ducsfly

Help needed....My '84 944 has an intermittent rpm issue. When started cold the engine idles fine, but won't rev past 1500 rpm. As the engine warms the rpm goes up. It sounds/feels like a plug has been pulled. When the engine is fully warm it revs just fine. Also, it seems to be more of an issue when it rains. Any ideas?

While I'm wanking- the cooling fans seem to run alot. Engine temp stays normal(about 1/2 on the gauge). They don't come on until temp has been at 1/2 for awhile, but then it takes a LONG time for them to stop. They also run when cruising at highway speeds. I was under the impression that airflow at hwy speeds should keep the engine cool enough w/o fans.

Thanks for any/all help.

jmd_forest

1) Check for vacuum leaks in ALL the vacuum hoses, big, small, and in between.
2) Check DME Temp Sensor
3) Check/clean ISV
4) clean up engine grounds

jmd_forest

944Ross

The fans are controlled by the switch in the radiator. They are dirt cheap, and come in different closing temp's. You'll have to pull the fans to get to it, not a terrible job. On the other hand, is it possible your cooling system needs cleaning? Maybe the fans are doing just what they should, and it's your radiator that is falling down on the job.

ducsfly

Vacuum hoses OK, most have been replaced.
Will have to look for DME sensor.
What is ISV?

The head gasket was blown/fixed and I am satisfied engine area of cooling is OK, which leaves radiator as weak point. I'll have to check on fan temp sensors. BTW, car started and ran fine this morning.....Frustration!

spoolinturbo

ISV = Idle Stabilization Valve

ducsfly

Thanks for help guys. I am out of town now, but plan to get on it this weekend. My son tells me that now the fans run in high mode after car is shut down ( he pulled the fuse to get them off after 30 min run time). So....it looks like fan temp sensor will be 1st area attacked.