Bird1995

So hello all. This will be my first post on ls1tech. Great place ya have here. I just bought a 95 T/A recently at a used car dealership. At test drive it ran great. Could not have ran better. They sent it for inspection and it came back after 2 weeks running like absolute crap. I finally decided last weekend I would make time to bust my knuckles. Plugs, wires, opti, trans mount (auto), cleaning up the intake. 8 and a half hours later, I pulled out and the car decided to go sideways at a half a pedal. Pretty damn happy with the results of my labor and repeated crap in both eyes and the broken off plugs. So today, I was cruising thru town on a one block section they have been working on for over a year. By far the worst assphult driving condition ever, hands down. At the end of the block, bouncing and shaking like I was rock climbing, the car began to run like it did prior to tune up . Let me explain how bad it was. 1 wire burnt completly off from the headers, which I overlooked until the day I did the tune up, next wire over snapped off when I pulled it. The plugs were gapped odd, some at 35, some at 40, some at 45. The car now runs like it did with that setup. No power, putting and such. Feels like a 4 cyl. Need suggestions/help before it finishes driving me nuts. No wires seem to be loose, opti is dry and clean, wires tucked so no contact with headers. No visible damage. Not sure if this may help, LT1 swap from a 96 Z-28, aluminum heads, custom cold air intake, no cat, bullet muffler. No leaks on exhaust or intake. CPU swap from the same 96 Z-28. Can't think of any other mods that may effect the performance, especially all of a sudden. Thanks in advace.

lemons12

iTrader: (71)

Long shot but often a problem... o2s.

Bird1995

O2, good. Backfireing as I neglected to mention in OP. Running rich. Changed fuel filter and ran Seafoam and a half a tank of gas. Pulled the vaccum line from the intake and left it suck some Seafoam into it. Backfire has reduced slightly, motor starting to run slightly smoother. But still same deal. Left a friend drive it today. He has a 350 small block for a heart and it pumps 94 octane thru his veins. He said it is running great but also said check O2, possible burnt valve and check fuel injectors. It still seems to me that it is in the ignition. I did not change the coil pack with the tune up and I mentioned opti in my OP, not sure why but I did not change it. Opti and coil is my next best guess? but why would it convert back to pre-tune up performance? For that one week it would do 0-60 in 4 seconds and now it takes about 10 at full throttle. Should I finish out the ignition system or go onto fuel? The price of an Opti is just plain terrible.

lemons12

iTrader: (71)

My next assumption would be opti.. However I know ls1s, someone more enlightened on lt1 problems should chime in.

Bird1995

It's killing me, maybe the car too. Opti is next but I just got laid off last friday. No return. On a side not, my heater vents broke, 2 of them. I don't use heat or a/c and was thinking a gauge would go well there. Anyone ever put a gauge there? what size/customizations are needed?

lemons12

iTrader: (71)

Yes sir, there are write ups all over the board for it.

babbage1109

iTrader: (11)

You will probably have better luck posting in the lt1 section Good luck

transamtom

iTrader: (8)

Do you still have the EGR hooked up?

That would be my guess or a vacuum leak.

Gojira94

iTrader: (4)

Try reseating the plug wires at the opti and plugs, and burp the boots so they don't back off. You need to put a little dab of dielectric grease in the ends of the boots if you didn't before. All that vibration, immediately followed by running like crap sounds like a loose wire or three, even though they wires look to be on tight.

Also, after doing this, run it at night with the hood open and look for arcs from the opti or plug boots. What king of wires did you use? what plugs and what gap? What brand opti? It's unlikely that would go again unless it was crap quality.