[cyberpine]

The last mechanic that worked on the truck told me I have 400 turbo and he based that on the distinctive pan shape. I don't have a good pic to confirm that , and really not sure otherwise how to confirm what transmission I have. I do wonder if my base factory 305 with came with that transmission. He says there was no port on that transmission to connect to the TB.

Will try to do these two tomorrow. I never noticed any moving parts int he in the IAC.

Should be interesting as I've never adjusted idle RPM on this truck either.

from your earlier post:
1) Lets clear all those DTC codes as they were artificially induced. This is easily done (engine off) by disconnecting negative Battery terminal for about 30 seconds. ECM will clear its fault memory from these codes until it sees subsequent fault conditions.

2) After clearing ECM fault memory we need to make sure that IAC (Idle air) is correctly reset and knows where it is. The procedure is very simple:

a) Place ECM into diagnostic mode by shorting pins A&B - this will force ECM to command IAC to continuously move into fully close position.
b) Without starting engine, ignition in run position you should be able to hear clicking noise from IAC being jammed into full close position. You can see IAC pentacle fully closing idle air passage in the TB (10 o'clock).
c) Remove the connector (It is 4 wire arranged in box) from the IAC and start engine while monitoring idle speed. Minimum idle speed for a stock engine should be around 450 rpm (can be adjusted).
d) Shut of engine, remove A+B jumper, re-connect IAC connector. Restart engine - idle should be around 600-650 RPM. Provided that base timing is correctly set and there are no vacuum leaks.