I just bought a 86 iroc 305 auto trans everything is stock to my knowledge my problem is that number one the car idles high tach is off so I'm not sure what it's idling at but I can hear it the car also is throwing trouble codes #'s 41, 25, 53, 52, 44 do you guys think the computer is junk or what? Car runs fine never stalls or anything sometimes it starts hard (like cranks over quite a bit before it fires then kinda weak when it starts but then idles high again) any help would be great!!!

 

Welcome aboard thirdgen.org.

An '86 IROC could have the carbureted LG4 (8th character of the VIN = H) or TPI LB9 (8th character of the VIN = F). Which do you have?

It's actually pretty rare for the computer to have a problem, and when it does, it's even more rare for it to tell you what's wrong with it. When codes are set, it's typically a result of input from a sensor.

I'd suggest clearing the codes (https://www.thirdgen.org/service-eng...ht-error-codes) and driving it some more, see if any of the codes reset.

Code 41 will be set when the timing is adjusted. Takes awhile for it to clear on its own afterwards unless you reset it per the link above.

 

I have vin letter f. It's the 305 tpi, I cleared the codes so I'll check them again tomorrow when I get to work. It never had a check engine light on either I just wanted to see what the rpms were actually at when idling but I happen to stumble on the dtc codes instead.

 

So after clearing the codes driving a little I checked the codes again and got this list, 25, 41, 44,51,52,53,54,55. What could be the problem it seems to run just fine???

 

So after clearing the codes driving a little I checked the codes again and got this list, 25, 41, 44,51,52,53,54,55. What could be the problem it seems to run just fine???