Idle speed and scan results

Good Morning everyone,  I've had a slightly high idle on my '95 Caprice wagon ever since I bought the car a little over a year ago and I now have Scan 94/95 on my laptop so I can actually investigate it using data!

Anyway, based upon the data below, I assume I have a vacuum leak somewhere since the IAC position is at 0, but I would appreciate a second opinion:

ECT:  192
TPS:  0.71V / 0%
IAC Position:  0
Min IAC Position:  10
MAF: 5.62 gm/sec
Target Idle Speed:  662
Engine RPM:  730

Thanks in advance!

Andrew

A fouled throttle body, a stuck PVC valve, or a failed EGR system could be a possibility. Any accessory with a connection to the intake manifold after the throttle body should be plugged one at a time to see the result before suspecting a gasket failure.

There is also a possibility the IAC itself has failed and is not responding to command.

Yes, likely a vacuum leak with the age of the car. Try replacing vacuum hoses or plugging vacuum ports and see if the idle goes down. Also, what's the MAP value (kPa) while idling? Should be around 35kPa without a vacuum leak.

Thanks for the input guys. Looking at my old data, MAP is running 32.86 in gear, and 37.66 in park. I will start digging into the vacuum lines this week. The low IAC #'s make me suspect that it is getting unmetered air from somewhere.

Thanks,

Andrew