82transm

I recently swapped a 355 into my 88 Firebird. I put some miles on it after breaking in the cam and setting initial timing, and it ran great. After mabye 4 total hours of run time, the carb started surging, stalling the engine. The Holley mighty mite fuel pump i am using makes a loud noise when there isn't gas in it, and gets pretty hot. Also, I can see nothing but an occasional spit of gas from the clear fuel filter I have on it. After verifying that all filters are clear, lines arent bent, ect, I shot some compressed air in the carb fuel inlet, and down the float bowl/overflows and some other places. After this, the fuel pump quiets down and sends healthy pulses into the clear filter. The car ran good for about another hour after this. The carb is an edelbrock 1405.
Is this a problem with float/needle and seat LEVEL, or just the needle getting stuck?
Could I possibly have TOO much fuel pressure from the pump? It's the 4-7 psi model
EVERY component of the fuel system is new, no kinks or bent lines or anything corroded, gas is crystal clear.
Working on getting a Holley...

kirk35

Where is the pump mounted? It should be below the fuel level and as close to the tank as possible.
You should probably upgrade to a real fuel pump. The mighty mite is less than reliable and is probably your problem. I used the same pump on my engine test stand and went through three in one weekend.

82transm

I mounted the pump completely under the level of the tank, following the directions EXACTLY, like a chump. I agree that there is a lack of reliability with a $50 fuel pump, but for my purposes I really don't need reliability, just 1/4 mile passes.

Anyone else who has this problem with an electric fuel pump, I am 75% sure I found the issue. If your needle/seat is sticking in the carb it would be like putting your fingers on the end of a straw and trying to blow through it; and once the engine drinks everythinlg in the float bowl, it gets starved of fuel until the float goes all the way down and finally opens the needle/seat again.
A feed/return/regulator line setup would probably help too.

​​​​​​Rebuilt the carb, left the float hieght the same, and is now running fine.

kirk35

Glad you got it figured out. Had the carb been sitting up for a while?

82transm

Was recently running fine on another small block. I noticed that, even when dissasembled, the needle and float on the driver's side would stick when you flipped the carb around. New needles with rebuild, problem solved.