Trucker,The rpms don't drop with engine temp if that's what you are thinking.At least 10 min or so before I shut it down.It may have a code but obd1.5 and no ses light coming on.I ordered an adapter for my scanner It should be in this weakened. No worries.I forget what engine I am working on all the time.Hard to keep track and gets worse with age Couldn't figure out why auto correct kept misspelling vacume. Apparently according to google I have been wrong for over 40 years!.You might appreciate the full story.
After getting the motor together I reached in and hit the key.As I am watching the motor run the RPM slowly climes to 4000RPM bouncing off the limiter.Of course at this moment the door swings shut with power locks engaged. I was distracted mid job and forgot to tighten the EGR bolts creating a major vacuum leak.I flooded the engine with throttle body cleaner to shut it down. Got the spare keys to get back in then tightened the EGR and restarted.the motor.It sputtered and coughed out the cleaner then ran good.Let it sit and idle up to temp,turned on the lights and AC.Idle dipped then stabilized immediately like it is supposed to.Shut it down and waited 15 min. Restarted fine.Drove around the the neighborhood for 15 min. of stop and go.all good.Let the engine completely cool overnight. Next day the RPM were at 2000 and it has no torque. It was working to clime a 5 deg incline hill at 60 mph.At one light had to keep my foot on brake and gas to keep it running.Now it is consistently idling too high when I start it.
first thing I checked was vacuum leak. Carb cleaner and propane all over the plenum and clamped off vacuum ports one by one to eliminate a downstream vacuum leak.No change in rpm.Blocked off the EGR port to verify it wasn't stuck open.Cleaned carbon off the IAC pintel and seat. Verified it was actuating with the key. Now that I am thinking abought it there was no oring seal on the iac. Checked the MAP sensor again since I had to pull it off to check the vacuum lines under it.
My plan is install an O ring on the IAC,see if the plugs tell me anything,reset the computer again.