carguy327

I am currently working on converting my 1988 5.0 Mustang from fuel injection to a Holley 600 Carb. I bought this from a person who began this project, but never finished. He wanted to sell it cheap so I decided to jump on the opportunity, not really knowing what I was getting myself into. Right now the set-up is as follows...stock fuel pump, an aftermarket Holley FPRpushing 6-7psi into the carb. It idles perfectly, but when attempting to drive it, it will run fine for about a mile and then it will stall out from fuel starvation. I am basically looking for information from someone who attempted this and knows how to fix these problems. I am not sure if having this set-up even works, or if I need to change the fuel pump, bump up the pressure, or where the problem even lies. I would really appreciate any advice that you couldgive me. Thanks for the help.

mjr46

When you say stock pump do you mean they are still using the intake Fuel injection pump and have reduced pressure via a regulator???? the excess should of been looped back into the return line via an extra port on the regulator...when correctly done to do it that way...........How do you know it dies due to no fuel????.. can you hear the pump running when it dies???

carguy327

Sorry,yes...there is a return line going back to the tank from the regulator. So that is hooked up properly. When it stalls out, I can hear the fuel pump working, till the pressure builds up. And then I am able to turn it over again. But it will run for about another mile before the process repeats itself.

mjr46

dOES THE FUEL PUMP DIE OUT CAUSING IT TO STOP PUMPING FUEL?? Do you hear the fuel pump die out before the car stalls out...cause on a carbed car you'll have a delay as there will still be adequate fuel in the bowls to run for 10 to 20 sec more before complete stall out

mjr46

if you have replaced a fuel filter rule that out if not check it for a restriction and if that's not the case on the end of the fuel pump there is a sock/ small bad filter...and if it's partially restricted/ sucking up crap at the bottom of the tank then it'll do what you describe and when it sucks up enough crap at the bottom of the tank the car can't draw enough fuel and it dies out due to starvation but as it sits still shut off the debris falls back off the pick up filter and wha la...enough area is now free to draw fuel and the process starts over like a circle each mile you drive....just a thought..seen that happen many times on various model cars

carguy327

The fuel pump is definately still running. In fact it runs constantly. Even if I just have the key in the on position, without the motor actually running, it continuously runs. It never seems to prime and stop like a normal fuel injected car with an electric pump would do. I just figured it was due to the carb set-up. But if this is a symptom of a problem, I guess it would be a good place to start with the diagnosis. But then is that the regulator going bad or the pump not pushing enough fuel?

mjr46

well the best way to determine if you have a fuel sytem delivery problem is T in with a pressure/vaccum gauge as you'll need one that can read pressure between 2-8 psi at least...my vaccum gauge does vaccum and pressure but anyway.......you'll need to T in as close to the carb inlet line as possible and tape the gauge to your cars windshield and go for a ride and watch pressure as the car starts to stall...if the vehicle maintains at least 4-6 psi..or it stays constant then after it stalls hop out and look down the throat of the carb and snap the throttle a few times and see if the accelerator pumps are squirting fuel into the bowls..if they are then you may be able to rule out a delivery problem and might want to check the setting of the float levels on the carb

carguy327

Oh, that's a good idea. It did sit for a while before I bought it. I immediately replaced all the filters and ran a full tank of fresh fuel through it...and it was definately brown in color at first before it finally became clear. I will start with replacing the tank, eliminating the deposits and see if that makes a difference. If not, I will repost. I appreciate the help. [sm=smiley20.gif]

mjr46

no problem!! if your gonna drop the tank...replace the sock/filter screen on the end of the pump at the very least...they only cost a few bucks!!!! good luck!!!!