Common questions

What should the idle speed be on a GM TBI?

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What should the idle speed be on a GM TBI?

Insert a T-30 size Torx driver into the Idle adjustment screw that is located behind the plug removed earlier. Turn the screw to adjust the idle speed to 650 RPM +/- 50 RPM. Turn off the engine and disconnect the negative battery terminal from the battery using a wrench.

When did Chevy stop using the 350 engine?

Get the facts on the history and specifications of the Chevy 350 engine, finding replacements parts, and finding Chevy 350 crate engines for sale. Beginning in 1985, Corvettes featured a fuel-injected version of the Chevy 350 engine; other passenger cars equipped with the 350 engine continued to use a four-barrel carburetor.

Where is the fuel injector on a GM TBI?

The GM TBI (Throttle Body Injection) system uses a pair of low pressure fuel injectors mounted above the throttle body opening. Unlike a port fuel injection system, that sprays fuel into the intake manifold runner just above the intake valve, the injectors in this system spray fuel directly into…

How do you change the idle speed on a T-30?

Insert a T-30 size Torx driver into the Idle adjustment screw that is located behind the plug removed earlier. Turn the screw to adjust the idle speed to 650 RPM +/- 50 RPM. Turn off the engine and disconnect the negative battery terminal from the battery using a wrench. Reconnect the IAC valve.

How to order a 350 TBI Chevy performance engine?

Here you can see the 350 TBI engine specs, shipping info, and more! Instant quotes: (888) 957-5454 For optimum service and purchase accuracy all quotes and orders are completed by phone. You can reach by phone at 1-888-957-5454 or email at [email protected]!

What’s the difference between TBI and Vortec in a Tahoe?

If you’ve got a 99 Tahoe, you don’t have TBI – you’ve got a Vortec (dry intake vs. tbi’s wet intake). I wouldn’t go backward in technology. Power and efficiency can both be gained with the Vortec compared to the TBI/carb setup. Thanks for the knowledge!

How long is the warranty on a Chevy 350 TBI?

Our nationwide warranty on the 350 TBI is a whopping 5 years or 50,000 miles. Why? Because we take pride in the engines we build knowing they are our best when they leave here. We use a common-sense and personable approach getting you back on the road as quickly as possible if anything were to happen.

Why is my Chevy Silverado running rough at idle?

Really, your Silverado will be running rougher at any RPM, but a misfire will be most pronounced at idle. Spark Plug Wires – While not every model and engine combination of vehicles today comes with spark plug wires (a lot are now coil on plug), if your Silverado happens to have them, they can go bad and cause a rough idle.

What causes low idle on a Chevy C / K 1500?

Check the Pig Tail connection to the AIR IDLE CONTROL Sensor. This will impact the IDLE if the connection is bad – This will cause spike and low idling if the four prongs are wired wrong or not making proper connections. ABCD AB is Coil 1 and CD is Coil 2.

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.

Really, your Silverado will be running rougher at any RPM, but a misfire will be most pronounced at idle. Spark Plug Wires – While not every model and engine combination of vehicles today comes with spark plug wires (a lot are now coil on plug), if your Silverado happens to have them, they can go bad and cause a rough idle.

What makes a 95 TBI Chevy run crappy?

2–EGR….did you use the VIN # and go to the dealer for the correct one? to test it ,disconnect the vacuum line and plug it and go for a ride. 3–When I removed the cat on mine ,the 02 sensor set the check engine light on and was going thru more gas but didn’t run crappy.

What should I do about my GMC 5.7L TBI?

According to my data, the 5.7 uses a vacuum advance unit on the distributor. Try blocking off the vacuum source temporarily to see if the roughness goes away. (could be over-advancing). If that doesn’t seem to help, try the same with the EGR valve. (too much air, not enough fuel when cold).

What’s the gas milage on a 95 TBI?

Finally, when it dieseled, it threw a CTS code stating that a temp of -40f was indicated (in Houston TX). Replaced the CTS, problem went away, and my gas milage went to 17 mpg (no joke) on a 5.7 TBI with 200k miles. Beat it to fit. Paint it to match.

What kind of truck is a Chevy Silverado?

