To continue the discussion concerning idle problems on 82 crossfire's, let me add possibly a new condition. When starting my car cold it has a good 1200 rpm or so fast idle, the thermac damper is closed on the air cleaner inlet and idle is smooth. After 15-20 seconds, the idle slowly starts to die off and after 5-10 more seconds, the idle stumbles to keep the engine fired. The rpm falls to below 400 and then climbs to 1200 and then back to 400-500 again, like a yo-yo! It stays this way, up and down, so I  hold the pedal at 1200 rpm and the engine runs fine and after warming the engine this way for a minute, it idles by itself around 600-650 rpm. I noticed the damper doesn't open once the engine is warm and only opens when the engine is shut off, so vacuum is working there. How do you check the temp sensor in the air cleaner? Once then out on the road, no issues with hesitation, no stumbles and idles fine at stops. My car is completely stock... new plugs, wires, K&N filters, vacuum hoses all checked with a MiniVac (had to replace a few), manifold bolts and TB screws all tight, new ECM/Prom and only 34,750 original miles. I'm thinking age has something to do with the condition vs. miles! How to you check the IAC's, TPS, MAP, VSS and coolant sensor for sticking or failure vs. just replacing?  EGR seems to be fine and I have a new PCV valve coming just to make sure!

I had similar problems at one time and finally changed the O2 sensor,  the temp. sensor (at front), and the mapp sensor and it ran fine after that.

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Lifetime Member #116
Dave's '82

   

I doubt the damper on the air cleaner would be the problem.   It helps the engine warm up but Ive disconnected mine before and car runs fine without it so I would look elsewhere for the problem you have.  Like Dave,  Ive had idle problems too and they seem to be a common factor with crossfires.  I have also replaced my mapp sensor, O2 sensor and more importantly, the coolant temp sensor on the front of the engine.  Id start with replacing the temp sensor then proceed to the 02 sensor and mapp sensor if the temp sensor doesnt make any difference.  There is a procedure to check the tps in the factory service manual.  If you have a code reader its fairly easy, if not there is a procedure for doing it with a multi-meter posted somewhere.  Ill look for it if you need it.  Also, you may try http://www.crossfire.webhop.net/  these folks live, eat, and breathe crossfire injection.

I guess I'm confussed because it only happens on cold idle! Once I hold the pedal at a steady speed for a minute it maintains a good idle from there out. With that said... what isn't working at cold temperature vs. a warm temperature? Does that make sense?

I noticed your seats with the emblem stiched in! Where and what material if you don't mind me asking. I want to replace mine with a more durable material.

I would think the  coolant temp sensor to be a likely suspect but sure cant guarantee that.   The sensor is easy to get to and not an expensive part.  I think I would invest a few bucks in changing it.  Ecklers is proud of theirs at around 50.00 but  the local Advance Auto has one for less than half that.  The seat covers are leather with vinyl sides as the OEM ones were.  I ordered then in from www.riksvet.com and had a local monogram shop to embrorder the emblem.  I used a photo of my 82 crossed flags for him to work with.  If you decide to have it done, I have an image you can provide to your monogram service.  Most upholstery shops around here wont do monograms like that, I was lucky to find a shop that does shirts, baby blankets, etc that would do it. The monogram shop charged me $45.00 for both covers, I was pleased with the price and workmanship.

My guess is the coolant temp. sensor also. The O2 sensor is ignored by the computer untill your up to operating temp. The mapp sensor is easy to check, just pull the vacuum line off it and put your finger on the open end of the vacuum hose, you should notice a change in the way the car runs, if there is no change then the mapp sensor is bad.

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Lifetime Member #116
Dave's '82

   

Sounds like your IAC is sticking, they should be cleaned every 30,000 miles. Remove and spray with injector cleaner, to remove carbon. I just did it to my truck thats TBI.

I picked up a new coolant sensor today and will install as soon as it stops freezing outside where I can work in the garage without gloves on! It sounds as if a cat and mouse game (process of elimination) to find the problems of idle on CF's!? One other question to pose... why doesn't a code appear in memory? Code 14 is coolant sensor voltage is too low; 15 is too high; there is code 33 & 34 for the Map sensor and even 13 for the Ox Sensor cold voltage! Food for thought. Kudo's to CF's!

Don't throw parts at it! Find someone with a scanner to "read" what's going on with the engine at start up till it is to go into closed loop (the computer takes over).

After installing the sensor, disconnect the battery for a few minutes to clear the memery. It will take driving around for a little while untill computer relearns. Then let the car get cold and then start and see if it idles OK. Should idle at 1-1.2K and come down to 650 (I think). Do not touch the gas peddle before starting and untill it's at idle.

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Lifetime Member #116
Dave's '82

   

[QUOTE=xfire]...Don't throw parts at it! Find someone with a scanner to "read" what's going on...[/QUOTE]

Does the crossfire engines have a throttle position sensor (tps)??

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Corvettes and women are the same...You want to make love to them but they keep breaking down.

Yes,  the TPS is on the outside of the rear (driver side) throttle body.  Its a black rectangular piece about 2 inches long with three wires  going to it.