For over a year now ive been chasing my idle issue on my car. When sitting at temp idling, it will hunt between roughly 1100 to 600 rpm. Occasionally will stumble and have very little power for a split second when i accelerate from a stop. When desceling in gear it will jerk sometimes and other times give no engine braking force. Intake has been smoked multiple times and no leaks except for very small bit before the throttle body around the airbox. Cold start is commonly at 2000rpm amd will stay there for a few minutes until the engine gets near temp. Sometimes the cold start will be at upwards of 2600 rpm too. Things ive done in the past year to try to correct this issue include, new iacv, new tps, new spark plugs and wires, valves adjusted, pcv leaks fixed, broken airbox replaced, new front o2 sensor, cleaned throttle body. Most recent was the TPS and recleaned the throttle body about a week ago. The spec on the tps is to read 0.5 v at closed throttle. My car being non adjustable on the tps sits at 0.6 v. It seemed to run fine when i first put the sensor on and test drove while watching the scanner data, but now has gotten worse again. Throttle plate has been adjusted as far closed as possible too. Any ideas/tips on what could be my issue?

how's the hose from the IACV to the intake? maybe it

s cracked?

 

is voltage stable?

 

any improvement immediately after an ECU reset?

You might want to remove and clean the IACV.

Lots of YouTube links available on how to do it.

Hose from iacv to vacuum is new. Iacv is brand new and clean. No change for old vs new iacv. New battery as of december. Havent done a test on my alternator. Voltages from sensors looks stable. Only time we saw a bad signal voltage was on the old front o2 sensor

knock sensor???

 

it's a stretch but ?

New knock sensor cuz it threw a code shprtly after i bought the car last year. Placed at the proper angle. Same as everything else, no affect on the issue. Some things have steadied it some, like the new pcv valve, but most have had little or no actual affect on the core idle isse

Don't know if this will help but recently had a very similar problem with my 95.  By chance I noticed a small vacuum line, connecting what to whatI don't know, was disconnected. 

Do you have a picture of it?

I believe i found the cause finally. I was poking at any temperature sensors cause it atarted acting up more than normal since i drove to a cold area. Bumped the main harness connectors behind the right side of the block and it instantly started running correct. Ive noticed zero issues since.