).

Why does my GM V8 engine misfire when cold?

Because, GM V8 engines are very prone to a rough idle and engine misfire when cold. The check engine light may also come on, with codes P0300, P0171 and PO174. But, as the engine warms up, the engine misfire or rough idle tends to go away; which seems confusing.

Why is my GM 4.8l engine running too lean?

The engine may be running too lean, due to a leaking intake manifold. Too lean means too much air and not enough fuel; according to the power control module (PCM) calculation. When the engine is cold, not all sensors function. As the engine warms up the oxygen sensors report the lean condition.

How long does a Chevy 4.3L Vortec engine last?

3 vortec is a very strong and reliable motor, proven by it being the longest lasting production vortec engine. Generally, these engines are extremely capable of lasting up to 300,000 miles.

Why is my Chevy Vortec 4300 V6 leaking fuel?

In the L35 and LF6 engines, the spider injectors are known to leak at the pressure regulator and at the supply and return lines due to a design fault. Outside of leaking fuel onto the exterior of the engine itself, it can cause excess fuel to get sucked into the engine.

What causes engine knock on a 4.3L Vortec?

Engine knock can be caused by a ton of factors, such as low-grade fuel, bad spark plugs, carbon build-up, etc. Engine knock is terrible for your engines internals and can cause serious damage to the pistons and to the cylinder walls. On the 4.3L vortec, the cause of the engine knock has not necessarily been figured out, still to this day.

Why is my idle control not working on my car?

If the idle has not changed at all, it’s likely because your idle control motor has not been functioning. If the idle control motor was working, disconnecting it should have created a difference in the engine’s idle. This test confirms there’s an issue with the idle control motor, but not what the issue may be.

Is there a problem with my Sonoma V6?

Ok, I have V6 in my 2000gmc sonoma that will not crank when attempting to start. The dash lights up, under the dash clicks (normal sounds) are there, under the fuse box relays click as well but no sound at all coming from solenoid or starter.

Why is my Sonoma S15 not starting properly?

No warnings, like sputtering, or misfiring sounds, just suddenly wasn’t there. From that he was now pretty sure it was the trucks computer, and when I told him that the first time we did a engine diagnostic the fuse that let the computers talk was missing, he became certain that it was the computer.

Why does my 1994 Chevy S-10 not start?

1994 Chevrolet S-10 4.3 tbi. I never get the signal to turn on the fuel pump or fire the injectors but if i poor gas in the intake once the truck starts it runs fine. Any ideas ? I have replaced the fuel pump relay oil pressure switch and computer.

Can a bad fuel pump start a truck?

Yes and have nothing. Well getting to start by adding fuel to the throttle body is not going to turn on some special switch that will send a signal to the pump and injectors. I’m sure you probably just have a bad fuel pump that doesn’t have enough pressure or volume to start the truck, but at running speed can keep up.

How to troubleshoot an automotive engine high idle?

The troubleshooting procedure for high and low idle conditions are similar, which are included in the following: Step 1 – If the check engine or service engine light soon has illuminated retrieving the diagnostic trouble codes could lead you in the right direction of what the problem is, or is related too.

What to do when your engine RPM drops?

Engine have fuel problem . Somewhere the fuel drop then suddenly rpm decrease better check the complete fuel system from tank to injectors also check the rpm sensor . Was this answer helpful? check fuel pressure between fuel pump and injectors. you may have a fuel pump that is about to fail.

How often does the engine idle during a drive?

• The learned idling air flow volume remains at the maximum or minimum volume five times or more during a drive cycle. • After driving at 6.25 mph or more, the actual engine idling speed varies from the target idling speed by between 100 and 200 rpm, five times or more during a drive cycle.

Why is my car idling at high RPM?

One very common cause of idling rough is a problem with a vacuum hose in the vehicle. The hose could be damaged, loose, or worn out, creating a leak. This could result in an abundance of air mixing with the gasoline, which would result in a misfire. Then, the result of that would be a car that is idling rough or having a higher than normal RPM.

Is it normal to have a rough idle?

This is definitely not a normal situation. If you are experiencing a rough idle or your RPM is running high, then there are a variety of reasons for why this could be happening. It is not always easy to diagnose the cause because there are so many factors involved here. Below are the top 5 causes that a mechanic would look for.

What’s the difference between high idle and low idle?

Step by step automotive repair guide on how to troubleshoot and fix an engine that is idling high (fast) or low (slow). (Note: The engine idle speed is controlled by the computer and is NOT adjustable.)

