SO I bought an 86 Z28 for a little over a thousand bucks and I was obviously expecting to have your run of the mill issues. This has proven to be more than what I thought, let me tell you how it went.

Showed up to pick the car up from the guy. He had the hood open with a can of ether sitting on the radiator so I already knew it was bad news. I had to have the car towed home due to some weird problem with the front brakes, it is almost like they are locked down, I have yet to look though so if you have any opinions there it would be great. So I get it home, manage to get it to where it would crank every time, this took a lot of ether shooting and a can of seafoam and some new gas to kill the god knows how old gas in the tank. During this process I found out a couple of things. One, the radiator fan control relay was bad, the altenator was damn near gone, there is an oil leak hopefully from the loose dipstick tube and not the rear main seal, and the most agitating of them all, the car idles around 3000 rpms....

So, my question is do you think this high idle has something to do with the seafoam and/or possible long term use of ether the car was put through or is the setting messed up. If it needs to be adjusted then how do I do that on the 305 TPI to lower it to around 500. Also it may not matter but the car is slightly out of time, I believe it is distributor time and not timing chain but this may or may not be affecting the stupidly high idle, idk. Opinions, help?

 

bump, could really use some help guys.

 

I got the same problem although it goes down to 1100 after awhile. according to my manual it should be idling at 750...

 

The high idle could be a number of things, check the basics. Is the throttle plate stuck open a little, any vacuum leaks? If it were a timing issue i imagine it would be running like a dog and not really contribute to high idle, also check for codes and try and get some live data. Check the throttle plate stop screw aswell maybe someone screwed it all the way out to get it to idle higher

 

This could be a lot of things, but I think the usual suspects are the TPS, MAF, and/or ECM. Here is a thread from a few years ago that might help.

https://www.thirdgen.org/forums/tpi/...s-my-87-a.html

Are you getting an SES light? Any codes to report?

 

No SES or codes, ill look through the thread maybe itll help shed some light for me. Thanks for the reply!

 

My car freaked out on the Power Tour in Madison, Ill. The idle was all over the place but the next day it was fine. One guy said it sounded like it was hunting and I may have a vacuum leak and the GM tech guys said idle air control valve is probably filthy. He said the throttle plates looked clean and the TPS was metering .54v but it could be bad either way. He also said worst case scenerio is a bad fuel injector. But, it has been great ever since that day though.