nevasuma

iTrader: (1)

Here is what I have, ls2 out of a 2006 in my 78 trans am with t56. I am running a qft hr-780-vs carb, with holley sniper gas tank with fuel pump in tank. I have a automotive dual stage fuel pump regulator knocking the pressure first done to 12 psi and then down to 6.5 psi for the carb. My ignition is msd 6014 box. Timing starting at 15 and going to 28 all in by 1500 rpm.
here is my problem. The car will not run right. I have the idle circuit good with afr in the 13's. But anything after 1/3 throttle under load the car breaks up, bogs, backfires and sometimes stalls. Seems like it is going lean. Not sure if it's carb tuning or fuel starvation.
thanks for any help!!

speedtigger

iTrader: (16)

Is this only at light part throttle or does it do this regardless of RPM and throttle position? Does it do this if you light into it with WOT at higher RPMs too?

nevasuma

iTrader: (1)

I changed the timing to the preset msd for the ls2. It did not change. anything past 1/3 throttle bogs and breaks up

LLLosingit

iTrader: (4)

It could also be ignition related, As cylinder pressure increases so does spark resistance. I would make sure everything is grounded good, Double check plug gap. My Son-inlaw had a terrible miss under load and it turned out to be weak plug wires arcing to the headers under load.

nevasuma

iTrader: (1)

i'll look into that, thanks

jimmyp3353

iTrader: (3)

What is your wideband reading when it is stumbling?