Got a little problem here, own an 85 Iroc 305 TPI, only 26,500 original miles on it. When the car is warmed up, shut off, then restarted, the RPM go from 5000 to 15000 then back and forth, had the thing at a Chevy garage, they can't figure it out. Had it on the computer, no codes, and when he hooked the thing up to the computer, the RPM's would be normal, when he disconnected the comptuer the thing went whacky up and down again. They checked the vac. for leaks, the injectors, etc. They THINK it could be the MAF or the IAC...not sure and they won't replace that incase it is not the trouble! What else could be making the car RPM's run up and down after the car is warmed up and shut off then restarted??????

 

Has the IAC been removed, cleaned, and lubricated? Has the throttle been checked for binding and/or varnish accumulation?

 

I HONESTLY think because I am a "WOMAN", they are reluctant to let ME tell them what to check. I am taking the thing "BACK AGAIN", and telling them to literally remove the IAC and clean it and check the throttle body for build-up! This just p.o.'s me because I had the car to 3 people ! YES 3, and no one seems to know what it is!!!! ARGH!

 

Well, had the 85 Iroc (305 TPI) "BACK AGAIN" to another garage. They cleaned IAC, Checked stuff for "build-up", replaced the MAF (costly little sucker!), and checked the hoses for a vac leak, took the injectors out to see if they were leaking, checked for loose wires or corrosion, ran all these tests on it..... got it back, (after a week in the shop! ), and STILL.....after it is warmed up, and sitting a few minutes, and restarted, those RPM's are searching! It is a "little better" going only from 7-10 instead of 5-15 (x 1000). After about 5 or 6 times of searching, it seems to stop. I ran a half tank of gas, 87 grade ( $20), out of the thing, just to drive it around, and shut off to test the RPM'S.....dunno what it is? I guess it is "ACCEPTABLE" and I have to live with it. They don't know.....(Took it to a Chevy dealership, thinking they would help me out). The performance is great, and idles fine. It is a mystery. Anyone have that similiar trouble with their 305 TPI's?

 

I am having a very similar problem with my 89 tpi....I unplug the MAF and it runs/idles fine...plug it in and it goes up and down a bunch till it dies....
this is all on a zero mile new motor (rebuilt)

 

I will say that it NEVER died on me, just as it seemed to want to stall, the thing would kick in and shoot the rpms to 15.....now it is up to about 10, just one of those things I guess I gotta live with! They even pulled the fuel rails off and checked the injectors and the started injector for a malfunction! NADA!~