Is anyone familiar with the IAA Unit? Here's my recent experience with my 1992 240SX SE, 115,000miles. I'm the original owner. Symptoms: Fluctuating idle, running rich, engine stalling unpredictably after reaching full operating temperature, little power in 5th gear. History: Replaced Air Mass flow meter at 80k. Replaced O2 sensor at 95k, Replaced plug wires at 95k, running NGK spark plugs. In 1993, had simmilar symptoms and Nissan dealership made an adjustment to the "IVAC" for $50 and cured the problem.What I did to solve it: Replaced the O2 sensor at 115k and noticed a nice improvement for about a week. Then symptoms started again. Took it to Nissan dealership and they told me that they could not replicate the problem. They told me that the "IVAC" adjustment could only be done once. They guessed at the IAA unit and recommended that I make the decision to change it with a new one. $505.00!!! I did. It now runs beautifully. Question: Could the dealership not have "checked" or adjusted the IAA before recommending it be changed out? They didn't want to do that. Was replacing it the only way to go?

After spending the money, the least I could do is learn the details.

Thanks for your help!!!

DJM240SX:D :rolleyes

Those symptons dont exactly match If they didnt adjust it cool.But when the IAA starts to die your idle from running on the highway drops to 0 or close to it the second u step on the clutch.Do a search I had a topic on it.And good god you got raped on the price nissan here qouted me 200.

Thanks. You described it correctly. After running hot on the highway, getting into the city, I'd hit the clutch to make a slowturn (is there such a thing in a 240?), that's when the tach would go to zero. To compensate, I'd step back on the gas to rev it back up again. Not only that, when your engine is about the stall going into a turn, guess what happens to your power steering? It goes too.

Also, thanks for the price comparison info. Here's a little more detail. The actual unit cost was $340 and installation (from Nissan's computer estimator) $130, the remaining balance to $505 was misc. shop supplies and tax. I honestly believed the technician earned the labor part. The IAA is buried in the back and underneath in intake manifold.

It's running fine now.

DJM240SX

Glad you got it fix I know where the IAA sits I was trying to take mine out one day good god thats some cussing woulda been better if i had a lift.