Ok mass confusion has struck me i went from a fuel injected 2.8 to a 355 with a holley 650 carb, now after i drive it for 10 minutes or so it dies....it acts like its not getting fuel which may be due to i have 2 fuel pumps the one on the engine i put in and the other electrical pump in the tank....could this be the problem? i have heard that there is some sort of shut off valve on the electric fuel pump that may cause conflict when the mechanical pump is attached, i've heard it could be a bad mechanical pump, all though i have been through it all i've had my timing changed cause it was said to be too advanced, i put in a new ignition module, ignition coil (h.e.i.), i put on a new in line fuel filter, i've tried pulling the fp/inj fuse to kill the fuel pump and it is still having fuel problems and every time it dies it gets a little bit more frustrating, help me if you have any ideas from what the hell this problem is when it dies it just acts like it has no fuel, so it dies and i pump teh gas pedal a few more times and it starts and then gets no fuel its not electric i'm almost posotive of it help will be greatly appriciated

 

how much fuel pressure do you have at the carburator?

 

5.5 psi i got a fuel regulator

 

How much fuel pressure does it have when it dies?

Do you have a regulator that utilizes a return line?

 

not quite sure i follow return line? but i was thinkin i know that pump has a shut off valve i cut the power to it and it wouldnt send any fuel at all would hotwiring the fuel pump work where it has that computer that would read a sensor to send the fuel to the engine?

 

without a return line you run the risk of getting vapor lock which could be your problem.

 

its not vapor locking the fuel lines arent anywhere close to a hot surface i am about posotive its that computer and that pump would anyone know about the electronic fuel pump on that shutting off the fuel to the car after it goes to the computer?

 

why would i need that return line? and where would it go please explain i am confused?

 

The electric pump in the tank needs a constant flow of fuel to keep it from overheating. If it doesn't have that, it will get weak as it gets hot. The mechanical can't pull through the electric to make up the difference.

Get a regulator in there that has a port for return, and hook it to the original V6 return line.

 

five7kid your a stud lol you know everything and anything and i appriciate the help but i have another question for you or anyone else knowing the answer, so i just take the mechanical pump completely off and run the consistant electric of are you suggesting removing the electric pump all together, how'd you do it on your camaro when you swapped from your 6 to an 8???

 

I didn't have an in-tank electric. My '82 V6 was carb with a mechanical pump.

You don't need to remove the mechanical, you just need to get a return between the mechanical and the carb.

Although I haven't tried this, I don't know why it wouldn't work to put a stock style V8 mechanical on. It has the return built in, will regulate the pressure (basically a relief valve), so the electric could push through it all day and everyone will be happy.

 

Run a mechanical pump or keep the in-tank electric pump. You dont need both. If you keep the electric pump, you need to splice the tan wire from under the hood to a wire that is hot only when the ignition is on. You also need an adjustable fuel pressure reg with return line (MAA-4309, $74.88 from Summit) There are 2 fuel lines that come out from under the car. The larger one is the incomming fuel and the smaller one is the return line. The reason it only runs for a while now is because when you turn the ignition on the electric fuel pump pumps for like 2 seconds then shuts off, enough for the engine to run for just a short while.

 

where's the tan wire located?

 

When I did my V6-V8 swap it looked like I took a machette to the wiring harness, lol. I got mine out of one of the thicker bundles around the drivers side area. Its small, tan, and has a white stripe I think. Some people may say you have to get it from under the carpet near the trunk, but thereye wrong. Start looking, find a hot, splice it in.