Carbureted LSX forum - help

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I have posted on here alot and got alot of good info so time to get this one fixed.

I just built a new bottom end and put my heads on it with a new cam and super vic intake

We just got it off the dyno Thursday and dropped it in. Ran great on the dyno using my MSD box, Coils, Wiring harness, sensors and carb. Dropped it in car and from the very first pass it will start stumbling really bad about 5600-5900. Just does not want to pull past that. Any ideas what to check? Just spinning the motor over in park it revs to 7000. So its when it has a load on it. (burn out and going down track) It will make a pretty good pass as long as u shift it about 5300.

LS
Hyd cam
supper vic intake
6LS msd box
Pro systems carb

We changed MSD box , coils , carb, ran new power and ground wires from battery to box and check fuel pressure.

My carb on the dyno was going lean in the upper RPMs but still pulled to 6900. I put a diff carb on it while at the track and same thing.

Its not the best vid had to hold phone drive and shift. This was just pulling out on the street and getting on it. It will do it that quick everytime. Keep it below that rpm and it runs great. Stumble is at .16-17 in the vid

starts at 5500 RPMs

http://www.youtube.com/watch?v=NHcKu...wPTcNONodbD5Xh

Just a shot in the dark, but sounds fuel related. The engine dyno didnt use the fuel delivery system in your car and g-forces dont come into play on the engine dyno. Do you have a way to monitor fuel pressure going down the road?

:metoo: . I would also lean towards fuel. Have you shut it down after a pass and checked a plug? That would be a good place to check as well. Eric L

Just a shot in the dark, but sounds fuel related. The engine dyno didnt use the fuel delivery system in your car and g-forces dont come into play on the engine dyno. Do you have a way to monitor fuel pressure going down the road?

Yes pressure was at 6 1/2 to 7#s the whole pass.