So, I recently changed the pickup coil in my 89 trans am gta 5.7, but now when I cold start, the typical high idle at around 1500rpm doesn't happen anymore. Now I have to hold the throttle to keep it alive and warm it up or it will stall out. And now once it warms up, it idles at around 550-600rpm in drive and park/neutral. Also on top of that, the vacuum hose from my cruise control disconnected from wherever it came from (I think from the intake manifold). But i want to be sure. Any ideas?

 

I suspect you removed the distributor to change the pickup coil. Are you certain the ignition timing was set properly upon re-installation?

The stock idle speed programmed into the ECM is 575 rpm at full warmup, so that idle speed is correct for a fully warmed up engine.

Maybe start with the basics... reset your idle speed...

https://www.thirdgen.org/tpimod2/

 

Yes. I set it back to 6 degrees BTC. I’ll try what was posted in the link

 

If you have a disconnected vacuum hose you probably have a vacuum leak. Fix that first, then reassess your other issues (if they remain).

 

So I connected my cruise control back together and it works fine. But now it’s still 50/50. Sometimes it will start with the high idle and other times it will not.

 

Did you do the idle adjustment procedure?

 

I adjusted the t-20 screw on the idle adjustment for the butterfly valve enough to where it idles normal. Its still 50/50 but now I noticed fuel injector for cylinder 7 started leaking fuel. So now that could be a factor as well. I believe its either the O-ring or its not seated right.