86 Camaro Fuel starvation

MADDAWG

MEMBER
1986 CHEVROLET CAMARO

Hi guys;

I have a fuel starvation problem, but it's not related to cornering. I know already that the pump is having problems bringing fuel to the carb. If I go through the gears hard (bringing them up to the RPMs), it eventually falls on it's face. Runs out of gas. Pump can't keep up. This is confirmed by the clear fuel filter being empty after stopping the car. When it's running, you see the odd little gas spew into the filter. I would say every 2-3 pump strokes, I get a shot of gas. This started after my 1st tank of gas this season. Before I parked the car in the garage for the winter, I added fuel stabilizer. When I took the car out, I filled it up with Sunoco 94 and added a can of "Fuel System Cleaner". By the way, it does it whether the tank is full or near empty. No change.

Things I have done so far;

-replaced fuel pump with a high volume (120 GPH). This helped a little.
-checked the fuel line from front to back.
-new gas cap

For anyone that's taken out the unit out of the fuel tank of a carbed 3rd gen F-Body car, what exactly is in there? Is there any rubber lines or are they all steel?

I'm trying to keep from dropping the gas tank because it's a PITA to do and I don't believe I'll find anything in there. Things I'm pretty sure it's not; vapor lock. If that was the case it would have done it last year also since I didn't change anything in the fuel system since I got the car.

Things I will be doing in the next couple days;

-backflow the fuel pump/lines (reverse the lines on the pump to clear any potential debris in the line to the tank)
-replace all the sections of rubber fuel hose with new pieces.

Does anyone else have any suggestions?

This is on an 86 Camaro Z28 with a 350 CID with 310 RWHP, modified QJet carb, and mechanical fuel pump.

Thanks

1 Reply

E40WATER12

MECHANIC
522 POSTS

You know, What you have just explained, My buddy is having the same problem with his 87 camaro, he got 350 sb with, We pulled the motor put it into another truck, He bought high volume fuel pump mechanical, Still doesnt the same thing, We hooked up high volume electric fuel pump same problem, Only when the normal temp is set, then fuel bogs, motor, stalls, We pop the fuel feed line to the carb fuel pressure pushes the fuel out of the line, Its like carb is blocking the fuel entry, We pulled the gas tank, on the camaro, That wasnt a good task, Complete waste of time, It ran good with a line feed to the gas can, My buddy is getting his carb edelbrock rebuilt, Hopefully that corrects it, If not something is messed, We did a compression test on the motor, No vaccum leaks on intake or motor, piston compression is 175 psi each cyl, Could be a flaw GM has done.