DirtyDaveW

Readers digest version:
"Bought one of the first LTCC kits with the individual long wires to each coil in 2003. Fired up first time. Then when motor went out in 2004(oil pump drive gear sheared off all teeth), I sold that LTCC kit to a fellow Fbud, vowing to buy another LTCC when the engine was rebuilt. Bought the next LTCC kit in 2008 with the integrated wiring. It utilizes the stock LS1 wiring harness. It didn't work, car ran like crap, backfired, gas fouled plugs. Gave up after month of trying and went back to stock OPTISPARK."


Fast forward to last night, since I'd torn a spark plug wire off the stock Opti, I decided to re-install the LTCC. Hooked it all up and tried to start. Same crap as 2008. FML.... Checked all connectors and all seemed to be well. Cussed and went out to dinner with the wife. As I'm driving to the restaurant, a thought popped in my head.... "How do I know if the LS1 coil harness is oriented 1,3,5 and 7 on the drivers side? If I have it *upside* down from stock it would be backwards. But, how can I tell if it's rightside up? It's not marked with *this side up*, etc." So I went out this morning and flipped the coil pack assembly over and plugged the plug wires into each coil. I tried to start it but it was still running like crap, flooding. Dammit!! I thought, how can I decide if each side is correct?", then the next thought came to me. "Pull out the plug from cylinder one, put the plug on it's plug wire on the fender so you can see when it sparks, then stick a finger over the plug hole in the cylinder and crank it. When the cylinder pushes the air out of the cylinder with the most force, it should be a compression stroke. At that time, the spark on the spark plug should occur. If it's NOT timed with that, it must be oriented backwards.". I pulled the injector fuse out so no fuel would be there in the other cylinders, turned on the ignition key, then attached my remote starter , pulled the #1 spark plug, installed it in the wire, grounded it so it would spark when it got the charge, put my left finger over the plug hole and pressed the remote starter. Aha! It IS on there backwards. I reversed the wires, the put the plug back in, it's plug wire on and moved over to cylinder #2(first cylinder on the passenger side of the motor). Same thing, it was backwards. After putting everything in place and securing it all, I got in the car, said a small prayer and turned the key to 'start'.VROOM! She started right up and ran smoother than ever.


In the preliminary 'readers digest' version, I didn't go into the sordid details of what all I did when trying to figure out why it ran like crap initially in 2008. Apparently the whole time, the coils were, by accident backwards, when I tried the LS1 factory harness. So no matter what I did, it still ran like crap because the issue was ALWAYS the coils were firing out of order.

• Sent LTCC back to Bob Bailey, telling him it wasn't firing correctly. He put it on his test mule and it ran fine. Sent it back to me, no charge.
• replaced injectors (thought one or more was clogged)
• replaced coils (thought one or more was bad)
• Went thru 30 different PCM Tune settings trying to get it to stop flooding. Of course nothing helped
• Bought a new engine compartment wiring harness(thought I had a short)
• Bought a new GM Optispark(thinking the new Jegs opti was faulty)
• Took timing cover off and verfied cam timing was correct, introducing a nice oil leak at the oil pan/timing cover in the process.
• Sent LTCC to a bud of mine in Austin that has a working LTCC. Asked him to put my box in place of his to see if it ran. It ran perfectly.
• Sent LTCC and LTCC harness to Bob Bailey, thinking it must be the harness. It worked fine. Bob Sent it back, no charge.

When I decided to just forego the LTCC and use the regular Optispark, it ran fine.

I had unintentionally installed the coil harness unside down (since I hadn't thought about that aspect) by installing it for conveniences sake, trying to put it where it was least visible to the visitors eyes. I feel like such a fool for not recognizing this issue back in 2008.

Just sharing here so that if someone else decides to use the stock LS1 harness, they establish which way the harness or plug wires must go before they try to fire it up.