Why does my vacuum have a rough idle?

Leaks in these hoses and in other parts of the vacuum system can be another cause of a rough idle, often because of a lean air-fuel mixture from excess air entering the system.

When does a car have a rough idle?

November 27, 2017. It’s easy to tell when your car has a rough idle: When you start the engine, it won’t run at a steady rate. It may almost stall, or it may run at varying RPMs without your putting your foot on the gas, or it may do both.

What should the RPM be on an idling car?

When you start your engine, and just let it run without pressing on the accelerator or putting it into gear, that’s idling. A properly idling engine should be able to maintain a steady but low rate of revolutions, somewhere in the vicinity of 1,000 RPM.

Why does my Dodge Dakota have a rough idle?

What are common reasons my Dodge Dakota has a rough idle? While there are a variety of reasons your Dodge Dakota has a rough idle, the most common 3 are a vacuum leak, an issue with the spark plugs, or a problem with the ignition coil. See what others are asking about their Dodge Dakota.

Why does my 94 Dodge Dakota keep dying?

My 94 dodge Dakota does the same thing, it dies randomly when I am driving, completely shuts off. It also dies if I start it and let it sit for too long. I replaced the spark plugs but that didn’t fix anything not sure what it is at this point.

What’s the problem with my 2003 Dodge Dakota?

14 people found this helpful. 2003 dodge Dakota, I had the same problem. It was my idler not being controlled properly. Quick free fix. Unhook your battery for a about 10-20 seconds, let everything reset and he idle right again.

What kind of engine does a 1993 Dodge Dakota have?

1993 Dakota 3.9 4×2 manual. Dies occasionally also, just like ryanodhrty’s (for example coming to a red light in third so i hit the clutch and come to a complete stop and its now dead the weird part is that no lights turn off, its not like it stalls out or anything the engine just shuts down). Haven’t been able to figure it out for 3 years.

Why does my M20 engine stop at 3000 rpm?

Also, when driving uphill on the interstate, I can have the pedal all the way to the floor at 3000 RPMs and the car won’t accelerate. Sometimes in 2nd or 3rd gear between 2k and 3k RPMs, the car feels like it’s misfiring, to the point where the whole car starts bucking.

What happens to the engine when left in idling position?

When the engine is left in idling position, it maintains a steady but low rate of revolution approximately 1,000 RPM. The RPM needle stays constant, and this indicates that the vehicle’s engine is receiving the correct amount of air and fuel.

Why is my 5.3 L missing and rough idle intermittently?

5.3 L Missing and Rough Idle Intermittently I have changed Spark Plugs,Wires ,Coil Packs, and removed Fuel Injectors and soaked overnight. Engine code is a P0304. Misfire Cylinder #4. Most of the time around town is alright. When i put it on highway, it will surge like its cutting off and then pick right back up and be fine. Fuel Presure is 55 psi.

What causes an Audi A4 to idle rough?

A super lean running engine will often idle rough. The fuel injection systems job is to atomize the fuel into fine mist. If a fuel injector has an issue with this process, it will either let too much or too little fuel into the combustion chamber relative to the amount of air.

What causes rough engine idle or TDC code?

So, should the engine misfire, rough engine idle or (TDC) code; point to an air leak in the intake manifold gasket, following the below directions. A very common cause of a leaking intake manifold is the gaskets and bolts used from the factory.

What to do if your fuel injector is rough idle?

Another option is to try to clean your fuel injectors with a fuel system additive like Techron, or something similar. While an additive may or may not have much effect on your rough idle problem, you can consider this as a last-ditch effort before visiting your mechanic. Follow the directions on the product’s label.

What causes a Chevy Silverado to run rough?

If an oxygen sensor goes bad, it can make your Silverado run too lean (or rich). A super lean running engine will often idle rough. Fuel Injectors. The fuel injection systems job is to atomize the fuel into fine mist.

What can cause a tractor to lose power?

Insufficient fuel pressure to the injection pump can cause reduced power. If there is a petcock on either the top of the fuel filter housing or on the outlet of the fuel tank, make sure it’s turned fully on. On one of my tractors, it had been bumped part of the way closed and it acted exactly as you describe.

What causes a pickup truck to lose power?

You might want to check your tank for obstructions at the pickup. Something could be in there moving around, and as you use the tractor, the flow of fuel pulls it to the pickup. That may not be it, but you should at least eliminate it. Insufficient fuel pressure to the injection pump can cause reduced power.

