FBodyshuffle86

Hello gang! Im back, I had a 82' z28 when the terrible happened.. Anyways FINALLY got a 86'IROC BUT it has a swapped 350 in it. It has a idle issue, goes from 600-700 then sometimes stays at 900 then to 1200-1300. I have to rev it a bit and shift through the gears to finally get it back down to 600-700. Summit said Id need to replace the cam.. The block number is 10066036. I dont know if I need to replace the IAC valve or the knock sensor or just swap the cam. I know the 350 was from '79-85. Im new to all this TPI. All my previous were carb. I could really use some help. Thank You!!

Tuned Performance

iTrader: (92)

A cam would be more consistent flares in rpm and just a few hundred rpm.
Sounds like a vacuum leak or iac issue.
You can clean and reset your iac then reset your tps .54vdc .
http://www.iroczone.com/2009/10/clea...rol-iac-valve/
http://www.iroczone.com/2009/10/adju...on-sensor-tps/

FBodyshuffle86

The work order that the couple gave me showed no vacuum leaks upon diagnosis, rather the injectors were too small and were replaced. So maybe just replace the IAC valve?

thtanner

iTrader: (1)

1) Stock injectors for a 350 are 22lb, and 19lb for the 305. If they upgraded motor to a 350 and did not upgrade the ECU, injectors, etc.. then it will have problems, even after swapping injectors to 22lb. The tune will still have a constant for 19lb injectors and stuff won't be right.

2) Do the idle reset procedure first before swapping the IAC, and you can try cleaning it, too!

Tuned Performance

iTrader: (92)

There still could be a vacuum leak upon reassembly of the plenum/runners or in the throttle shaft wear. You might want to clean the iac first . Usually the stick in a position when dirty .
http://chevythunder.com/do_it_yourse...ation_page.htm