Please help with engine diaganosis!!
Please help with engine diaganosis!!
Ok here is what I have. A 96 TA LT1 with a full LE2(Lloyd Elliott) package. I has about 1500 miles on the setup(with stock bottom end at 76k). It has a 6 speed trans with a 411 rear(stock) and ALL LE2 necessary suporting mods. I have a ASM 58mm Throttle body. The engine dynoed at 397rwhp/358 rwtq. It is very clean and well taken care of and has run strong and pulled hard thus far.
Today I was getting on it in 1st and 2nd gear when at about 6000 rpm in 2nd gear(I usually run to 6200rpm) the engine felt like all the power got sucked out, the engine died and I coasted to a stop.
After a 2 hour wait for a tow truck and $98 bucks later, here it sits in my garage. The symptoms are below:
It does turn over and sounds like it fires a quick cylinder but almost immediatly the sound of ignition is over and it just turns over then. The sound when it does turn over sounds differnt then usual. It sounds like the timing may not be right. It's not as smooth as usual.
I do not hear any engine restrictions like a piston, conn rod, valvetrain-all in the engine sounds OK. ???? I have not checked yet but it sound like it's getting a bit of spark and fuel as it does fire a tiny bit at first crank.
With this said, here are my thoughts on the issue:
Possible bad opti?? Does anyone know of a good link/method to test all inputs/outputs?
Bad/intermittent coil or heat sync part?
Valvetrain issue? Broken spring, bend pushrod? Colapsed lifter??(would these cause a complete no start/run issue?).
Fuel pump complete issue(but I do smell fuel when I turn it over, and it does fire a tiny bit at first???
CPU issue? Tune issue??
Any thoughts or advise would be a great help.
Thanks
Today I was getting on it in 1st and 2nd gear when at about 6000 rpm in 2nd gear(I usually run to 6200rpm) the engine felt like all the power got sucked out, the engine died and I coasted to a stop.
After a 2 hour wait for a tow truck and $98 bucks later, here it sits in my garage. The symptoms are below:
It does turn over and sounds like it fires a quick cylinder but almost immediatly the sound of ignition is over and it just turns over then. The sound when it does turn over sounds differnt then usual. It sounds like the timing may not be right. It's not as smooth as usual.
I do not hear any engine restrictions like a piston, conn rod, valvetrain-all in the engine sounds OK. ???? I have not checked yet but it sound like it's getting a bit of spark and fuel as it does fire a tiny bit at first crank.
With this said, here are my thoughts on the issue:
Possible bad opti?? Does anyone know of a good link/method to test all inputs/outputs?
Bad/intermittent coil or heat sync part?
Valvetrain issue? Broken spring, bend pushrod? Colapsed lifter??(would these cause a complete no start/run issue?).
Fuel pump complete issue(but I do smell fuel when I turn it over, and it does fire a tiny bit at first???
CPU issue? Tune issue??
Any thoughts or advise would be a great help.
Thanks
Well my wife just got home and I was able to preform a "turn over" test from the engine bay. I did not hear the ign. firing noise that I heard before. I removed the coil wire from the opti and found a both situations when cranking the same. The cranking sound is the same with or without the coil wire on. I stuck a screwdriver in the coil plug(opti side)(comming from the coil)wire and checked for spark, I did not find any spark when held to ground. Does this test work for this type of coil? Could it be a bad coil? How do I test? An impedeance/res test? That would be a prefered low cost easy fix solution.
It deffinetly has fuel, it stunk up the garage. I probably need a new set of plug when this mess is over.
Shobox, is the rotor spinning a common thing? The opti I bought used with 2k miles on it. It looked new. Would you rule out a valve train issue? If it's an opti, that's not so bad and will give me a chance to put a new fluiddamper Harmonic balancer on it(the one thing I do not have yet). Which opti is best the Accell or the MSD?
Thanks again for your help.
It deffinetly has fuel, it stunk up the garage. I probably need a new set of plug when this mess is over.
Shobox, is the rotor spinning a common thing? The opti I bought used with 2k miles on it. It looked new. Would you rule out a valve train issue? If it's an opti, that's not so bad and will give me a chance to put a new fluiddamper Harmonic balancer on it(the one thing I do not have yet). Which opti is best the Accell or the MSD?
Thanks again for your help.
Last edited by RPWS6; Aug 3, 2008 at 11:13 PM. Reason: spelling
The rotors falling off is a problem, if the screws were not checked and some Loc-tite put on them. As far as "Which opti is best the Accell or the MSD?", the answer is neither - factory GM is the best.
Check it for codes.
Did you read the Opti dignosis thread "stickied" at the top of the forum topic listing?
Check it for codes.
Did you read the Opti dignosis thread "stickied" at the top of the forum topic listing?
You are the man!!!! I can't believe it, so simple!! I have been thinking about it today and the no spark at the coil, I thought if it's a coil it couldn't get much cheaper to fix! . When I got home tonight, I took a look and sure enough, a blow 10 amp ignition fuse. A .20 cent part certainly helps with the $98 tow fee. Not bad, I kept it under $100. So far?? I didn't really rev it or drive it, it was late and the wife was sleeping above the garage. The LE2 rumble is awesome but loud when reved!! Hopefully it doesn't blow again!Does anyone have any thoughts as to why the ignition fuse blew?
Camaro1fastZ28, did your's ever blow again after that? Did it blow under acceleration? Was the car on? Off?
Thanks to all for the info on the opti, I'll keep it in mind if I ever have it open. How often should the cap and rotor be replaced?
Thanks again for the great tips!
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