What to do when your engine is sluggish?

What You Can Do: When you feel your engine sluggish, one of your first checks should be to inspect the spark’s strength. Use an adjustable spark tester ( Thexton is an acceptable brand) to check the spark’s health. Check at 40KV and 30KV.

What causes a car to lose power on a hill?

If the fuel pump is on its way out, it may work intermittently or not at all. A symptom of starving the car for fuel is a car that runs correctly at idle and low load, but falls flat on its face as you ask for more power (when climbing a hill, for instance). Fuel pumps may fail due to age, sediment buildup, or running the incorrect fuel.

Why do I lose power on hills GMC Sierra 1500?

2000 gmc sierra 4.3 shows lean feul but can not find how or where to look 4 people found this helpful. my 2000 sierra starts good and ideals good the only thing that shows up on the scanner is the fuel is lean everything else shows good pls help 3 people found this helpful. Bad spark control module people…….that’s the problem….

Why does my car struggle to go up hills?

Once you start experiencing low cylinder compression, your vehicle will always be struggling on an incline because the engine power won’t be strong enough to push it up there. If you start to have acceleration problems as you attempt to drive uphill, do not slam down on the gas pedal to try to get up the hill.

What to do when your car won’t idle properly?

Your engine computer notices these tiny, gradual changes and compensates for them. As a driver, you don’t notice these small changes, but they keep your vehicle idling smoothly as the miles pile up. By going back to the default settings, your engine can no longer idle properly. You have a problem. Get it diagnosed by a professional

What causes an uneven idle on an F-150?

A uneven idle on a F-150 can be a symptom of a variety of engine issues such as vacuum leaks, failed or dirty sensors or worn engine components. If the engine is older or has higher miles on it, the typical culprits will be dirty sensors and carbon deposits on engine head components.

What should the idle speed be on a 1996 F-150?

Engine running, check for leaks, nope, all looks good. On fast idle, thats Ok. Few seconds, and good, I hear it ease on down to normal idle. Playing some seeming “new” problem. When I tap the gas, 8 seconds, then eases down to normal idle of 700-800.

Is there a problem with my 1996 F-150?

Also watch a bolt hole the first go-arond. Start it up, and see what happens. Starts ok (still seemed to have that wide open throttle. Oh well, will deal with later. Engine running, check for leaks, nope, all looks good. On fast idle, thats Ok. Few seconds, and good, I hear it ease on down to normal idle. Playing some seeming “new” problem.

Why does my Ford F150 shake when I idle?

Here are the main components of the ignition system, as well as what would cause them to make your F150 shake when idling. Fouled plugs can cause a misfire, which in turn causes an idle shake. Spark Plugs – One of the absolute most common causes (if not the most common reason that your F150 may be shaking) is the spark plugs.

What happens when the diaphragm is ruptured on a GMC Sierra?

If the diaphragm has ruptured it will literally be like putting a hose with fuel into the intake and running it full. When it initially started to go it probably slowly flooded the engine to where it seemed to run ok but the excess fuel created a ton of carbon coating the O2 sensor. Since no air could pass through it, it gave a false lean reading.

What does rough idle mean on a GMC Sierra?

rough idle, stalling, loss of power. o2 sensor code 44 (lean) Replaced: coolant temp sensor, tps, map sensor, fuel filter, and o2 sensor. It will run normal on occasion but only lasts about 45 seconds or so.

Why does my GMC S15 die at high idle?

Recently my truck has began to die when coming back down to idle. In looking at the fuel injection, I can see the injectors stop injecting fuel. After it dies, it is very hard to restart unless it is left alone and cools a bit. If the IAC is unplugged, the engine will run at high idle fine.

Why does my GMC Sierra suddenly stop running?

Truck suddenly stops running, acting like it’s out of fuel. There is fuel in the gas tank and, I can hear the fuel pump when I turn the ignition on. Is there a fuse, or relay that is maybe causing this to happen?

Why is my GM Truck bogging down on hard acceleration?

If your not using delco plugs in this motor that can be a big contributor to your problem. GM vortec engines hate anything but vortec plugs and will do all kinds of weird things. And yes a clogged converter could cause this sort of thing to happen. Are the O2 codes upstream or downstream?

Why does my Ford 89 F150 stall at idle?

The idle was still solid, but it was running rich and >cutting out. >Valve not closing properly) popped up during the KOER test. I replaced >the EGR Valve and it seems to be running much smoother. But, I haven’t >had the opportunity to get it over 45 yet. One good thing is that the >acceleration. It’s not gone, but it is MUCH better.

