Would a ported intake manifold cause idle issues? I previously had a BBK 58 mm throttle body on my LT-1 and discovered that since my car is an automatic that wouldn’t work so I went back to the stock throttle body on my very poorly home ported manifold. It will stay running at high idle. But as the rpm comes down to 550-500 it stalls. This is regardless of load. If I rev it up and put it in gear it will happily run at 600 and up but as soon as it gets below that it stalls.

 

Your IAC may be bad in the stock TB. They can get gunked up so clean with TB cleaner. Don't push or pull on tip.

 

I forgot to mention already have a new IAC installed. I know it moves because it will high idle at 1100 then slowly click down until it gets to 500 and then stall.

 

you cleaned the carbon out of the cavity the IAC goes in, right?

 

Yes I did. I’ll try to get a video of it tonight.

 

The file is too big is there a way you recommend getting it to you it’s 52 seconds. Because my Trans Am alway hard starts

 

Use google drive if you have a google account.

 

I'm struggling I hope they're attached because I had to break the 52 sec clip down into a bunch shorter ones in order to even try to attach them from my Iphone.

 

Clip 1 of like 6 I'm so sorry

 

Clip 2 the adventure of still struggling to start. Bless this 75 dollar two year old battery.

 

Clip 3 of Six. Seriously I'm sorry

 

Almost there just one more it was only 5.

 

Yay last one. Car is still searching for idle goes down to 500 and dies.

 

Has anyone been able to watch the video and give me any recommendations?

 

All right no thanks to this forum I finally got it figured out. Rigged up a timing pointer and used a timing light to confirm that I had roughly 86 degrees of timing just while cranking alone. Tore everything apart to find that some how the pressed on plate in the opti that the rotor bolts to had slipped on the driveshaft in the opti. This caused the rotor to be roughly an inch off of where it should be making it pretty obvious why it was so difficult to start, ran extremely rich, and didn't want to stay running at low rpms.

 

Fantastic you found the issue. Your problem would have been extremely difficult to accurately diagnose over the internet. Normally an opti issue is either the engine will not run due to the opti sensor failing or will run very poorly/missing due to rotor screws backing out of the opti and it spinning and firing off random cylinders.