Quote: You might try directing some propane from an unlit torch into the intake to the air filter after the engine is fully warmed up. (when started cold the air fuel ratio is very rich anyway)
If one or more of your fuel injector tips have deposit build ups interfering with the short solenoid plunger up down at idle, the extra propane should smooth out the idle.
If the IAC is working correctly it should adjust while this is happening and RPM should keep returning to spec as the propane is quickly added or taken away.
While you have the propane torch out check for air leaking past gaskets or o- rings.r
Carbon deposits on the backsides of intake valves can also cause a rough idle.
If you are going to keep driving it add a bottle of Chevron Techron Plus to your next tank, a bottle of Gumout Regane to the 2nd tank, then a bottle of Redline SI-1 to the third tank.
This is about the cheapest thing you can do considering the cost of man-hrs and based on the idea that: "what one cleaner cannot dissolve, another one might".
The car runs great above 800 RPM. I will try some of the additives to see if that helps.
I'll let you know if anything changes, but I am accepting the fact that I just might have a slightly rough idle for the rest of the days I own this car. With the cost of cars going up and up, I plan on driving this car into the ground.
