What causes intermittent stalling in a car engine?

More Causes. One of the more unusual causes of intermittent stalling we’ve heard about is a defective vehicle speed sensor. When the vehicle stops moving, the PCM may not engage the idle speed motor (carbureted engines) or idle air bypass motor (fuel injected engines) so the engine will idle normally.

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 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 does the engine stall when the a / C is on?

Normally, the PCM should increase the idle speed to compensate for the added load on the engine when the A/C is on. But if the A/C signal fails to reach the PCM because of a communications glitch between the A/C module and PCM, the PCM may fail to increase idle speed causing the engine to lug or stall.

What causes an engine to stall at idle?

If the ISC valve is gummed up with fuel varnish or dirt, it may stick, preventing the engine from maintaining the proper idle speed when the throttle closes. A faulty idle speed control circuit may also allow the engine to stall when idling if it fails to compensate for idle loads placed on the engine by the charging system or A/C compressor.

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

What causes idle surges on a car ECM?

What is the diagnostic code for engine stall?

Diagnostic trouble codes P0120, P0121, P0122, P0123, and P0124 are what will commonly appear. The engine can stall for no reason and without any warning. This happens when the TPS gives incorrect information to the ECM. The engine can stall at high speed, at low speed, or even at idle.

What kind of engine is an intermittent combustion engine?

In internal-combustion engine The intermittent-combustion engine is characterized by periodic ignition of air and fuel and is commonly referred to as a reciprocating engine.

What causes a car engine to stop running?

Intermittent faults in ignition modules can also cause an engine to suddenly stop running, and are often heat-related. When the module overheats, it quits working — but starts working again after it cools down (say 15 to 30 minutes later).

What does it mean when your car is running intermittently?

Chasing intermittents is like chasing ghosts. One minute the fault appears, the next minute it vanishes into thin air. Worse yet, the problem may occur at random intervals with no apparent connection to driving conditions, temperature or humidity. And if you can’t get the fault to appear long enough for you to catch it, you can’t fix it.

What does intermittent engine cut-out mean for car?

Most days when the car reaches normal working temperature, the engine shuts down intermittently. This may be only one or more brief jolts or it may stay off for several seconds. This happen while driving 70+ mph on the highway. Ones it passes this phase it continues to run normally for the remainder of my 50 mile commute.

What to do when engine stall Idle Stop?

Aim for the little air bypass holes in the throttle opening. Use the small plastic tube that attaches to the nozzle on the aerosol can to aim the cleaner directly into the bypass port (s). Let the cleaner soak for at least 10 minutes before giving it another blast of cleaner.

Why does my car stall in the Cold?

Engine stalling is more likely to occur during cold weather or when starting a cold engine. So, this kind of engine stalling problem often means the engine is not getting enough fuel and/or too much air. A cold engine needs a fairly rich fuel mixture to start, and to idle smoothly while it warms up.

Why does my Jeep stall when I start the engine?

If it starts, the fuel pump is the problem. If not, the engine should be checked for spark. It could be a sensor or computer-related problem. To be absolutely sure, raise and support the back of the Jeep on jack stands, unless the height allows you to crawl under the back without raising it.

Why does intermittent stalling occur in a car?

One of the more unusual causes of intermittent stalling we’ve heard about is a defective vehicle speed sensor. When the vehicle stops moving, the PCM may not engage the idle speed motor (carbureted engines) or idle air bypass motor (fuel injected engines) so the engine will idle normally.

Is there check engine light for intermittent stalling?

Many times, there will be no check engine light and no fault codes to give you a clue as to what might be causing the engine to stall. So the trick to diagnosing an intermittent stalling problem is to catch the vehicle when it’s acting up — and that rarely happens when you have the vehicle in your shop.

What makes an engine run and idle without stalling?

Every engine needs three things to run and idle smoothly without stalling: a correct air/fuel ratio, sufficient idle speed for the idle load, and a good spark. If any of these is lacking, the engine may stall. Cold stalling problems are the most common because the engine needs a richer fuel mixture to maintain idle speed until it warms up.

Is there a way to diagnose intermittent stalling?

Diagnosing an intermittent stalling problem can be a challenge, especially if the engine only stalls occasionally (and at the least opportune time). And if there are no pending codes, hard codes or history codes in the vehicle’s computer to give you some direction, you may find yourself guessing at a diagnosis.

Why does my PCM stall when I Turn on the engine?

The MAP sensor senses intake vacuum, which the PCM uses to estimate load so it can adjust the air/fuel mixture accordingly. If the MAP sensor isn’t reading right, the PCM will receive bad information and possibly add or subtract more fuel than it should causing the engine to stall.

