Try this. Idle should be 650 rpm in neutral with the engine warm. When you pull it in gear, it may pull down a little but come right back to 650. Around 900 rpm cold. If you don't have access to a scantool, there really isn't any way to test the IAC ir ECM function. It would be cheaper to have a shop check it than buying a new one or ECM.doctordick said:Had a thought today (hate when that happens) Is your IAC working? That could account for the weird idle and cause a lean condition at wider throttle opening. Foot off the gas, engine warm, does the RPM come back up when you put it in gear or start to drag the clutch ? If you have access to a scantool, you can operate the IAC with the engine off. If not, you should be able to watch it operate with the engine running by removing the air cleaner and spacer ring and looking straight down into the opening above the end of the IAC. Try it with the engine cold, the pintel should extend and then slowly retract as the engine warms up. That's an advantage and a disadvantage of the earlier computers, they can only tell if a part is shorted or open, not if it's just not working mechanically. That lack of diagnostic power is also what lets us get away with murder without reprogramming compared to the newer engine systems. Hope this helps, lemme know.
I'm over 100 miles from you. What type of meter did you use? Did you read 5v or 1/2volt? (hard to see on my screen) Did you try to drive it with the MAP disconnected? It should have run pretty normally if the MAP sensor was the problem. If you were only reading 1/2 volt on the grey wire and across the grey and purple wires, that's way too low. Since you've subbed the ECM, the problem would about have to be in the harness or a ground issue. Are you using an OEM harness or aftermarket? The OEM harness has two black wires with white tracers that end together in an eyelet terminal. This is the ground for many of the functions (not all) And it needs a really good zero resistance connection.RBaker said:Alexander City, al how about you
That's a good question that I didn't ask, but more cam duration would cause vacuum to be low and it seems his MAP sensor is reading too high (lower voltage) Low vacuum = higher voltage, high vacuum = low voltagemusselman said:Are ya'll running a stock tbi cam???