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Why would an engine run fine until it warms up then wont run at an even R P M some times stops?
Wiki User
∙ 17y ago
When your car first starts up, it runs in "open loop mode" meaning it ignores all the engine sensor inputs and simply runs off a base map which is programed into your computer (ECM) at the factory. When your engine light comes on, it causes your engine to operate in a "limp mode" and revert back to open loop mode which is also the base map, so the car can make it to it's destination for service. Once the car warms up to operating temperature, it goes into a "closed loop" mode which means that it now accepts data from all the vehicle sensors (mainly the oxygen sensor and MAP- manifold air pressure or MAS- mass airflow sensor). It uses these sensors to determine the air/fuel ratios and timing advance/retard which is what gives the car optimal fuel economy, power and emission control. I would say that since your car runs fine until it warms up, that you have a bad sensor which is either the O2 sensor (oxygen sensor) or it's a MAP sensor/MAS sensor ( your car will have one or the other). Check your engine codes and see what they say, but It's definitely one of those sensors. It is a sensor but it is the TPS throttle positioning sensor I guarantee it go to your local parts store and but one they are easy to change.
Wiki User
∙ 17y ago
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Why does the engine knock with a cold start but stops when it warms up?
Often a knock when cold is caused by piston slap, which is pistons rocking in the cylinders until they expand in size when the engine warms up.
When the engine is cold it stalls at idle?
i have a 2000 dodge work van 318 engine when i start in the morning it stalls several times until it warms up then ok
Engine runs good at start then warms up and stalls and it stalls at stops?
Check for vacuum leaks.
Why does steam come from tailpipe but stops?
because the warming of the engine causes condensation. and as it warms further the condensation in the motor and exhaust system become warmed into steam until it gets hot all the way through and thus stops because it is not condensating anymore.
Can a o2 sensor keep your 2002 s10 extreme from starting?
No, the O2 sensors are out of the "loop" until the engine warms up.
What could be the reasons for the engine running badly until it really warms up on a 1987 Ford Econ Van 302 EFI?
bad seal/ gasket around fuel injector or intake manifold. as engine warms components expand and form a seal.
Why would your Impala LS make a pinging noise until it warms up?
this is caused from piston to cyl wall clearance when engine warms up the pistons exspand and the noise is less. DON'T WORRY ABOUT IT
1997 jeep wrangler start up in morning clicking sound until engine warms up for about 2 min what can cause it 2.5 engine?
Valves tapping?
What is that squeaking chirping noise coming from the front of your 1997 mercury cougar when it is started up and until the engine warms up?
belt
How do you remove airlock after changing a water pump?
After you install your water pump, fill with radiator fluid. Then start your engine with the radiator cap off. run your engine until it warms up. You will see bubbles forming in your radiator. When the level rises and stops bubbling out, install the cap back on. Dont fill your radiator if your car is on a downhill, you will prevent air from purging out.
Why does 2006 F250 Diesel run bad when cold?
The 2006 Ford F2 50 diesel engine might have a bad fuel injector. The injector can cause the engine to not run properly, until the engine warms up.
1992 c2500 6.5 diesel trans will not go into overdrive when it warms up but when first crank and drive it wil work until it warms Anyone know why?
Try checking the trans fluid. The level of the fluid drops when the engine becomes hot. Check the fluid with the engine idling with the trans in park.
