kpsfo

I had a really odd thing happen tonight on my way home from work. I stopped by a local fast food place and left my headlights up while I was eating - between that and the radio, my battery drained out. Thankfully someone was around to give me a jump, but when I started driving, the RPMs kept creeping up toward 3000 regardless of what gear I was in. In some cases the car would accelerate without input, and whenever I hit the clutch to shift gears, the engine RPM would spike to 4000+.

I got home okay but it was a pretty uncomfortable 23 miles. This happened once before, about two or three weeks ago, but when the car behaved normally in the morning I chalked it up to random bad / old car behavior.

Anyone have any thoughts about possible root causes? I have an '87 944 Turbo with about 195,000 miles on it. I take pretty good care of it and other than slightly higher than posted speeds on the 101 to and from work, I don't tear it up much.

kpsfo

Just spoke to my mechanic - he said he wasn't sure but he said sometimes the clutch throttle cable heats up when a car is jumped and this can cause it to get hung up (the plastic sleeve around it melts/shrinks). Anyone have any idea how difficult a job that is?

lart951

The clutch Throttle what? it's a hydraulic system there is no cable.

kpsfo

I'll take your word for it - any idea what might cause that behavior?

lart951

while the rpms were mounting did you noticed a speed increase or it felt like the clutch was slipping

Black51

The clutch throttle cable?? And the jumping explanation he gave you was from after the fact the throttle started acting up. So it sounds like this is one of these 'mechanics' you don't wanna be dealing with...

kpsfo

Ah well - maybe I misunderstood. Anyhow, the issue was pronounced for my run home that night, then i took it out for a test drive the next day and within about three minutes the behavior stopped with no repeat since . . . I don't know what to think . . .

OhioState944

I had a similar problem when the cable to the cruise control module was loose. It's in the engine bay just in front of the battery box. Make sure that the nuts where the cable connects to the module are tight. Not sure how this would relate to your car getting jumped though. Maybe just a weird coincidence.

Tedro951

It sounds like the troll-sensor is faulty.

RobE952

High engine RPM, sounds like a vacuum leak to me.

Would have nothing to do with being jump started though. Could be a coincidence.

Vacuum leaks don't often fix themselves either.