The Chevy Silverado is a workhouse of a pickup truck. The 2500HD and 3500HD models are made for towing heavy loads. The Chevy Silverado 1500 is the more passenger friendly version that benefited from a redesign in 2007. Luckily, the electrical systems of all Silverados hit more than they miss.

What kind of motor does a Chevy ht502 have?

SDPC’s Keith Wilson said, “The 0282 version comes with Vortec heads and a hydraulic roller cam that produces great low-end torque needed for pulling or climbing, and the engine needs no tuning or accessory changes.” Chevrolet Performance has this hi-po replacement HT502 that will make your fourth-gen C/K one bad body.

Why does my 91 Chevy 1500 die at idle?

WORKING ON MY 91 CHEVY 1500 4BY4 . MY PROBLEM IS THE MOTOR DIES AT IDLE IT HAS THE 5.7 TBI. WHEN YOU LET THE MOTOR WARM UP IT WILL JUST DIE OUT AFTER ABOUT 5 MINUTES IDLE TIME BUT WILL START RIGHT BACK UP THEN DIE AGAIN MAYBE 2 MINUTES LATER. IF I PUT IT RIGHT IN DRIVE AND GO IT WILL RUN FIND UNTIL I HAVE TO STOP THEN IT WILL DIE OUT AGAIN.

Why does my truck idle when its cold?

When youre truck is just warming up, its still cold the efi is dumping fuel because its in like “Choke” mode. As it warms up, it leans the fuel air mix out to acomodate warm engine condition driving. So, when its idleing cold its got the fuel to compensate for the extra air leaking in.

SDPC’s Keith Wilson said, “The 0282 version comes with Vortec heads and a hydraulic roller cam that produces great low-end torque needed for pulling or climbing, and the engine needs no tuning or accessory changes.” Chevrolet Performance has this hi-po replacement HT502 that will make your fourth-gen C/K one bad body.

What kind of motor does a GMC HT 383 have?

With its 3.80-inch stroke [crank] and Vortec cylinder heads, the HT 383 makes awesome torque down low where you need it for towing or four wheeling. A complete re-design was done for the fourth-gen (1988 to 1998) GM C/K trucks, along with a new 4×4 independent front suspension.

Can a bad throttle position sensor cause idle surging?

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. 3) Check Engine Light

Why does my car stumble when I open the throttle?

If there are no misfire codes, a common cause of acceleration stumble is a bad throttle position sensor (TPS). The TPS tells the computer how far the throttle is open. The computer uses this information to determine how much fuel is needed to maintain the correct air/fuel mixture and when extra fuel is needed if the throttle suddenly opens wide.

Which is the best S10 throttle body unit?

Chevrolet S10 Fuel Delivery∕ Chevrolet S10 Throttle Body System∕ Chevrolet S10 Throttle Body Unit Chevrolet S10 Throttle Body Unit Shop AutoZone for Chevrolet S10 Throttle Body Unit. Sort by FeaturedPrice (low to high)Price (high to low)

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. 3) Check Engine Light

Insert a T-30 size Torx driver into the Idle adjustment screw that is located behind the plug removed earlier. Turn the screw to adjust the idle speed to 650 RPM +/- 50 RPM. Turn off the engine and disconnect the negative battery terminal from the battery using a wrench.

Insert a T-30 size Torx driver into the Idle adjustment screw that is located behind the plug removed earlier. Turn the screw to adjust the idle speed to 650 RPM +/- 50 RPM. Turn off the engine and disconnect the negative battery terminal from the battery using a wrench. Reconnect the IAC valve.

What should the idle speed be on a Silverado?

When I have my AC on, which is all summer here in Phoenix, it works great when the idle is just above 500 RPM, but if it dips below 500 the AC turns to warm air (not good for the attitude when in the summer heat of Phoenix).

Where is the IAC valve on a Silverado?

Also take a look at your IAC (Idle Air Control) valve, usually located on the side of the throttlebody. They are very easy to change out and tend to go bad. I had a similiar problem and replaced and cleaned may things, still had issue and got truck tuned with a slightly higher idle, as soon as I did it was golden.

Where is the idle control valve on a Chevy Vortec?

The idle control valve sits on the throttle body and is responsible for adjusting the amount of air that enters the engine at idle, ultimately controlling engine idle speeds. At idle, the valve blocks a small amount of air from entering the engine, keeping idle RPM’s low.

