Hello everyone,
my first post.

My 92 Blazer had a high idle (1700) and ran a little rough. I replaced a bad EGR. It now runs well on the highway. Idle is awful bouncing between 200-800.
I put in a new MAP sensor. No change. I replaced the IAC. No change. I unplugged the IAC harness and connected a new IAC to see if it moves. (One disconnected IAC in the TBI a 2nd to look at.) Very small movements.
Is this to be expected?

The MAP sensor has 5v power. Some kind of signals are coming out of the IAC harness. When I unplug the vacuum hose from the TBI to the MAP sensor not much changes.

A while ago I unplugged & plugged back in the IAC harness while the engine was running.
Maybe this fried some part of the computer?

Any help greatly appreciated.

Mahalos