Douglas3735

Hi all! I just recently installed a ls6 out of a 03 z06 in my 73 z38. I ran the stock drive by wire, went with a walbro 255 fuel pump, reprogram my PCM, and running a t56 out of a 00 camaro. I got car started and sounds great but when I go take it for a test run, the car will run good for the quarter mile but then engine will not let me go pass 3500 rpm. As soon as I turn igition off. Then turn back on, I'm good for another couple hundred feet. The further I go the less power I'm receiving. Anyone have any suggestion? Thank you!

bczee

iTrader: (12)

Can only suggest you get a scanner and monitor the sensors..

Check all of the connectors and wires of the sensors..

Fuel pressure or good battery/alternator voltage ?

Check the Ground or add some !

Vacumn leaks ?

Douglas3735

Thanks! I'll check those. Any other suggestions will be very appreciated!

chuckd71

iTrader: (23)

Do you have fuel pressure and voltage gauges? My car did something similar and it turned out the alternator was bad and the engine was basically running on battery only, so I got a new alternator and everything is okay.

Douglas3735

I have a battery gauge but not a fuel pressure gauge. Battery still looks good.

ls68firebird

was there a "valet" option in the original computer? perhaps that didn't get turned off. not sure how that part works. just thinking out loud

ls1nova71

iTrader: (4)

Are you getting 100% throttle body opening? Are you using the TAC and pedal from the Z06? Have somebody press the throttle and watch the throttle body and make sure it's working correctly. Other than that, like others have said, put a scanner on it and see if there are any codes.

Douglas3735

Yes. I'm using the tac and pedal from a z06. I did have some1 press on the gas while I checked out the throttle and it does open all the way.

chuckd71

iTrader: (23)

My battery was showing 12v while running, and that was low enough to make the fuel pump angry. Might want to check your fuel pressure (it would be a good gauge to have anyway for a swap, IMO).

Douglas3735

Thanks! I'm gonna Try to get one this week. I'll let u know of it works out.

Douglas3735

Ok. I just found out when I go slow in first gear I can climb all the way til I redline but as soon as I punch it or go full throttle, that's when it falls on it's face.. Any suggestion??

zipster

iTrader: (5)

traction control? Torque management?
I did a stroker build on a 2001 Cobra Mustang, it was also getting 17 lbs of boost. Well, during the test runs, it would run great, idle perfectly, when ever you floored it, I would get a random misfire code. It was the traction control trying to prevent tire spin, well with 612 rwhp, it was having a difficult time. turned off the traction control button, and no misfire.

Douglas3735

One more thing, I just jack the rear end up then tried banging all gear and it work great! So it's only happening when there is a load on the car..

racerfox

iTrader: (4)

Fuel pressure!!!

Douglas3735

Let me call the shop to see if they turned those off.

Douglas3735

Wow!! You guys are right!! It's my fuel pressure! It idles at 58lbs but as soon as I punch it, it drop from 58lbs all the way to 20lbs! I don't know what I'm doin wrong. Ran with a walbro 255, 3/8 fuel line, stock fuel filter. All brand new too! Am I doin something wrong?

Douglas3735

Ok. I finally fix the problem. I want to thank every1 one here for your help. I really do appreciate it! Thanks again..

bczee

iTrader: (12)

Glad we could help out. but l.. what was the Fix ?

Douglas3735

Oh sorry, it was my fuel pump. I switched it to a used Bosch fuel pump I had laying around and it worked great! I think I got a defected walbro so gonna call to see of I could get a refund or exchange.