What are the symptoms of a rough idle engine?

It is possible for you to test the EGR valve at home, using a hand held vacuum pump. Other symptoms: An EGR stuck open may include a rough idle, rough performance at low engine speeds, stalling at idle, increase in fuel consumption, fuel odors, and possibly a check engine light on. 4. MAF Sensor

What causes a car to run lean at idle?

If the root cause is an electrical problem within the idle air control valve itself, you will likely have to replace the IAC. A vacuum leak is a hole in a vehicle’s air intake system behind the mass air flow (MAF) sensor that allows unmetered air into the engine. This throws off the expected air fuel ratio and causes the vehicle to run lean.

How to troubleshoot an idle that is going up and down?

Finding the ultimate cause of an uneven idle can be a trial and error process, but a cost-effective way to cure your F-150’s idle problems is to start by cleaning specific components to see if this restores a smooth and even idle prior to replacing components.

What to do when your F-150 is going up and down?

Spray throttle body cleaner into the throttle body opening, and hold the butterfly valve open to spray the interior of the housing. Use a soft cloth to clean the throttle body after you have allowed the cleaner to work for a few minutes. Use a top-end engine cleaner to clean carbon from the engine.

What’s the idle RPM on my Chevy Suburban?

My 1997 Chevy Suburban (5.7) is acting up on me. When I start it up the RPM and idle seem fine. As I let it sit for a couple of seconds the RPM’s slowly begin to drop until they finally bottom out at about 1K. As soon as I put it into Reverse/Drive etc. the RPM’s drop below that mark and it struggles to stay running.

What should the idle rate be on a 1997 GMC Truck?

Underdog, I don’t know the 1997 5.7, but 1000rpm sounds like a high idle, not where it should “bottom out”. A V8 should idle at 500rpm. GoNDown, did you recently disconnect your battery? After I left mine dead in the yard for a while and didn’t charge it, when I started it up it ran like you describe for a few days and then it was fine.

What causes a GMC truck to lower its rpm?

To decrease RPM, the control module commands the IAC pintle to move closer to its seat, causing a lower airflow to bypass the throttle plate. A scan tool will display the control module commands to the IAC valve in counts.

What to do when your GMC Sierra stops running?

If you have fuel pressure after the above tests pull a spark plug and check for spark. If you don’t have spark check the cam position sensor in the distributor. If you have spark with no pressure it is the pump.

Why does my GMC Sierra 1500 have a rough idle?

What are common reasons my GMC Sierra 1500 has a rough idle? While there are a variety of reasons your GMC Sierra 1500 has a rough idle, the most common 3 are a vacuum leak, an issue with the spark plugs, or a problem with the ignition coil.

If so pull the air filter off and sniff the throttle body for a fuel smell. If the diaphragm has ruptured it will literally be like putting a hose with fuel into the intake and running it full.

What to do if your GMC Sierra stall out?

69 people found this helpful. I have a 98 gmc searria 4×4 i checked fuel pressure it was under i changed fuel pump and fuel filter and its still starving for fuel what to do it starts with starting fluid 42 people found this helpful.

When did the GMC Sierra have the most problems?

The model years with the most problems reported were 2004 and 2007, with more than 60 complaints each year, followed by 2002, 2003, 2005, and 2010, with more than 40 each year. Of the 112 problems, five different complaints have been reported 90 or more times.

What does Blue Smoke mean when starting an engine?

The presence of blue smoke is an indication of burning oil. Blue smoke should not be ignored but is common when starting an engine in a cold weather. The oil thins out when it is cold and some could escape into the cylinder and be burnt.

Why does my diesel engine have smoke coming from the exhaust?

Consistent smoke coming from the exhaust most likely indicates a deeper internal problem with the engine. A small puff of smoke during quick acceleration is acceptable with older diesel engines due to a lag before the turbocharger’s air flow can match the increased volume of diesel fuel injected into the cylinders.

What does it mean when your car Idles smooth?

Smooth idling indicates that your engine’s fuel and air are mixing just right. What is rough idling? If your vehicle’s idle is rough, possibly rising and falling, or having difficulty maintaining a steady rate of rotation, you may have a problem that needs fixing.

How can you tell if your car has a rough idle?

