crazyd Posted November 10, 2011 Report Share Posted November 10, 2011 (edited) My '92 GTP refused to start after I pulled into a parking lot last night. I'd driven it there with no problems other than it being low on power and getting the "chuggles" if I tried to get more out of it, but only between 2000-4000rpm. Once past that point, though it didn't feel like it was all there, it did pull smoothly. I first noticed it on Sunday, and had decided it was probably just a clogged fuel filter (which I haven't changed for about 30k miles). Planned to do it today, but I tested the fuel pressure and it was at 41psi and holding, so I didn't think it was urgent. The only other symptom is it sounds really odd when I'm cranking it, a little slower than usual and without the normal tun-tun-tun sound, which deteriorates into this continuous swishing sound the longer I crank it. I can't accurately describe it so I've uploaded a youtube vid here. [video=youtube;KxKgITAJd3Q] This also started several days ago before it completely refused to start, so I don't think anything catastrophic has failed. Here's what else I've checked: Suspected TPS, so I pulled codes. 6 #12's and nothing else, so the ECM seems to think everything's hunky-dory. Inspected vacuum lines. Did this while the engine was running and no disconnections or hissing noises noted. Pulled timing belt inspection cover, belt is tight and like new (replaced about 20k miles ago), appears clean inside, no "hairs" Inspected plug wires and ensured they are all seated properly Oil is clean, 10W-30 synthetic, no coolant contamination Exhaust is clean, no smoke or funny odor; cat replaced about 10k miles ago Replaced ignition coils & ICM I don't think that the timing chain broke, I think I replaced it at the last rebuild about 20k miles ago and it wouldn't break just from shutting the car off. I have a fuel pump activation switch on the dash, and I know the fuel pump is running and pressurizing to 41psi at the injector rail. Anybody got any other ideas? Edited November 10, 2011 by crazyd Quote Link to comment Share on other sites More sharing options...
slick Posted November 10, 2011 Report Share Posted November 10, 2011 Have you verified spark? Quote Link to comment Share on other sites More sharing options...
Addicted To Boost Posted November 10, 2011 Report Share Posted November 10, 2011 Have you verified spark? Agreed. Start by checking spark and checking your crank position sensor. Quote Link to comment Share on other sites More sharing options...
crazyd Posted November 10, 2011 Author Report Share Posted November 10, 2011 I figured by replacing the ICM and all three ignition coils that I would be factoring spark out of the equation... But the CPS is an interesting possible culprit. How would I check it? Quote Link to comment Share on other sites More sharing options...
jman093 Posted November 10, 2011 Report Share Posted November 10, 2011 I figured by replacing the ICM and all three ignition coils that I would be factoring spark out of the equation... But the CPS is an interesting possible culprit. How would I check it? Checking for spark as mentioned is the best way to start. Quote Link to comment Share on other sites More sharing options...
White93z34 Posted November 10, 2011 Report Share Posted November 10, 2011 (edited) make sure you have spark and injector pulse. ediiit.... Actually after watching that video I would verify that the cams are being turned, sounds like it could be a failed belt or chain, Edited November 10, 2011 by White93z34 Quote Link to comment Share on other sites More sharing options...
crazyd Posted November 10, 2011 Author Report Share Posted November 10, 2011 Belt's OK. Just replaced the CPS but it had no effect. 1-man job, so checking for spark isn't really possible. Quote Link to comment Share on other sites More sharing options...
crazyd Posted November 10, 2011 Author Report Share Posted November 10, 2011 Yeah, the timing belt isn't moving. Little soon for a timing belt to go after only 20k, but no big deal to replace it again. Got a new CPS, ICM and coils in the process. Quote Link to comment Share on other sites More sharing options...
GOT2B GM Posted November 11, 2011 Report Share Posted November 11, 2011 failed timing belt tensioner? Quote Link to comment Share on other sites More sharing options...
White93z34 Posted November 11, 2011 Report Share Posted November 11, 2011 I'll put money on it. Quote Link to comment Share on other sites More sharing options...
crazyd Posted November 11, 2011 Author Report Share Posted November 11, 2011 If it is, I've got lots of 'em... Quote Link to comment Share on other sites More sharing options...
White93z34 Posted November 11, 2011 Report Share Posted November 11, 2011 make sure you refill any replacement tensioner with 5w30 synthetic oil per the service manual. Quote Link to comment Share on other sites More sharing options...
Galaxie500XL Posted November 11, 2011 Report Share Posted November 11, 2011 On my LQ1, the failure wasn't the tensioner, but one of the idler pulley bearings. It got hot, and melted the plastic idler pulley... You might want to consider replacing them while you have things apart...when I did my last timing belt, I replaced EVERYTHING. Quote Link to comment Share on other sites More sharing options...
White93z34 Posted November 11, 2011 Report Share Posted November 11, 2011 ^ always good practice to replace it all. Its more expensive but common sense IMO. The tensioner actuator is something often overlooked since not a single belt kit comes with it... dealer only item Quote Link to comment Share on other sites More sharing options...
Galaxie500XL Posted November 11, 2011 Report Share Posted November 11, 2011 True...I think I paid $125.00 for a new actuator...the hard part was getting a replacement mounting plate for the tensioner..not many left, but I figured it made sense, since I didn't know the history of the car to start out all new. The plate was I think less than $7.00. I saved all the old parts, just in case. Quote Link to comment Share on other sites More sharing options...
crazyd Posted November 15, 2011 Author Report Share Posted November 15, 2011 (edited) Got the car back on the road last night. No idea why the belt lost tension, the actuator seemed to work just fine though it had no oil in it. Replaced it anyway. Pulley bearings were all tight as a nun's butt. Edited November 15, 2011 by crazyd Added picture Quote Link to comment Share on other sites More sharing options...
GOT2B GM Posted November 15, 2011 Report Share Posted November 15, 2011 Glad to hear you got it sorted Quote Link to comment Share on other sites More sharing options...
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