What are the symptoms of a Chevy Vortec engine problem?

Symptoms of Failing Idle Control Valve and Throttle Position Sensor 1 Rough idling 2 Engine stalling 3 Hesitation during acceleration 4 Hard shifting and lack of power 5 Lack of accelerator responsiveness 6 P0122 engine code (TPS sensor)

When I have my AC on, which is all summer here in Phoenix, it works great when the idle is just above 500 RPM, but if it dips below 500 the AC turns to warm air (not good for the attitude when in the summer heat of Phoenix).

How to help me with a Chevy k1500 misfire?

× Help us help you. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc.) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a solution more quickly and easily!

How to troubleshoot your TBI fuel injection system?

Troubleshooting your TBI Fuel Injection System Most of the problems encountered while installing your fuel injection system or after a time of operation are very simple. If your check engine light is on you more than likely have a hard fault meaning something is grounded out, unplugged, operating out of range or has gone bad. See

What is the TBI code on a 1990 Chevy truck?

Consult a service manual or see below for any check engine light code definitions. You can use a late 80’s or early 90’s GM TBI definition. If you have access to a scan tool use a hook up for a 1990 350 cu. in. 5.7L Chevrolet truck. For some scan tools enter VIN 10th“L” 3rd“C” 8th“K”.

Where is the pickup coil on a TBI engine?

5 people found this helpful. One of the MOST overlooked parts of these TBI engines is the distributor pickup coil. It’s a component of the distributor which plugs in to the ignition module, the same module that sticks out the side bottom of the cap that the coil also plugs in to.

Why does my TBI 350 have zero power?

This weekend I put a new idle air control valve and o2 sensor in, and the symptoms still persist. Along with the erratic idle, the engine has absolutely zero power. It stumbles as if it’s missing a couple of cylinders when you accelerate.

Why does my GMC TBI keep stalling out?

Sometimes it will try to run for 7 or eight seconds, rpms going up and down till it stalls out. Any chanced it could be in the distributor someway? The following are the reading I got on my last test.

Troubleshooting your TBI Fuel Injection System Most of the problems encountered while installing your fuel injection system or after a time of operation are very simple. If your check engine light is on you more than likely have a hard fault meaning something is grounded out, unplugged, operating out of range or has gone bad. See

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

How does the GM TBI fuel injection system work?

The GM TBI (Throttle Body Injection) system uses a pair of low pressure fuel injectors mounted above the throttle body opening. Unlike a port fuel injection system, that sprays fuel into the intake manifold runner just above the intake valve, the injectors in this system spray fuel directly into the throttle body above the throttle plate.

Where is the idle button on a GM TBI?

The “A” and “B” terminals are located on the top right of the connector. Unplug the IAC valve located on the passenger side, rear of the throttle body. Start the engine. Insert a T-30 size Torx driver into the Idle adjustment screw that is located behind the plug removed earlier.

What kind of engine does a GMC Sonoma have?

The 2.8-liter V6 is acceptable for most requirements, while the 4.3-liter sends these trucks to the head of their class for acceleration and towing. Syclone models offer brutal performance with 0-60 mph times under five seconds. A 4.3-liter long-bed Sonoma with automatic averaged 21.5 mpg.

$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

When did GMC change the S15 badge to Sonoma?

GMC replaced the S15 badge with a Sonoma designation as the compact trucks earned a facelift consisting of a new grille, wheels, bodyside moldings, and bumper rub strips. Later in ’91, the base 4-cylinder engine added power.

How to remove Idle Stop cap from a GM TBI?

On a factory TBI unit the idle set screw will be capped from the factory so you cannot mess with it. But you just knew one day you would. Not all caps look like the one pictured but this is the one that is hardest to remove. The easiest way is to first grind the cap flush with the surface of the throttle body.

Is the idle set screw capped from the factory?

On a factory TBI unit the idle set screw will be capped from the factory so you cannot mess with it. But you just knew one day you would. Not all caps look like the one pictured but this is the one that is hardest to remove.

What happens to your car when you idle?

A rough idle will result in intense vibrations forming whenever your vehicle is stopped with the engine running. Since less air will be going into the engine during its idle state, the car will react by shaking profusely.

What are the symptoms of a bad idle air control valve?

