Ok, car is running like complete ***. I pulled the IAC, cleaned it (as well as the entire TB), adjusted the TPS and now I get these codes:

22. Low voltage at throttle positon sensor OR Fuel cutoff relay circuit open or shorted to ground

32. Fault in barometric pressure sensor circuit OR Fault in exhaust gas recirculation valve diagnostic switch OR Fault in electronic vacuum regulator valve

33. High voltage (low vacuum) at mass air flow sensor (or MAP sensor)

36. Burn off at mass air flow sensor OR Problem in transmission shift OR Fault in direct ignition system OR Missing pulses in electronic spark timing signal

The car is stumbling, idling erratically, stalling, etc..

I had to bump the minimum idle up to almost 1500rpm just to drive it home. Any ideas? Don't want to, but I may toss it in the shop tomorrow while I'm at work.

Car is a 1986 IROC-Z TPI with 1989 L98 350 installed. It has 24lb/hr SVO injectors, so I'm sure it's drowning until I can get around to re-programming the PROM. Dunno if any of those codes may be attributed to this fact..

 

Go back in time a bit, was the car giving you any fits before you pulled the TB for cleaning?

 

Yes, which is why I pulled it initially. The car would hesitate and occasionally stall, but it was driveable. Not nearly as bad as it is now. The previous owner attributed it to the larger injectors with the stock programming.

 

It could be, but there are several guys running SVO24 injectors with stock programming, car doesn't run it's best, but certainly not as you describe.

First I'd retrace what I did...make sure the little vac line under the TB is on, check for vac leaks aaround the TB where you took it all apart and where it mates to the plenum.

You did use new gaskets? If not, start again..a gasket kit for the TB is about 10 bucks.

You may have the TPS totally fubar...needs to be set when idle speed is correct and IAC is controlling...now that you have the idle screw changes and idle turned up, MAF metering and TPS and RPMs aren't jiving.

Once you get it back to where it was, start with the basic first...i/e tuneup stuff...cap, rotor, plugs, check the wires, replace the fuel filter..at least look it all over. Good idea to always check this stuff out when you first get a car.

Clear the codes by disconnecting the battery for a few minutes as well, then start over.

 

Running a 350-inch engine on 305-inch
MAF programming will definitely generate DTC 33 errors. The only way around that is to repprogram for a 350 inch flow rate. The '36' is a MAF burn off problem.

The '32' is an EGR fault, which is normal if the MAF error is set and the engine is running in Backup Fuel Mode ("Limp-home" mode).

A DTC '22' on your engine is for the TPS signal being too low. That's usually a sensor WAY out of adjustment or a faulty circuit/connection.

You'll need to repair the 22 first, then reprogram the ECM to eliminate the "33" and get your MAF back in control. Until then, it will continue to run like complete and total "***". In the Burmese mountains, that's not a bad thing, either.