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

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.

What should I do if my car stalls and wont start?

If your vehicle stalls and won’t start again, but then starts without issue after sitting for a few minutes, it may be a clogged fuel filter. Fuel filters usually need to be replaced every 40,000 miles or so, but because the filter is the easiest and least expensive problem to address, it’s often a good place to start.

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.

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.

When does a power off turn stall occur?

They are practiced with the wings level or in moderately banked turns. Power-off turning stalls commonly occur during a turn from the base leg to the final approach. The power-off straight-ahead stall can occur when trying to stretch a glide after the engine has failed, or if low on the approach to landing.

Why does my car stall at highway speeds?

The engine may start and idle fine, but run out of power or even stall at highway speeds. If the engine starts right back up after stalling, the likely cause is low fuel volume delivery because of a weak pump. If the engine is running normally one minute, but suddenly quits, loss of ignition may be the problem.

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.

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.

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.

What causes a car to stop in the middle of a turn?

The most common causes for loss of spark include hot shorts/opens in ignition coils, ignition modules and crank position sensors. Loose or corroded wiring connectors that cause a sudden loss of voltage in the ignition circuit will also stop and engine dead in its tracks.

Why does my car stall when there is water in the tank?

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. Bad gas can cause an engine to run rough or stall.

What should I do if my car stalls when I slow down?

If you notice your vehicle stalling when you slow down and stop, park the car in a safe place and book a mechanic to perform an inspection as soon as possible. It is unsafe to continue driving under this condition and could result in further damage to your vehicle. Fast and easy service at your home or office GET A QUOTE FOR YOUR CAR

What happens when you slow down and stop the car?

Your car is designed to run like a well-oiled machine, but sometimes that machine struggles in unexpected places. There’s not always a warning light to alert you of this, but sometimes your car will be driving fine at road speed, only to die when you slow down and stop.

What causes a Ford Escape Engine to stall?

Clogged or restricted EGR Valve: If your EGR valve is clogged, dirty, or defective it can cause your car to stall, idle erratically, or sputter, depending on whether it is stuck open or closed.

Why does my Chevy Equinox shut off at low speeds?

If the torque converter is broken, or if there is a low fluid level in the transmission, the converter will not do its job, and the car will be unable to maintain power at low speeds, which causes the engine to shut off.