idles to fast

[fielder]

I have a '90 cavalier [2.2] that ran fine until yesterday morning. It started okay, but the idle immediately started racing in it. I checked the obvious, bent cable, vacumn lines or obstructions, but found nothing. Each time I start it the idle immediately races up so high I'm afraid I'll cause damage trying to put it in gear. Any ideas?

[public]

Check for a sticking throttle plate or IAC valve. Also make sure the throttle spring is returning the throttle all the way to the stop. My spring became weak some years back and caused this. A $.69 spring from the hardware store cured it. Good Luck.

[fielder]

The IAC valve is good. I ran a code check and come up with code 51. A local garage told me that a code 51 means the computer is going and want $200.00 to replace it, with no guarentee. I can replace it myself but want to make sure that's what this code means before spending $90.00 for another computer. Any G.M. experts out there have any ideas?

[cdru]

A couple places I did a cross reference say that OBD I code 51 is for a "PCM memory error". I can't say what exactly that means and what causes it, but I wouldn't have any problems beleiving that the PCM would need to be replaced with a code like that.

[public]

Originally Posted by cdru

A couple places I did a cross reference say that OBD I code 51 is for a "PCM memory error". I can't say what exactly that means and what causes it, but I wouldn't have any problems beleiving that the PCM would need to be replaced with a code like that.

Ditto...

[fielder]

Thanks for all the help. The computer was the problem.