I have an 76 Stingray. I have put 2 new fuel pumps on this stock 350. When I put the pedal down it runs out of fuel. When I clamp off the return line to the tank the car runs/responds fine. Any thoughts? I can't imagine that I bought 2 bad fuel pumps.

 

im still trying to find out whats up w/ that on mine too but im not to worried about it now, i put a newer 350 in it and it dosnt have the return fitting so i just capped the return and im running fine. does it run good at idle?

 

imjustsean, thanks for the reply. Yes, it idles wonderfully. I'm considering capping the return and putting a two valve fuel pump as well. However, I'm going to keep the original 350 in it at this time.

 

i think whats happening is the return line is either pushing air up thrugh the system and leaning it out or somthing to that affect

 

Make sure the gas cap is sealing tight. It's supposed to be a closed system.

 

Thanks for the gas cap advice. However, I sealed the gas cap with plastic to make sure that it would not leak and the car still starves for gas.

 

You could have a leak in the top of the tank or in the fuel filler line itself. Just another thing to think about.

bill.

 

You have already found out the carb is starving for fuel but the question is why?There are several possibilities.One is the tank vent might not be working via the charcoal canister.To check for this leave the gas cap loose and drive the car.If this fixes it it is because the vent wasnt allowing air to go into the tank as fuel went out.Another thought is the sock in the tank on the fuel line restricting the flow going towards the pump.My next thought would be directed towards the fuel pump that has a return.This fuel pump is pretty simple.It has 1 inlet and 2 outlets.On the outlets the fuel is compressed into a common chamber with 2 outlets-one outlet or hole going to the carb is about .270 diameter and the other is very very tiny around .070 diameter going back to the tank(the return)-so the fuel will take the easiest path and go towards the carb until something restricts it-like the needle and seat in the float bowl when its full or the fuel filter if it is dirty and then it sends it back to the tank.If the filter is getting dirty blocking the return might be enough to push through the filter and allow the engine to run.My last thought is maybe the fuel pump is short stroking-in other words the pushrod for the pump is not giving a full stroke or push to the fuel pump lever.The most common cause for this is the push rod (being driven by the cam lobe) is bent.Usually if it is bent you hear a tapping sound coming from it that sounds like a loose rocker arm.The way it gets bent is when changing the fuel pump you screw in a bolt to hold the rod up in place and it is screwed in too tight thus bending the rod and it can no longer move properly.Another reason it could be short stroking is a very long shot and that is the lobe or escentric on the cam is worn.

 

Any chance your "S" hoses at the fuel pump are collapsing? Always a good idea to replace them if they're old.

 

Hey Roger you are full of good tech. advice . Stick around.We may need you later.Oh yeh,welcome to the forum.Also welcome to Stoge and Sports12.You all have fun now , sleep time got to work tomorrow.Talk at ya later. Oh ya, hi Bill hi Dave!! By Bill by Dave!!!