ModernMuscleCars.net - Modern Muscle Cars Archive

Pages: 1

LS1 problem..need help!
(Click here to view the original thread with full colors/images)

Posted by: CHAMPLS1

Having a problem with my 01TA..It runs great during normal operation.. At WOT close to 4900rpm it feels like the car is running out of feul but picks up and pulls on to the shift point well(around 5900)? noticeible in 2nd and 3rd gears...I noticed the poblem after installing Mac headers and off road Y-pipe although I never really drove the car hard for a whie before the headers so it could have been happening for quite some time.I checked the feul pressure, fuel filter, changed plugs, added octane boost...still no luck. also if I give the car hell 1st through 3rd gears a few times in a row the SES light will blink on and off serveral times then go away..The plugs where a reddish color. Meaning a lean condition if im not mistaken? I have had a stock ported MAF sensor on the car and it has ran fine. Im thinking it could be the problem making the car lean out on the top end? Has anyone had any similar experinces?Any info could help

Posted by: Penske

The reddish color on the plugs is probably from the octane boost.

There's an oxygen sensor in the headers, isn't there? Might check that out.

Posted by: RCowan99SSConv

What they said.. also check for air leaks around your EGR and AIR tube connections as well as where the Y-pipe bolts to the headers. When the SES comes on and stays on its usually a minor problem... When it comes on and blinks at you that means its serious and you need to pull over! If a bad O2 or no Simms is leaning you out, you may be getting some dangerous detonation. Like Evil said, get Autotap on there to find out what it is. It will save the code that was set.

Posted by: StoneFox

A blinking check engine light is a non random cylinder misfire. Could be a bad coil or fuel injector.

Posted by: CHAMPLS1

I hooked the OBDII scanner up today and pulled 2 codes-left bank lean and right bank lean . The O2 sims work fine and im sure the pre cat O2 sensors where not damaged the AIR tubes are no leaking. Ive herd the ported MAF can cause a lean condition? Can this be fixe with a MAF translator?

Posted by: cswrench

If you are setting lean codes make sure you do not have an air leak. or a vacuum leak. Air leaks between the maf sensor and the throttle body will set lean dtc's. A flashing ses lamp is a catylist damaging missfire. and you are supposed to stop operation in that area untill repairs are made. another thing is make sure all plug wires are on or not burned on the new headders. I have had LS1's set lean codes with burned/loose plug wires. The reddish color is from the dye in the fuel and or octane boost you are running.

Posted by: CHAMPLS1

The wires are far enough away they arent being burned..Also no air leaks between the MAF and the TB the thing is brand new...No exhaust leaks either

Posted by: Bird of prey

With long tube headers and High flow cats on my x-mas list I hope I don't run into the same issues. My 2000 T/A is basically stock, a lid with K&N and a cat back.
Have you looked at the timing as a source for your problem.

Posted by: Bird of prey

Damn was my question that stupid?

Posted by: RCowan99SSConv

[quote:fc26234908="CHAMPLS1"] Ive herd the ported MAF can cause a lean condition? Can this be fixe with a MAF translator?[/quote:fc26234908]

Yes, if you port the MAF it WILL run leaner. If its ported a LOT, it will be more than the Ltrims and Strims can compensate for. The computer can add back 25% with the Ltrims (long term fuel trim) and an additional on-demand 25% with the Strims (short term fuel trim). But if you have a seriously ported MAF it may be more than the system can handle. A MAF translator can solve your problem. You want to dial it in so that your Ltrims are near Zero. The more the computer has to "react" by adding/removing fuel the less optimal it will be. Having them close to zero, the computer is already 'dialed in' and doesn't have to make major fuel delivery changes on-the-fly.

So you may be asking why does anybody port a MAF if the computer will just compensate for the change? That's because at WOT the Strims freeze at what value they were just before WOT. So if you port it you can maintain the lean condition during WOT which seems to give some people some gains (slight porting over stock).
If you have Negative Ltrims (computer removing fuel) right before WOT then it sets the Ltrims to Zero by default. A lot of people like to tune for slightly negative ltrims (slightly rich) in order to force the computer to lean slightly at WOT.

Posted by: CHAMPLS1

Thanks for all the replies guys. Im still having the problem...I put a stock MAF sensor with screen on the car and drove it for a couple of days , and still no luck. My buddy said I may need to get a program such as LS1 edit to fix the problem. I also got another question...In the GM HighTech I seen a sunset orange 01TA and in the pictures I didnt see any AIR tubes where they should be on the headers. Can I remove the smog pump on my TA, and cap off the AIR tubes on the headers? Also I got a MAF translator off ebay that should arive this week. Do you think the MAF translator will solve the lean condition? Wont the car be rich throughout te RPM band?again thanks for any help.CHAMP

Back to the Forums