Volvo cranks and runs only with help of accelerator

I have a 2001 Volvo s40. It has served me well for 3 years and I haven’t had any major mechanical problems. It has begun to have problems running when the engine is cold. When I crank it in the mornings I have to give it gas and continually give it gas for a few minutes to keep it running. Any ideas of where to begin?

 You need to start by having the codes read. Some places will read them for FREE. Try Autozone or Advanced Auto Parts. Get the exact code (like P0123) not just their translation into English and post it back here.   

How about a little history, when (miles and months) was the last air, oil and fuel filter changes, oil change spark plugs and wires changed?

I will assume that you need to press on the accel pedal to get the engine to run at its normal idle rpm, not keep the engine running at higher than normal rpm just to keep it running. This points to a problem in the idle air control system. I don?t now the Volvo. Typically the PCM controls the opening of a valve that bleeds air into the intake manifold. The valve may be stuck. Cleaning it or replacing it will probably fix your problem. Typically there are no error codes and no check engine light.

Idle Control Motor (Throttle Positioner) may have quit working or the computer isn’t telling it to work. Code time.

When you pump the gas pedal, since it’s fuel injected (rather than having a carburetor), you are actually adding more air, not gasoline. Fouled spark plugs, or a dirty air filter can cause this. If the engine is too rich (fuel / air mixture) at idle, it could, also, be the engine coolant temperature sensor sending a much “colder” signal to the engine computer. The sensor can be tested with an electrical multimeter (“voltmeter”) set on ohms.
Check the condition of the spark plugs. If they have been in since prehistoric times, it’s time to change them.
Get a spray can of MAF (Mass Air Flow) sensor cleaner, and a throttle body (inside) spray cleaner. Their use could make a difference.

I’ve been having the same intermittent problem. My Volvo dealer replaced both the idle air control valve and the fuel pressure regulator. The problem happened again! The spark plugs were replaced 7000 miles ago. What else should my Volvo dealer be trying? Thanks.

Same problem with an '03 S60. No codes, dealer and independent mechanic say it has no problem, and they were unable to replicate. Car has 115,000 miles and is located in downstate NY. The problem comes and goes, but sometimes that car simply won’t start. It has been going on for about 6 months. We replaced the plugs, wires and cleaned the injectors.

If anyone has solved a similar problem, please let us know.

My 2001 S40 is back at the dealer’s again. As I mention in my response just ahead or yours, they’ve already replaced the two most likely components for this problem. We’ll see what happens.