Chakadog

I was wondering if anyone could help. I replaced the original mechanical pump because it was leaking from the weep hole after driving and car was shut off I would find a large gasoline stain in my driveway. I also want to mention that the car ran good before the pump change I replaced the pump with a new original AC Delco 41216 rated at 9 psi max from Rock Auto. After i replaced the pump the carburetor was flooding with gas coming out of the top of the Carb. I figured maybe the float and needle were bad or had dirt in the needle seat. I bought a new float, needle and seat and replaced the old ones. The carb still flooded. I then replaced the carb with another one and the same thing. I was wondering about the fuel pressure overpowering the needle valve and keeping it from closing. I took a pressure test with a gauge and the pressure was 8.5 psi is that too high and causing the problem. My Trans Am also came stock with an electric pump in the tank and the rubber fuel line that goes to the mechanical pump pulsates quite a bit enough to make movement of the hose. Do I need a pressure regulator now to lower the pressure to between 4-6 psi? Any suggestions would be appreciated

John in RI

iTrader: (167)

If your using an Edelbrock or Carter,...... you'll need to install a fuel pressure regulator. 5-6 pounds MAX; about 5.5 is where I like to set them.

This is what 2 different Edelbrocks did to 2 different cars when using a 'stock replacement' fuel pump: Picture taken AFTER the car was shut off,.... The Carbs were just filling up with fuel until the fuel pressure dropped enough for it to stop.



Installing a FPR & setting it to 5.5lb was all it took to solve the problem.

Chakadog

Thank You for your response, I am using a stock Rochester E4ME but it sounds like the same problem that you had, I will look into getting a fuel pressure regulator
thanks again

//<86TA>\\

iTrader: (14)

Why is there an intake pump if the car was a carb car in stock form? What's the 8th digit of the vin?
8.5psi is too much for a carburetor. It needs a regulator.

Chakadog

The 8th digit is an H
I am the original owner bought it new in 87 I had to replace the rusted leaking fuel tank about 10 years ago and to my surprise it had an electric pump in it I replaced it with a new original one along with the new tank. This was my first replacement of the mechanical pump last week the old one lasted 32 years and had no problems until I put in the new AC Delco replacement. I was not expecting this flooding problem

Manic Z

iTrader: (1)

Some LG4's and L69's had an in take 'helper' pump.
I think it was to try and eliminate vapour lock.