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

 

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.

 

hmmm, new fuel pump?

 

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?

 

4 to 6 psi.

 

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?