96 SL1 Over-Revs at Start

Thanks in advance.
My daughter's '96 SL1 does this often (not always) at a cold start.
Starts fine and idles up to at least 2k RPM. Stays there till it warms up a bit I guess. Sometimes RPM can be lowered with a quick stomp on the gas (not always). Normal idle is 600-800 RPM (?)

ANY ideas about how to fix?

Steve

Clean your throttle body.

Replace the ECTS. Ive posted a video for this around here somewhere.

Then if problem persists:
During a high idle, shut the car off then back on. See if the idle returns to normal. A cold start idle is around 1100-1200. If it does, this indicates an issue with the TPS.

Thanks. Haven't diassembled it but shot it w/a carb cleaner.
Hasn't happened again...so far.

Thanks. Haven't diassembled it but shot it w/a carb cleaner.
Hasn't happened again...so far.


Take it off and clean it. Dont be lazy!!:iceslolan

If cleaning the throttle body doesn't work, it could be a bad Iac motor, it doesn't necessarily mean its the ect sensor, maybe check the ect sensor to see if its the old ceramic 1 or if its cracked. The only real way of deeming the etc and the Iac is with a scan tool making sure that the parameters are within range.

I just got a 97 SL1 and it dose this too. When it warms up, the RPM's go to normal, but when I go to shift gears, the RPM's go up about 2-3k, then it slowly teturns to normal. It will go up, eventhough my foot is off the gas peddle. I will try the cleaning the throttle body to see if that works. I even have one out back to put on that looks cleaner already. Its from when I rebuilt my 92 SC2 engine, I used an SL1 for the bottom end, so I still have the block, head and intake for the SL1 just sitting around.

While your under there, replace the ECTS with a brass one. Also check the intake manifold gasket. Spray it with brake cleaner with the car on and listen for idle changes

If its not the intake, its IAC motor.

Just happens that the spare parts out back had the IAC still on it. I replaced that and it works normal again. At first, the engine almost slalled a few times, I guess the computer was learning the new inpute readings. After a test drive, it works normal now.

Yeah, they can be a real pain to learn sometimes, expecialy when they are new, they rev really high for a long time. Good to hear its fixed :biggrin: