SaintedCorrupt

The brand new 350 in my 85 TA runs great, except when I hit about 60mph and up under moderate thorttle to WOT, when it feels like I get either vapor lock in the fuel line or the ignition cuts off momentarily until I let off to mild throtte. It is not repeatable in the driveway, so I cant tell what's going on.

I am running the same computer Q-jet , intake, and ignition that came with the old LG4 305. The rest of the motor is a mild combination of a .420 lift cam, ported 416 casting heads, flattop pistons and headers.

I've been told that the Q-jet should easily be able to handle my setup. I recently had it rebuilt at a local carb shop, and the guy told me it was in horrible shape when I gave it to him. Up until now, I've been an injection guy, so the only thing I know about carbs is how to bolt them to the intake.

So should I get a carburator manual and try and fix the problem or just dump the whole thing and spring for a Holley and an RPM? Or am I looking in the wrong place all together? Since this only happens during or after the 3-4 shift, could I be looking at a transmission problem?

Any help would be greatly appreciated.



-Corrupted

five7kid

iTrader: (14)

Most likely you've got a fuel delivery problem.

Try to get a fuel pressure gage on it so you can monitor it when these symptoms show up.

My bet is you're running out of fuel under those conditions.

mw66nova

iTrader: (13)

hmmm, new fuel pump?

SaintedCorrupt

yeah, i have a new stock replacement fuel pump. the car is at the shop for the moment getting the A/C charged. I will check the pressure as soon as i get it back. any idea what the pressure is supposed to be?

five7kid

iTrader: (14)

4 to 6 psi.

SaintedCorrupt

it turned out that the mixture solenoid was bad. i got that fixed and i know its working, cuz it makes an annoying clicking noise. also, the fuel pump makes 5 psi all the time

but at full throttle under load (uphill, or with three people in the car) the car stumbles and almost stalls until i let off the gas. the timing is dead on. is there something wrong with my carb, or the fuel just sloshing around?