I can't seem to figure out the minimum idle, I have set it by the articles shown on this site, but my idle in drive is still 500 rpms, the only way that I can get my car to idle @ 650 rpms in idle is to turn the torque screw out far enough to a point where when I start my car it'll rev up to about 2000 rpms and then trickle off to about 1000 rpms, and then when I put it in drive it'll go down to about 650 700 rpms, and when i put it back into park it'll jump to 900ish rpms. But this also makes my car jump real bad when I put it in gear, since it is idling so high in park.

That is the only way that I can get it to idle at a decent rpm....

What do you think is the problem?

I have an 86 305 TPI with a 700R4
1. I have cleaned the IAC
2. Tried adjusting the minimum air
3. Adjusted the TPS
4. Just seafoamed
5. New plugs
6. New wires
7. New air filters
8. New fuel filter
9. Just changed oil.
It also shows no codes.

 

Hold on. You're doing better than you think you are.

650 is NOT for all engines. I have owned several 86s with TPI and they all idled down around 500-550. I think there are 2 reasons for this....

1. Idle speed is programmed in the chip. You can't change that doing service procedures like this.

2. The factory tach is notoriously inaccurate. One of my 86s showed 450 RPMs idling in gear. It was actually a little higher than that (according to the scan tool) but it looked kinda silly with the tach needle pointing to a much lower RPM than any engine has a right to idle at. i.e. head-fake.

Go back and do your minimum idle speed adustments again and let the ECM hold the idle where it is programmed to and call it a day.

Alternative.... different chip. Some chips have the idle speed set up higher than stock. Also, I beleive the factory even came out with updated chips for 86 TPI engines that addressed several issues, maybe even the rediculously low idle speed. You'd need someone better than me with factory chips to tell you for sure.

 

Huh, Maybe it is okay, thanks! But...

I just thought that 500 rpms was a lil low, since when it's idling that low at a stop light, it'll almost be like it's gonna die, but it usually doesn't, I thought maybe the idle was set too low or out of spec, maybe i'm wrong? Maybe that's normal?

 

Only reason it would be unnaturally low is if your IAC valve isn't working correctly (that's how the ECM controls the idle speed). It sounds like yours is from what you've already said. But on a cold start does it rev the motor up a little and hold a higher idle for a while? If so, it's working for sure.

 

And just to reiterate, absolutely disegard the factory tach and use a separate diagnostic tachometer to set the minimum air positon.

 

Just to be sure, did you disable the ECM spark control before setting the minimum idle? Definitely need a more reliable tach than the OEM.
You could be leaking air around the throttle shaft if the TB is 20 years old.