Share it! It’s easy to tell when your car has a rough idle: When you start the engine, it won’t run at a steady rate. It may almost stall, or it may run at varying RPMs without your putting your foot on the gas, or it may do both. There can be a variety of reasons why your vehicle is idling roughly.

Why does my car idle at a higher RPM than normal?

Updated January 19, 2019. If your car seems to be revved up to a higher-than-normal RPM while idling, it’s not necessarily a problem. If this problem happens while the engine is cold, it may be part of the engine’s design.

Is there an intake manifold leak at high idle?

You may have an intake manifold leak on the bottom side of the engine at the lifter galley (I base this assumption by the fact that when you spray eather into the valve cover it changes the engine speed.) Re: high idle PLEASE HELP!!! You probably have a leak like aste25 mentioned.

What’s the idle RPM on a Silverado Silverado?

Re: high idle PLEASE HELP!!! When i pull the vac line from the booster the idle rpm stays at the 1200 I had been idling for 2 yrs. It only runs rougher but maintains 1200. When I pull the same line from the back side of the intake she revs really high. Enough to scare you so I plugged it back in really fast.

Why does my car run at 1200 rpm?

Some cars, especially older cars with carburetors are designed to run at 1200 rpm or so until they are warmed up. And in modern cars, if you are running several accessories, such as the air conditioner or heater, the engine’s onboard computer may be telling it to run at a higher RPM to provide the necessary power.

Why is my GMC Sierra not moving in any gear?

It is pretty applicable to the 4L80E as well. Not Moving in any Gear – If your 2003 Sierra Transmission has a problem moving in any gear, it’s likely caused by a lack of transmission fluid. No matter how silly that sounds, and how convinced you are that it’s not the problem, go ahead and check it anyway.

What causes idle surges on a car ECM?

Idle surging can be caused due to other issues in the car, but if it happens in conjunction with other throttle position sensor symptoms, the culprit is often the TPS. At idle, the ECM will not get the correct information and the throttle will variate randomly causing idle surges.

Are there transmission problems with a 2003 GMC Sierra?

After five years, most of the issues with these trucks had been worked out. Now, these trucks are getting older, and it’s very likely that your 2003 Sierra may be having transmission problems. Below, you’ll find a ton of troubleshooting your transmission problems.

Why does my car pop when I press the throttle?

As the engine is running and you have your hand cupped over the opening, press the throttle to see if the popping gets worse, quits or smoothes the engine out. By choking the engine this way you introduce more fuel to the cylinder. The result tells us to either move on or stop and check the fine inlets for the primary fuel meter circuit.

Can a faulty intake manifold cause engine overheating?

Apart from sealing engine vacuum, certain designs will also seal engine coolant. When the intake manifold gaskets have an issue, they can cause drivability problems and even engine overheating. Usually a faulty intake manifold gasket will produce a few symptoms that can alert the driver of a potential issue. 1.

Are there any problems with the Chevy 4.3 Vortec engine?

The 4.3 Vortec engines made from 1996-2002 (L35 and LF6) have been reported to have engine knock problems. In a properly functioning engine, fuel burns in even pockets instead of all at once. The pockets burn in even timing, in sync with engine cycles. Engine knock occurs when the fuel burns unevenly and out of sync with the engine cycles.

What was the problem with my 2001 Yukon XL Denali?

I love my 2001 Yukon xl Denali with over 130,000 miles but having some starting problems. The initial problem was taking several tries to start, when after it seemed a clog was cleared and the engine banged loudly once it would clear and start and be ok for the rest of the day, but a little more difficult in colder weather.

What does low rpm mean on a GMC Truck?

Lower counts indicate that less air is commanded by the control module. This DTC is designed to detect low engine RPM that is not responding to increased IAC counts. AllOffTopic.com FTW!

How much does a GMC Yukon engine hesitate?

GMC Yukon Engine hesitates during acceleration Inspection costs $89 on average. It can be frustrating for any driver to expect certain acceleration from their vehicle only to find that the vehicle seems to be hesitant while speeding up.

How often does a GMC Yukon need to be repaired?

The other factors that contribute to GMC reliability include an average of 0.3 visits to a repair shop per year and a 17% probability of a repair being severe. There are 1,310 related questions for GMC Yukon vehicles. RepairPal’s professional community answers hundreds of questions each day.

Why does my GMC Yukon engine not start?

GMC Yukon: Engine Cranks → Won’t Start There are a lot of issues that can cause your Yukon to crank, but not start. The engine needs air, fuel, and a spark in order to run. It is highly likely that if the engine is cranking, but not starting that it has thrown an OBDII code.

