89 S10 4.3 Need help troubleshooting TBI/IAC Idle issue

[ChevyTech]

The sensor is showing a resistance that is not far off. The engine should start and run they way it is supposed to with the reading you got from the sensor.

If the crankcase is getting fuel in it, there is another problem. Could the fuel have gotten into the crankcase before you did the TBI work and maybe you already fixed the problem like fuel leaking from the TBI?

The sensor can be good, but if the wiring to it is bad, the computer will get bad data.

Resistance on the wire, or wire connections, will cause the computer to think it is colder, so more fuel gets injected.

If the ground wires have resistance the same thing can happen. The most important grounds are the ground wires at the front of the intake near the thermostat or manifold studs.

The TBI trucks don't leak fuel into the oil like the central port injected trucks do. I would change the oil, because if that much fuel is getting in the oil, it should be obvious if you look at the TBI with it running.