951 idle issues after engine is warm.

[Fast Freddy 944]

I noticed my 951 would start up great every time its cold, but after running errands, I noticed the idle would struggle with out goosing the throttle pedal then it runs great. This only happens after the car has been running all day, and when I run into a bldg. and come back out. Fuel system issue, idle air control sensor issue, or a simple fix? Help a brother out! thanx fast freddy.

[mikepellegrini]

I'd guess it might be a vacuum issue. Easy to check.

[Fast Freddy 944]

Originally Posted by mikepellegrini

I'd guess it might be a vacuum issue. Easy to check.

Thanks Mike, I will be replacing old crusty vacuum hoses, I did add some fuel system cleaner and it seems to be perking up, another gent recommended that I clean the tps, so I'm pulling that out later on and ill give the throttle body a good cleaning also.

[mhariush]

sounds like it could be idle control valve, if you're doing the vacuum lines you should swap that out at the same time if it's the original one.

[v2rocket_aka944]

check the DME temperature sensor and maybe try swapping in a different AFM.
i just fixed a similar-sounding issue on my car by adjusting the hot-start tables (VEMS).

issue was...the intake air temp sensor (in airbox on my car) would get heatsoaked after parking after a long drive and the car would try to start and idle really lean (because it thinks it's really hot).

stock AFM has the air temp sensor inside the case, and your coolant sensor is sort of "high" on the block so the hot coolant might rise to it and throw off its reading.