How many questions are there about GMC Yukon?

There are 1,310 related questions for GMC Yukon vehicles. RepairPal’s professional community answers hundreds of questions each day. Below are the most commonly asked GMC Yukon questions.

Which is worse rough idle or perfect idle?

Very rough idle with a repetitive cycle that is smooth for a couple of seconds then misses badly, occasionally stalling. Worse problem is bad hesitation when accelerating after throttle at idle position, sometimes stalling. Worst after stationary idle, but also after moving at low to medium speed with closed throttle and then accelerating.

Why is my GMC Sierra running rough at idle?

These packs are fired by the engines computer at exactly the right time to provide the optimal ignition timing. If a coil pack goes bad, it’ll cause a misfire and rough idle condition. Really, your Sierra will be running rougher at any RPM, but a misfire will be most pronounced at idle.

What’s the problem with a ” rough idle “?

Rough idle, bad hesitation… This problem started suddenly. Very rough idle with a repetitive cycle that is smooth for a couple of seconds then misses badly, occasionally stalling. Worse problem is bad hesitation when accelerating after throttle at idle position, sometimes stalling.

What causes a car to idle rough at idle?

A clogged fuel filter stops the engine from receiving the right amount of fuel causing the engine to be rough idle. Fuel filters are often pretty cheap, and you can easily get the fuel filter removed and replaced from a nearby mechanic or do it yourself if you have some knowledge. 6. Dirty Air Filter

Why does my GMC Envoy die at idle?

Took it to them. When the vacuum line is activated for the engine, such as when the air or heat was on, the truck would die at idle (when in gear only, would not die if in neutral). I had changed the battery and on the Envoys it resets all previously stored air/ fuel, idle, etc info that the computer had previously gathered about the motor.

Why is my fuel pump not producing pressure?

The fuel pump is able to create pressure using electricity but if it is not getting the adequate voltage of electricity it will not be able to function properly. Consequently, the fuel will not be released at the perfect pressure and your car will lose efficiency.

What causes a car to run at a rough idle?

A PCV valve leak can cause the air-fuel mixture to run too lean, and this will cause a rough idle. Proper periodic servicing of the PCV valve will prevent this situation from occurring.

Leaks in these hoses and in other parts of the vacuum system can be another cause of a rough idle, often because of a lean air-fuel mixture from excess air entering the system.

What causes a car idle to be unbalanced?

Since a smooth idle depends on just the right mixture of fuel and air, there can be many possible places where that combination is getting unbalanced. Some of these causes can be simple, and some can be complicated.

What causes idle on a Great Lakes 4×4?

Take the egr valve out and see if there is a piece of carbon stuck in it. This would cause a rough idle. Also make sure the gasket is not leaking around the base of the egr valve. These would both cause the symptoms that you are experiencing.

Is the EGR valve supposed to run during idle?

However, this EGR valve isn’t supposed to operate during idle, at wide open throttle or before the engine is warmed up. If it runs at any of these times, the performance of the engine is affected.

What does it sound like when you hit 3000 rpm?

Ok so i have my car tuned up pretty well, ignition timing at about 12 degrees, brand new plugs and wires. Suddenly on my way home from town last week…i went on the gas pretty hard, and once the needle hit about 3000 RPM, it sounds like a popcorn machine in my exhaust, and the rpms jump all over the place.

When does the RPM go back to normal?

The RPM will usually go back to normal as you accelerate the vehicle, but will increase again after you stop. This is definitely not a normal situation. If you are experiencing a rough idle or your RPM is running high, then there are a variety of reasons for why this could be happening.

What causes the engine rpm to go up when idle?

When the engine idles, there will usually be a misfire that you can feel just from holding onto the steering wheel. Furthermore, the RPM of your engine will be higher than normal when the vehicle is idling. The RPM will usually go back to normal as you accelerate the vehicle, but will increase again after you stop.

What does it mean when your car is idling but not running?

When the engine is running but the vehicle is not moving, this means the engine is idling. During this time, the number of revolutions per minute (RPM) inside the engine will change.

What happens if your brake master cylinder is leaking?

If the brake master cylinder is leaking braking fluid or if there are unsecured reservoirs on the cylinder which are holding the fluid, then you will almost be guaranteed of having a low brake fluid level. This will impair your ability to slow down the vehicle.

Why does engine stall when brake is applied at idle?

