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

Opti gurus step inside.......

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Old Jan 5, 2010 | 05:18 PM
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Default Opti gurus step inside.......

I need some input on an opti issue I'm having guys.

I'll start from the beginning and try to briefly explain.

Several months back I installed a cam in my '96 vette. The car seemed to run pretty well after the install. So I took it to a dyno to check it out. Not good, it only made like 272 rwhp and peaked out at 4500 or so. Sooooo, I tear it back down to recheck all my steps. This included making sure the cam was degreed in correctly, check dots on crank and cam sprocket to make sure they were correct, spring seat pressure open pressure, pushrod length etc, etc, etc. All checked out ok. So I contributed the problem to the new GMPP opti I had installed during this swap. I put my old opti back on during this tear down and the car cranked and seemed to run fine. I drove it for a day then brought it home and parked it with intentions on returning to the same dyno to run it again the next day. The next day came I go out and attempt to crank the car. No dice! The engine would turn over but would not fire except for a brief spurt or clunk just as I released the ignition switch. Da@@! I tear it back down again then reassemble only this time it has another new GMPP opti on. The car starts fine runs the best it ever has. I drive it for a while bring it home, cut it off, take it to the dyno the next day and it pulls 333 rwhp/328 ft.lbs torque. Ok fine, I come back home cut the car off and don't attempt to crank it for about three days. That brings me to today. I go out to fire it up and guess what......it's doing the exact same thing all over again. No codes at all.

I have checked and rechecked everything I possibly can to no avail. Have any of you ever had or heard of anything like this?

Below are a couple of links to threads I have at CF if you care to read through them. One is extremely long the other one isn't bad. They are in the order as things have happened. The last one was started today.

Thanks for any suggestions that you may have.

Mike


http://forums.corvetteforum.com/c4-t...-problems.html


http://forums.corvetteforum.com/c4-t...-hates-me.html

http://forums.corvetteforum.com/c4-t...-hates-me.html
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Old Jan 5, 2010 | 06:14 PM
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Did you ever have the ICM and COIL tested?



Mike
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Old Jan 5, 2010 | 06:23 PM
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Originally Posted by aboatguy
Did you ever have the ICM and COIL tested?



Mike
I went to have my ICM tested and the machine was broken or no cable or something like that. I got a new one.

I have tried two different coils with no change.
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Old Jan 5, 2010 | 07:03 PM
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Did you check the cam dowel pin length? How is the short jumper harness on the opti? Any green on the terminals?
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Old Jan 5, 2010 | 07:07 PM
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Originally Posted by flame
Did you check the cam dowel pin length? How is the short jumper harness on the opti? Any green on the terminals?
I did check the pin and it was within spec. Green on the terminals? Inside the opti? I did remove the cover on one of them but I really don't recall if there was any green on them. If there was what would the cause of that be?
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Old Jan 5, 2010 | 07:19 PM
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Originally Posted by Weav's Vet
I did check the pin and it was within spec. Green on the terminals? Inside the opti? I did remove the cover on one of them but I really don't recall if there was any green on them. If there was what would the cause of that be?
Probably talking about corrosion
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Old Jan 5, 2010 | 07:20 PM
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I'm talking about the female terminals in the opti jumper harness. Take it off and have a look at them. Its common for them to get corroded over time.
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Old Jan 5, 2010 | 08:05 PM
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opti harness needs close inspection.very well could be the dreaded green on terminals of connection.
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Old Jan 5, 2010 | 10:40 PM
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Originally Posted by flame
I'm talking about the female terminals in the opti jumper harness. Take it off and have a look at them. Its common for them to get corroded over time.
Ok, thanks. It's a new harness but I will take a look at it.

What causes this "Green Terminal Disease"? Better yet, how do you fix it? Also, does this mean the opti is toast once again?
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Old Jan 6, 2010 | 06:08 AM
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Went out this morning a pulled the harness off of the opti. It looks completely normal, no sign of anything green on either end.
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Old Jan 6, 2010 | 11:25 AM
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I'm fresh out of ideas then
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