Below are the top 5 symptoms of a bad idle air control valve which you will easily notice. Since the idle air control valve is supposed to manage the idle speed of the engine, a bad valve will certainly throw that out of whack. It will cause the idle speed to randomly fluctuate to different speeds rather than stay at one constant speed.

Why is the EGR valve at idle not working?

This could be caused by one of two possibilities… either the EGR solenoid is defective or the vacuum hose is attached to the wrong port on the EGR solenoid. Resolving this ‘continuous vacuum to the EGR valve at idle’ problem will solve the EGR valve and rough idle issue.

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 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.

Is there an engine misfire code on a GM 4.8L?

Engine Misfire or Rough Engine Idle on GM 4.8L, 5.3L, 6.0L is becoming; more common and getting harder to diagnose. 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.

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.

Where does the vacuum leak come from on a TBI?

There are instances where the vacuum leak is coming from the adapter plate used to attach the throttle body to the manifold. If this is the case make sure that the seal is positive between the manifold and the adapter plate; also between the adapter plate and the throttle body.

Consult a service manual or see below for any check engine light code definitions. You can use a late 80’s or early 90’s GM TBI definition. If you have access to a scan tool use a hook up for a 1990 350 cu. in. 5.7L Chevrolet truck. For some scan tools enter VIN 10th“L” 3rd“C” 8th“K”.

What does it mean when your engine idle is too low?

If your idle is too low, it could be the IAC not talking to the computer correctly. Disconnect the IAC connector for a couple seconds while your engine is idling. If your engine idle didn’t change, you can suspect it to be the IAC. If it is working properly, unplugging it would cause your idle to freak out.

What causes a caravan to run rough at idle?

Really, your Caravan will be running rougher at any RPM, but a misfire will be most pronounced at idle. Spark Plug Wires – While not every model and engine combination of vehicles today comes with spark plug wires (a lot are now coil on plug), if your Caravan happens to have them, they can go bad and cause a rough idle.

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.

Why are the spark plugs on my Dodge Caravan not working?

Spark Plugs – One of the absolute most common causes (if not the most common reason that your Caravan may be misfiring) is the spark plugs. Although most modern vehicles use iridium spark plugs, they still need to be changed at the manufacturers recommended interval.

Why does my Chevy truck shake at idle?

While the truck is idling with 02 lean, a quick shot of carb spray in the throttle body will cause the 02 to go rich. And when the truck sometimes starts shaking at idle it will smooth out with carb spray. I jst don’t understand why the computer is not trying to richen the mixture up based on the 02 saying lean.

Why does my 1993 Chevy TBI stall at idle?

Timing is steady and not jumping all over. It is a fuel issue. The only code that ever sets is a P044, lean exhaust, and the exhaust is really lean. We have swapped PCM/PROM with a same year Suburban, no change. Both vehicles run the same as this did using the other’s PCM.

The exact setting is on the emissions label on the radiator shroud, but in general, the idle speed should be about 500 RPM in Drive, 700 in Park / Neutral, or if you have a manual transmission, somewhere between 600-800 RPM.

What should the idle RPM be on a car?

Your engine should normally get to around 700 RPM after you start the vehicle, depending on the model. If your idle is way off and you have one or more of the problems listed above, then you will want to diagnose the issue right away.

When is the best idle time for a truck?

Rough idle when in drive..but idle is fine when in nuetra… Truck idle is rough when in drive with no acceleration (stop signs, red lights, traffic) but idle is fine when in park or nuetral. . Check engine light just started flashing recently

When does the idle air control valve change?

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. The idle air control valve is responsible for managing the engine idle speed.

How to time a Chevy inline 6 cylinder?

How to Time a Chevy Inline 6. The firing order for a Chevy inline 6 cylinder is 1-5-3-6-2-4, and the timing should be 4 degrees BTDC (before top dead center.) The cylinders are numbered in order from front to back. The initial timing must always be set with the vacuum advance on the distributor disconnected so base timing can be seen.

Which is the most reliable transmission in GM?

In case with the 5НР series, especially modifications 24 and 30, high-quality ZF transmission parts often allow reaching the milestone of 500 000 km, even under intensive operational loads. GM 5L40-E / 6L50

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Ruth Doyle