Car sits all night in the garage. I start the car in the morning and it immediately stalls. Turn the key again and I have to step on the gas pedal to keep it running (won't hold cold idle). Once the car warms up a bit it runs fine but if it is still cold it will stall as soon as I slow down for a stop light or stop sign. Is this the Idle Air Control Valve or the Fuel Pressure Regulator (ordered the new FPR from eEuroparts already)? One other thing: it does not do this every day. For the last three days it's been fine with the occasional two times to start the car but for the most part the idle stays above 1000 RPM when cold.

 

Well, 2 catalogs we have now. If fact I realize the problem might not be limited to a single catalog, I mean maybe some issues come from the FPR, while others come from I.A.C., especially for a high mileage car. The issues from different catalogs make it complicated to analyse the root cause.
Would you give more description on the morning starting? for example, if it cranks, how much time or how many cranks?
"it does not do this every day", are there any differences between the weather for the days, such as rainy or cloudy, cold or hot?
Btw, have you had the I.A.C. cleaned? you know, 154k is long...

 

What I have noticed is the longer the car sits the more likely it is not to start without my depressing the gas pedal. Today for instance the car did not start the first time I turned the key but as soon as I gave it a little gas it started and it idled normally. This was after it sat over night (roughly 12 hours of not running). Weather does not seem to have any bearing on it. I'm still waiting on my parts.

 

I have my FPR replaced last week, since then the engine start at the fisrt crank.

Before that my 02' S40 sometimes hesitated start, and then wouldn't fire until crank about 8-10 times, especially under hot sunshine, but never failed as long as I kept the key on. Pushing the oil accelerator could make a little help to reduce the cranks. After start, it worked well without any problem.