We have spent the past three weekends tearing down 99RagtopSS's car.

Weekend #1 consisted of the teardown.

Weekend #2 was motor build-up (while we waited for the Grot headers to show up...) including just about everything you can think of... basically, the only thing stock in that motor anymore is the crank, pistons and block. We didn't take the motor out of the car. Ed Wright reprogrammed the computer.

Weekend #3 (today) ... the Grots are here, they get installed, and the final phase of buttoning up the rest of the car.

Now for the problem...

We started the car up. It turned over - no problem whatsoever, and found a rock-solid idle. Oil pressure, voltage, etc... all gauges read normal. We let it idle, made sure the radiator was full, coolant had burped itself out, all was well. It idled for ten minutes without missing a beat. So, we shut the car off.

About five minutes later, we tried to start it again. It cranked and didn't kick over. It cranked some more... then, after about ten seconds of cranking, it started. And found idle... and idled just fine. I noticed that the exhaust was a little blacker than normal, and smelled of gas... but I just attributed that to the computer not being quite "learned" of the motor's drastic changes yet. So we called it a night.

Later that night, Jeff took the car out for a test drive. It was running like it had absolutely no power under throttle. When he gave it gas, it felt more like a weak 4-banger than a built LS1.

I haven't had a chance to pour over the motor with him yet... but I've gone over it in my head a thousand times trying to think if there's a sensor or connector left off that would have made the car go into limp mode... but I was almost positive we hadn't.

Moral of the story... I need suggestions for where to start looking for the source of such a power-dimishing problem. I'm so exhausted from the 12-hour marathons we've put on from working to build this car up that I can't think straight, and you guys are the best source for ideas of where to start looking.

After I have a chance to look it over tomorrow with Jeff, I'll post up... but please... any and all ideas of what to look for would be appreciated...

 

No SES lights?

You guys don't have an autotap or a scan master?

Good luck and I hope it's something simple.

 

A couple things based on what I've read before:

1. Idle relearn procedure.
2. Burnt wiring from the headers.

Either could be the culprit.

 

Bad ground?

 

Ahhh... yes, sorry... there is an SES light that came on during the short test drive.

No, we don't have Autotap or a Scanmaster handy.

I was going to check the plug wires first thing, and the ground on the driver's side head might be loose as we had to loosen it and turn the eyelet to get extra slack in the cable for the injector connectors... so I plan on trying to tighten it more.

 

Just a thought, but maybe it is one of the o2 sensors, check for burnt wires, pull the o2 and see if it is running pig rich, could be a leak in the header allowing air in, so just check those things, I had a similar problem, but mine was bad gas which caused the o2's to go hay wire and it went rich bad, just a sugestion

JET