If your brake pedal is stiff and it stalls when you apply the brakes, it sounds like the diaphram in you brake booster may be ruptured. Do what Steve said and pull the vacuum line to the booster and cap it off and see if it still stalls. If it doesn’t stall, then it’s time for a new booster.

What causes a GMC Sierra 1500 to have a lean idle?

Vacuum leaks can cause a lean condition and/or possibly a high idle. Check for cracked hoses a bad gasket or a faulty EGR or PCV Valve. 70 people found this helpful. The only other thing that will cause a lean condition is low fuel pressure. A vacuum leak will be problematic at idle and go away with higher rpms.

Why does my car idle with my foot on the brake?

Rough idle with foot on brake at stop light or just sitting in park in driveway runs good while driving My car has 128000 miles. My car has an automatic transmission. This may be a sign of a failing idle air control valve.

What to do if your car won’t idle?

The Fix: Set idle speed to specs. There may be some type of ignition problem. The Fix: Check and replace distributor cap, rotor, ignition wires, and spark plugs. There may be a fault in the computerized engine control system. The Fix: Bring your car to your mechanic or dealership to check the engine control system with a scan tool.

What does it mean when your car engine is idling?

Intake leak When you start the engine and let it run without pressing the pedal, it is called idling. When the engine is left in idling position, it maintains a steady but low rate of revolution approximately 1,000 RPM. The RPM needle stays constant, and this indicates that the vehicle’s engine is receiving the correct amount of air and fuel.

How does idle speed work on a GMC Truck?

Scan it for codes. The control module controls idle speed with an idle air control (IAC) valve. The desired RPM is based on sensor inputs and the actual engine RPM. Four circuits are used in order to control the IAC valve, allowing a precise amount of air into the intake manifold.

What causes a Chevy Silverado to stall at low speeds?

You might have a bad IAC valve. (idle air control valve) The PCM retracts the pintle in the valve constantly to maintain desired rpm idle, and rpm at low speeds. Its a 4 wire valve bolted on to the throttle body. If its a mechanical problem with the spring or pintle in the valve, it will not set a code for the IAC. If you decide to replace it.

What causes a truck to stall at idle?

Cleaning and/or making an adjustment to the throttle body may correct the problem. Engine running at idle, plug the IAC passage, and the RPM (revolutions per minute) should be at or near 400 rpm. A vacuum leak present could also cause the engine idle to be improperly controlled and needs to be identified before any adjustments are made.

Why does my car stall at low rpm?

The will likely force your computer to stall the engine and only allow it to run at low RPMs, which means the car will only move at slow speeds. This is a safety feature enforced by the computer so that your engine doesn’t get too damaged.

What are the symptoms of low idle, weak acceleration?

The symptoms are: – Idles at just above 0 RPM, all the time (on start, hot, cold, wet, dry, etc) – During acceleration, the scar sputters (as if water were in the gas or something) – If while driving at a high speed (say 60 MPH), I let the RPMs fall to 2K, the car sputters exactly as it does during acceleration

Why does my Chevy truck stall at idle?

Filter is not that old, and if plugged or if pressure regulator is malfunctioning, why do I never see fuel pressure at throttle body so much as waver lower than 12psi? Also, many times the lean condition will start just off idle so bad so that truck wil fall flat on its face and stall.

When to turn off the Check Engine light?

If the engine control module detects an issue with the idle air control valve circuit or signal, it will set off the Check Engine Light to notify the driver that there’s an issue. The Check Engine Light can also be set off by a wide variety of issues, so having the computer scanned for trouble codes is highly recommended. 3. Engine stalling

What causes the idle speed to go up or down?

The idle air control valve is programmed to regulate and maintain the engine idle speed at a constant rate. If the valve fails or has any issues it can cause the idle speed to be thrown off. This may result in an unusually high or low idle speed, or in some cases a surging idle speed that repeatedly climbs and falls. 2. Check Engine Light comes on

What are the symptoms of a bad idle control valve?

$0.00 1 Irregular idle speed One of the most common symptoms commonly associated with a problematic idle air control valve is irregular idle speed. 2 Check Engine Light comes on Another symptom of a potential issue with the idle control valve is an illuminated Check Engine Light. 3 Engine stalling

Why does the low fuel light come on when the tank is full?

All the sudden, the Low Fuel light comes on and the gas gauge is showing empty. I know this is wrong because I just filled up two days ago and have hardly gone anywhere.

Why does my Chevy Silverado stall at low idle?

