deth_1970

I have a 91 camaro, 305, carb modded, from tbi, now everyone once in ahile it would act like it was starving for fuel, and start surging, swinging the rpm's range by about 1500 rpm's,
well today it started acting up, before it would do it, and usually clear up shortly, well today it started, it, and left me stranded,
while doing this, it would start die, or start and idle rough, and at a low prm, and if i pressed on the gas, it would accelerate, the die, WOT would just kill it
now i was looking at the metal line that the previous owner reused from the tbi unit, it was resting in the intake manifold, and on the valve cover right behind the alt,
It did finally get me home on its own, and acted like nothing was wrong, and ran great again,
I am looking into a new feul pump, and re routing the fuel lines fromt the pump to the carb, and replacing the inline fuel filter, and adding another before the carb,
does this sound about right, have I missed something

five7kid

iTrader: (14)

What do you have for a fuel pump now?

deth_1970

some pos from napa

five7kid

iTrader: (14)

Mechanical? In-tank electric? In-line electric?

deth_1970

sorry, its an inline electric, sitting in the engine compartment, its been a long day, I was stuck out in the heat

five7kid

iTrader: (14)

Okay, we're getting a little farther. Was the original in-tank electric pump removed, or is it sitting there inoperative in the tank requiring the in-line electric to pull fuel through it? Do you have a regulator in the system? If so, is it a dead-head type or does it use a return?

deth_1970

all the work so far was done by the previous owner, so some answers I cannot give at the moment
the fuel pump in that tank, I do not know the statues of, the pick up tube in the tank I do not know the status of,
No regulator, the return line was capped off, the fuel pump is just a standard napa cheapy square type, one line in, one line out,
I had planned on changing the fuel pump, Im looking at the edelbrock one made by essex, pre set pressure of 6.5, adding a plastic riser plate, and swithcing over to a performer intake which I had for one of my trucks, and changing out the fuel filter, and adding one before the carb,
I was hoping they changed the in tank pickup tube to a early model 3rd gen carbed type, but I am unsure if they did,

five7kid

iTrader: (14)

Sounds like it is all stacking up to give you problems. You really need to confirm whether the in-tank pump was removed, and about the only way to do that is to drop the tank.

A return is a very good idea, because it keeps fuel moving through the line so it doesn't pick up as much heat, and keeps cooler fuel from the tank in the system. So, even if you go with that self-regulated pump, a return style regulator is still a good idea.

Having the pump back by the tank is also a good idea. Vapor lock occurs when hot fuel being sucked by the pump turns to vapor - low pressure and high temp = liquid -> vapor transition. The pump can't pump vapor, and the carb can't use vapor even if the pump could get it to the carb. When the pump is back by the tank, the fuel temp at the pump inlet will be lower, so it will suck on liquid not vapor, and when the fuel is up where it gets hot it will be pushed under pressure - which means it can't vapor lock.

Of course, if the fuel is boiling in the carb bowl, that's a whole different problem.