LT1-LT4 Modifications 1993-97 Gen II Small Block V8

Need some help with this one...car left me stranded!!

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Old Jun 22, 2007 | 10:27 AM
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Exclamation Need some help with this one...car left me stranded!!

New LT1 owner here...I have a '97 Z28...A4 with 137,000 on the clock that I bought on 6/1/2007. Driving home from work yesterday I got on the throttle (full throttle) to pass a truck on the interstate. I was doing about 55, so she kicked down to 2nd...and then proceeded to stall. I threw it in Neutral and hit the key, but all it did was turn over...no restart. I coasted to an off-ramp, and tried restarting again after I got it on the shoulder. It would start, but run very poorly and no higher than about 200 rpm (yes, 200, not 2,000). I got it towed home and still does the same. I've called a few dealers, but can't get one consistent answer...a couple of guys at work told me it may have jumped time but the dealers said that's not likely. I'm really hoping this is just a clogged fuel line or something simple like a bad ICM connector. I haven't done anything to it yet...I'm saving that for tomorrow afternoon.

ANY comments that may point me in the right direction would help!!! Thanks in advance!
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Old Jun 22, 2007 | 11:53 AM
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i dunno if you know if your fuel filter's ever been changed check it and then check fuel pressure. but im almost sure its your opti spark.
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Old Jun 22, 2007 | 12:05 PM
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If the ICM was out, it wouldn't start at all. Jumping a tooth on the timing set is doubtful.

Have you checked the basics? Spark, Fuel, and air? Is the car throwing any codes? How is it acting when you try to start it (backfiring, sluggish rotation, ect)? DO NOT just start throwing parts at the car until you've got a relatively good idea what the problem is. You'll just throw money away like that.
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Old Jun 22, 2007 | 02:02 PM
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Originally Posted by Fastbird93
If the ICM was out, it wouldn't start at all. Jumping a tooth on the timing set is doubtful.

Have you checked the basics? Spark, Fuel, and air? Is the car throwing any codes? How is it acting when you try to start it (backfiring, sluggish rotation, ect)? DO NOT just start throwing parts at the car until you've got a relatively good idea what the problem is. You'll just throw money away like that.
I agree with both of the previous comments, do some checking before you buy stuff. I would not think jumping a tooth would stall the motor, I figured that it cause worse problems.
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Old Jun 22, 2007 | 02:25 PM
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I wasn't really aware ours could "jump a tooth" as it were. Interesting... I like info

And +2 for checking the basics. Fuel pressure is a good start. Were you low on fuel when you punched it? It could've sucked a bunch of ***** into the filter and clogged it up nice and tight. I had a Suburban that somehow still ran "fine", and yet I couldn't blow through the filter with all my might. Unless you know it's been done recently, that's one of the first things for maintenance to be changed. It's probably one of the most neglected parts. One guy on here said his car really woke up after changing it. He cut it open and showed us pics, it wasn't pretty.
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Old Jun 22, 2007 | 09:43 PM
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I replaced the fuel filter a couple of weeks ago, and when I floored it to pass that truck, I had a full tank of 93 Octane. The fuel pressure check is one of the top things on my list. It is not throwing any codes at all...when it's running, the SES light is on, but when I scan it with my OBDII, it proudly displays "NO CODES" across the screen...WTF? I have changed the driver's side plugs and wires...pass. side are still original, but that's going to change this weekend, no matter if i have to break my arm in 7 places to do it!! When I start it, the starter turns over strong, and the car doesn't try to run until I release the key. When it's running (at 200 RPM), giving it gas does nothing, and I really couldn't hear any backfires.
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Old Jun 22, 2007 | 10:27 PM
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PCM dead, Security issue?
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Old Jun 23, 2007 | 10:54 AM
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The PCM is another thing to consider...if it was a security issue, would it even start at all? The security light is not on when it is running. I've got the negative cable off right now...plan to let it sit for about 30 mins...give the computer a chance to reset...might not help but surely it won't hurt.
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Old Jun 23, 2007 | 02:48 PM
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Originally Posted by Formula350
PCM dead, Security issue?
It wouldn't start at all with either of those issues.

If you check fuel pressure and it's good, then I'm going to say it's very likely the optispark.

