Move over idle, here's something leaner. - - - Discussion level MASTER

The RPMS move over idle when I go to shift instead of dropping, the RPMS increase. I checked codes and got 35 (idle air speed control) and 44 (lean condition). I changed out the IAC and no change occured. We are talking about a 1989 Chevy Cavalier Z24 5 speed, FWD, 6 cylinder, with balls like no other FI vehicle from the 80’s I’ve ever run across.

Forgot to clarify that the car has to be moving and while either out of gear or ppushing the clutch down the RPMS increase. If the car is stationary, it doesn’t matter what gear I go to put it in the rpms will stay low. This is my 4rth clutch I just had replaced a week ago. Please help as I feel like I’m living in the movie Groundhog Day and I have to keep getting clutches installed every time I turn around.

Check for an air leak at the throttle body or intake manifold.



  1. Vacuum leak
  2. O2 sensor
  3. MAP sensor
    Has any one of those items been replaced.

Will do, That’s what I was thinking. When I got the IAC it didn’t come with a gasket, so I used the old o ring form my 12th (jk)MAYBE 3RD OR 4TH IAC I bought before this one…

this is my 3rd try at answering you. I have replaced and still have 3 other working MAP sensors, tested with a voltmeter. The O2 sensor maybe over 3 years old, so I am to presume that is a strong possibility. The vacuum leak is what I was thinking mor so then anything else. I remember in school my mechanic professors would use either propane or kerosene (not sure if I’m even in the right ball park), but they used something that if the car had a leak this would increase the RPM’s drastically if it were sucked into the engine from a leak point…