'82 turbo won't rev after changing plugs and fuel filter

[Over30S130]

Did a small tune-up since car was recently purchased and could not tell when tune-up had last been done and was also having some slight hesitation/surging/miss??? at normal throttle(fine under boost) and a low and slightly erratic idle. Here is what happened-changed the oil and filter, changed spark plugs to NGK copper U-grooves(gapped to .044)-same brand that was already in prior to tune-up-even indexed the plugs as best possible through trial and error-plug wire orientation verified as well. Changed the fuel filter and blew a little compressed air back through the line to the fuel pump to hopefully clear any possible blockages since fuel pump accasionaly had different sounds/tones at times. Took her off the ramps and started her up fine, but engine would not rev-period. It would sputter,bog, choke etc.-assuming running lean because I saw no black smoke. I disconnected the CHTS and she would FULL THROTTLE rev fine, but when RPMs came back down to idle, the engine would sometimes die and would not crank without re-connecting the CHTS. I thought the fuel pump might need priming, but then why would it rev fine with the CHTS disconnected. I even took all the new plugs back out to check and none of them were wet really. I went out and bought a new CHTS-although it looked slightly different, it looked more like what I had than any other sensor showing at the local auto store-O-Reiley's was the only one that had one or could even get one. The only difference was that the new one had a smaller/shorter part that goes in the head. It came with a washer which was installed-not sure if the brass part of the sensor needs to be directly in contact with the head as the old one had no washer. Started up fine-had better/near normal idle, but still would not rev at all without disconnecting again. I even cleaned the wire harness contacts with spray contact cleaner. I could drive like this I suppose, but I would have to feather the throttle at stop lights to keep from having it die on me and if it did I would probably need it reconnected just to get it started back up or I could leave it connected and not have any power whatsoever, neither of which sounded like viable options. Apparently the problem is not with the CHTS. What caused this change???????? Just wondering if anyone had any first hand ideas without having to go through the whole EFI Bible diagnostic check,

Edited March 5, 2011 by Over30S130

[Josh280z]

Did you check the timing chain??? because it may be loose.

[Over30S130]

Did you check the timing chain??? because it may be loose.

I havn't because it full throttle revs fine when I disconnect the CHTS-just may die or not keep an idle if remained disconnected. Cannot full throttle the gas from idle with it connected-justs bogs. New plugs were removed and looked OK-clean on one side-brown on the other with no black soot or wet look.

[Over30S130]

I havn't because it full throttle revs fine when I disconnect the CHTS-just may die or not keep an idle if remained disconnected. Cannot full throttle the gas from idle with it connected-justs bogs. New plugs were removed and looked OK-clean on one side-brown on the other with no black soot or wet look.

Very important update-I haven't driven my car in the past few days trying to research the CHTS. As mentioned earlier, I did a tune up and as soon as I let it off the ramps and cranked it, it would not full throttle up-it would only bog and pop through the AFM if I held the throttlr down long enough. If I disconnected the CHTS, it would rev fine, but would lose idle and stall and it would not restart without reconnecting the CHTS. I tried this morning to take a stab at diagnostics with a meter and my FSM. I checked both my old and new CHTS in ambient temp(supposed to check in controlled water) and both were reading about 4 ohms which was in spec with the book for a temp. between 20 degrees F and 68 degrees F-outside temp. was about 50 degrees. I then check at the connector and got nothing???? I proceeded to disconnect and reconnect the 3 connections at the ECM, but I wanted to check #23 to ground for the CHTS since I did not get a reading at the connector. My probes were not small enough to get into the connector-oh well, so much for that! Before reconnecting the battery, I disconnected the connector at the decelleration device,I forget the acronym at the moment. I did this because I was having idling issues before the tune up. I started her up and everthing is fine now. Idle is at 750RPM and revs full throttle with no problems and holds idle afterwards as well! Go figure. I have read it here before and now cannot reitterate it enough, on cars this old, it pays to disconnect and reconnect all connections-especially those that are prime targets and at the ECM. Take it from me, wiggling-disconnecting/reconnecting has solved two of my major problems with this car. Who knows-maybe disconnecting the battery might have helped as this usually works with machinery that I work with and it works for computers by re-booting. Bottom line, however it got fixed I do not know. I am just glad because it was starting to piss my wife off with the purchase of my new found toy of long ago. The only thing I can figure that might have contributed to this whole problem is bumping the connector for the CHTS while installing plugs. The connector itself is cracked and missing clip now, but seems to be making solid connection without. the boot to the connector has a tear, but connection and wires appear to be fine. Hope this helps someone who has this known problem(s) with these cars-I know I'm a happy camper right now!

[Over30S130]

I drove the car and it drives with no real issues. The idle is back down to 500. In my previous post, I did let it get up to normal operating temperature and the idle was holding at 750???? Atleast I am driving her again.

Edited March 10, 2011 by Over30S130