!!!!!!!!!!
Second, I noticed there was a lot of engine noise, and sounded like an exhaust leak. under the car at the bottom of the exhaust downpipe there was a hole the looked like was punched there, and is threaded. So I screwed in a 1/2" long 5/16 bolt to plug it. Anybody know what the function of the threaded hole is? Im certainly more quiet now.

Sounds like you're missing an oxygen sensor to me! Is there a plug the color of uncooked white rice (whitish, kind of opaque) halfway along the firewall, with nothing attached to it? If so, there should be a corresponding 2-pin black connector present for the O2 sensor's heater.

The idle switch or throttle-stop set-screw can be misadjusted and keep the car from getting the signal that the throttle plate is closed and it's time to run the idle system.
Check that the throttle plate is closed. Also check if the throttle/idle switch clicks when you start to open the throttle plate. Should click within 1/8" or so of rotation. Less would be better.

The wires can also back out of their crimps and leave the metal connectors on in the plug intact, but I think that only happened on my frankencar.

Good Luck. A photo might clean things up a lot.
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1990 740 Turbo, on its way to stock specs, maybe beyond