Check spark from the coil to the opti, and from the opti to the plugs, etc.
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Old Jun 23, 2007 | 02:58 PM
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sounds kinda like my opti when it went out
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Old Jun 24, 2007 | 02:38 AM
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I helped put the 4 pass. side plugs/wires and nothing improved. The owner and I are pretty sure it's the opti, but will have someone take a look before any major "projects" are undertaken.
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Old Jun 24, 2007 | 12:39 PM
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Check fuel and fire. If you have fire going into the opti but not out rotor is usually dead
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Old Jun 25, 2007 | 12:14 PM
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yep...me an ol' Dubya swapped out the pass. side plugs and wires... fuel pressure is 41PSI...no change...went to an undisclosed garage behind an undisclosed tow truck to use the engine diagnostic computer...I couldn't make heads or tails of it. I got pissed. I said the heck with it and had the undisclosed tow truck haul it to the repair shop...in short...i didn't feel like messing with the Opti...this is my daily driver and i need it running...SOON!!
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Old Jun 25, 2007 | 07:24 PM
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Did you check nothing got stuck in the air intake just before you floored it?, plastic bag floating around the road sucked into the intake would starve the car of all air.

Sara Lou
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Old Jun 27, 2007 | 08:43 AM
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I checked the TB as one of my first things...no plastic bag, dead cat, etc. I called the shop and the tech told me that he couldn't get 12 volts at the computer, but the battery was producing 12 volts. He said that he was going to try replacing the positive cable and see if that helps.


Uhhhhh....OK...?
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Old Jun 27, 2007 | 10:08 AM
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Try checking the egr valve it may be stuck...it would run like crap if it is. A tech1 or a tech2 can do a cycle test to see if it is working or not, just a thought for ya.
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Old Jun 27, 2007 | 12:39 PM
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sounds similar to when my opti was going out until it finally went out with a loud POP. pretty expensive piece to change if you dont know for sure though. good luck
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Old Jun 27, 2007 | 02:38 PM
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Kind of useless to come onto the forum, ask for help, change 4 spark plugs and then send it to a shop. Have fun getting raped. You do realize if the + cable was bad, the starter would just click or do nothing at all. If the computer wasn't getting any voltage, the car wouldn't try to run. Sounds like you stumbled onto a incompetent mechanic who is going to throw parts at the car until something works, at your expense. There are checks for just about everything. With a little more patience, we may have been able to pin point the problem. Good luck.

P.S. An opti change can be done in a 1/2 a day by a semi-skilled mechanic. Someone that's done them before can have it done in less than 2 hrs.
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Old Jun 27, 2007 | 02:58 PM
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Originally Posted by Sweetred95ta
Kind of useless to come onto the forum, ask for help, change 4 spark plugs and then send it to a shop. Have fun getting raped. You do realize if the + cable was bad, the starter would just click or do nothing at all. If the computer wasn't getting any voltage, the car wouldn't try to run. Sounds like you stumbled onto a incompetent mechanic who is going to throw parts at the car until something works, at your expense. There are checks for just about everything. With a little more patience, we may have been able to pin point the problem. Good luck.

P.S. An opti change can be done in a 1/2 a day by a semi-skilled mechanic. Someone that's done them before can have it done in less than 2 hrs.

agreed. about 3 months after I first got my car the opti when out. coincidentally right after my MSD ignition was put in. I knew just enough to put that ignition in but nothing about the opti. took it to a shop and they threw parts at it and gave it back to me "fixed". it had the same problem, stumbling over 2200rpms and would refuse to shift up. after me telling the mechanic numerous time i thought it might be the distributor/optispark he finally put one in and taadaa all fixed.... that sadly was also a $2k bill or about that.

summary, watch out and dont get raped as I did.
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Old Jul 6, 2007 | 09:28 AM
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well thanks for the advice, guys. The little mom-and-pop shop that I took it to couldn't figure out what was wrong with it, even after a week. They did, however, manage to royally F-up the paint on the front bumper cover...it was already chipped on the driver's side, but now from the lower inside corner of the driver's side headlight opening straight down and back to the previous chipping is all flaking off. There is a white scuff on it, and my driver's side fog light got smashed up real nice. I'm guessing they ran it into something or somathing backed into it. Also, my rear spoiler is cracked real nice over the third brakelight...somebody tried to push a 3,400 pound car with a piece of fiberglass!!!! This is probably why the guy didn't charge me a dime for the week stay, but he is buying (and installing) a new fog light. I'm not too worried about the bumper b/c of the previous damage, but I'm a little pissed about the spoiler.

I had it towed from there to the local dealer...bend over and grab ankles for this one. Surprise surprise it was the Opti...tax and everything was $1,034.81. Ouch. Guess I should have gotten off my tail and done it myself, but you live and you learn...the Opti itself was $542...Labor $360...coolant $18.50...and gaskets $1.50..the rest is tax. But at least now it's fixed.
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