How can I tell if my car is stalling?

So the trick to diagnosing an intermittent stalling problem is to catch the vehicle when it’s acting up — and that rarely happens when you have the vehicle in your shop. You may have to keep the car and drive it for a few days to see if it stalls.

Can a Dodge Avenger stall at any time?

Stalls can happen at any time, and it can be incredibly jarring when it does happen. Before troubleshooting any automotive issue, including stalling issues with the Avenger, make sure that you check the vehicles trouble codes with an OBD2 scanner.

What causes an engine to stall while running?

Intermittent stalling. Another symptom commonly associated with a problematic crankshaft position sensor is intermittent stalling. If the crankshaft position sensor or its wiring have any issues, it can cause the crankshaft signal to be cut off while the engine is running, which can cause the engine to stall.

Why does my Avengers keep stalling after an oil change?

Ok so for starters the oil gauge is shotty! It will read low oil even after an oil change. Also if this is happening the other glitches are the gaskets in AVENGERS ALWAYS BLOW, everyone i know that drives one also has slow coolant leaks or leaks of some sort that will cause stalling on a consistent basis.

What should I do if my engine is stalling?

Cleaning the idle air bypass circuit in the throttle body with aerosol throttle cleaner; will often remove the gunk and solve your stalling problem. If a good soaking with cleaner fails to fix the stalling problem; check the wiring connector. It might be loose or corroded.

What do you need to know about intermittent stalling?

And if there are no pending codes, hard codes or history codes in the vehicle’s computer to give you some direction, you may find yourself guessing at a diagnosis. Every engine needs three things to run and idle smoothly without stalling: a correct air/fuel ratio, sufficient idle speed for the idle load, and a good spark.

Can a stalling engine be intermittent driveability?

Intermittent driveability problems of any kind are always a challenge to diagnose. When a customer brings you a vehicle and complains of a stalling problem, you may not have much to go on other than their description of what’s happening and when it happens.

What causes an engine to stall while driving?

If the engine stalls while idling or driving, the engine may be running out of fuel. This could be from not receiving enough fuel pressure to keep it running. The most likely cause of this kind of stalling would be, a fuel pump that is not spinning fast enough; or is intermittently cutting out.

What causes a car to stall after replacing the relay?

Replacing the relay usually cures the problem. Another cause of stalling that is often overlooked is bad gas. Moisture sometimes finds its way into underground fuel tanks, and engines don’t run very well on water. Sometimes alcohol additives may not be properly mixed, or may separate from the gasoline in the presence of water.

What causes a car to stall at 40 miles per hour?

The stalling typically occurs while decelerating at speeds below 40 miles per hour. The problem is caused by the calibration of the idle air control valve and evaporative emissions system.

What causes Ford Focus to stall in cold weather?

According to Ford TSB 04-21-13, a cold stalling problem with 2003-2004 Ford Focus models with 2.0L SPI engine during extremely cold weather can be caused by a faulty PCV valve that sticks open, allowing too much air to be sucked into the intake manifold.

What kind of car stalls when coming to a stop?

Random stalling when coming to a stop or slowing down. 2/9/2012 – I live in a steep hilly area & drive a 2002 Toyota Camry XLE with approx 69,000 miles on it. Randomly (approx. 6 times in 3 months)- usually the car stalls on the Parkway when I slow down to avoid or stopping for a red traffic light.

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.

What to do when your Ford truck stalls?

Recently, while coming to a stop. The truck seems to lunge forward and stalls. The only way to get out of the situation is to put the truck in neutral, start it up and put it into drive. This will continue for a few times, but then goes away for days/weeks at a time.

Why does my Ford truck stall at idle?

Sounds like it could be plugging up and causing the truck to stall at idle. When they’re just starting to fail you get flakey behavior for a while, then it starts getting worse. If it isn’t the IAC, then it could be the tranny.

What causes an electric car to stall while driving?

As you drive the electrical components heat up and fail by not allowing electrical current to pass through a particular sensor, connection, computer or control module (This will be the same for electric cars as well). Once an electrical connection cools the system will operate again until reheated.

Why does my car stall after a few miles?

When a bad module is responsible for an intermittent stalling problem, the engine will usually cold start just fine and run OK for short distances, but stalls after driving more than a few miles or when driving at highway speeds (especially during hot weather). It’s as if somebody suddenly turned off the ignition.

What causes an engine to stall while idling?

This can upset the air/fuel mixture causing idle, stalling and hesitation problems. Cleaning the airflow sensor wire with aerosol electronics cleaner; can often restore normal operation and cure the problem. If the engine stalls while idling or driving, the engine may be running out of fuel.

What causes intermittent stalling in a car engine?