electrode56

My manual says that when setting the base idle speed that the IACV should be disconnected, the speed set with the idle screw, the IACV plugged back in then then reset the ECU. I got as far as unplugging the IACV and the car died. Plug it back in and it runs ok after resetting the ECU and letting it “learn” the idle pattern again. If disconnected I can keep the car running by manually advancing the throttle. Any thought's here?

electrode56

OK since no one piped up I started thinking about what the problem could be and answered the question myself. I rotated the idle adjust screw 1.5 turns CCW while the engine was running then disconnected the IACV. Now the engine stayed running. I proceeded to adjust the base idle to around 600 RPM then plugged the IACV back in. The RPMs jumped for a second then settled back down to about 600. I stopped the engine and reset the ECU. I started the engine and it was still idling at 600. The manual says it should be at 750. However, when turning on any accessory (AC, Rear Defrost, and Headlights) the IACV seems to hold the RPMS steady.
The FITV is ok since my idle, when cold, is around 1500. I’ve inspected the boost valve for deterioration and it looks ok, I’ve cleaned the IACV, and sprayed the inside of the throttle body with carb cleaner.
I have yet to clean out the EGR ports and will be doing this in the near future but for now the car seems to be running pretty smoothly with the exception that the IACV doesn’t seem to kick up the RPMS like advertised. BTW this car has 366K miles on it and I bought it new.

Lost Again

Not sure of the issue you were trying to solve but the fact you can load the engine (AC, Defrost, blower on high, headlights) and the rpm's hold steady....the IAC seems to being its job IMO.

Again not knowing the orig issue, the only thing you might add is a good TB cleaning-both sides of the butterfly and the ports behind the butteryfly to the IAC and FITV.

electrode56

Thanks for the response. I thought I was alone on this one. I cleaned the TB and butterfly, the IACV the FITV and inspected the air boost valve before posting. Anyhow the original issue was the fact that the car would die when disconnecting IACV when attempting to set the base idle. I fixed that by backing out the idle screw. Now, after cleaning the EGR ports and valve I performed the idle adjustment again. When I pulled off the IACV the RPMS were now 400 unlike the 600 reading I previously noted. So I backed out the idle screw to get 600 then plugged the IACV back in turned the car off and reset the ICU. The car is now idling closer to what the manual says it should be. BTW, I agree that the IAVC is doing its job. I think the only thing left for me to do would be a tune up including a valve and timing adjustment. Again thanks for your response.

Lost Again

Any time, sounds like you are making good progress....