I have the same problem with the stalling at a stop and low idle. It idles at around 400rpm when warm. It runs fine when cold. When I go from 15 mph to a stop it will stall about 50% of the time. The other times it will recover after the tach drops to almost “0”. I have a 2001 Sierra 1500 with the 5.3 V8.

Why is the gas gauge showing empty at a red light?

So I was sitting at a red light this afternoon with my foot on the brake. All the sudden, the Low Fuel light comes on and the gas gauge is showing empty. I know this is wrong because I just filled up two days ago and have hardly gone anywhere.

What’s the problem with my GMC Sierra truck?

It idles at around 400rpm when warm. It runs fine when cold. When I go from 15 mph to a stop it will stall about 50% of the time. The other times it will recover after the tach drops to almost “0”. I have a 2001 Sierra 1500 with the 5.3 V8. I have done all of the following and the truck has shown no change in behavior. 1. Cleaned throttle bottle.

How to troubleshoot a GM Truck misfire?

This isn’t the only symptom that your GM van, pickup or SUV might experience… here are some more that you might see: P0300: Random Cylinder Misfire. P0301: Cylinder #1 Misfire. P0302: Cylinder #2 Misfire. P0303: Cylinder #3 Misfire. P0304: Cylinder #4 Misfire. P0305: Cylinder #5 Misfire. P0306: Cylinder #6 Misfire. P0307: Cylinder #7 Misfire.

What makes a GM 4.8L misfire engine stall?

P0306: Cylinder #6 Misfire. P0307: Cylinder #7 Misfire. P0308: Cylinder #8 Misfire. Really bad gas mileage. Lack of Power when you accelerate your van, pickup or SUV. Engine may start, run for a few minutes and stall.

Is there a problem with my Chevy Suburban?

I’m trying to diagnose an ongoing ignition problem with a 1996 Chevy Suburban. Sometimes it won’t start, and the previous owner said this happens regularly, and every time the problem occurred, replacing the distributor cap made it work again.

How to diagnose ignition problems with 1996 suburban?

Something which might help you diagnose the issue better is to do an old school trick on your just replaced distributor cap. This would be to generously spray the inside of the cap and the rotor with WD-40. Many people use this as a lubricant to help with stuck nuts and such.

What should fuel pressure be in a GMC Sierra 1500?

I assume there really is no way of testing the the regulator itself considering it’s incorporation. 38 people found this helpful. The test is: 12-15 psi when the key is turned on and the pump will shut off within 3-5 seconds and the fuel pressure should drop to 12-13 psi. 11 being the bare minimum and 13 the Max.

Why does my GMC Sierra 1500 stall at high RPM?

At higher rpm seem almost like the exhaust is clogged but the cat has been bored, itll rev up but just wont really go. Today experienced a poping sound almost like a backfire from underneath. After the truck starts and is warm at a stable idle in park/neutral it’ll rev up fine.

Can a lack of spark timing cause an engine to run rough?

Lack of proper spark timing can cause a different problem: one or more of the cylinders may misfire. That is to say combustion may be disrupted. You will feel, and maybe hear, this as a brief stutter in the engine. You might feel that the engine runs rough or vibrates at idle, say, when you’re sitting at a red light.

Why does the RPM sit at 1500 at idle?

If you don’t find any physical damage, permatex sitting in random places, especially if that random place is important, and the valve body flushes cleanly, get a scan tool on this thing. It is really a matter of finding out what the transmission is doing, when, and why. The other thing, have you figured out why the RPM sits @1500 at idle?

Why is my C / K 1500 surging at idle?

TPS SENSOR BREAK INSIDE THESE THINGS AND CAUSE IRRATIC IDLE. THE IDLE AIR CONTROL IS ALSO NEXT TO IT PULL THAT AND ENSURE IT ISNT COVERED IN CARBON.IF IT IS CLEAN WITH CARB CLEANER

Why does my GMC Truck die at idle?

Once the engine is warmed up then it relies on the O2 sensor for air/fuel ratio. A rough idle usually means a vacuum leak. I would check for those especially vacuum lines.

What causes a GMC Sierra 1500 to stall?

But the stable idle won’t last long, it’ll idle low and rough. Mpg has decreased drastically and give off a rich smell when running. 308 people found this helpful. Bad hesitation off of the start, pumping the gas pedal helps to get her going. Pushing the pedal hard well bog it out and almost stall. 290 people found this helpful.

Why does my GMC Sierra 1500 run rough at idle?