nrmskate

Hey guys, I just did a 4.3 to 5.3 swap in my 03 silverado. I swapped in a 02' engine with return style fuel lines (03 v6 silverados are return style) and I also converted everything to AN fittings and Nylon braided line. I accidentally hooked up the fuel feed to the return (I know, my mistake) and cranked it a few times. The truck did start and run before when I had the stock hardlines hooked up. I found out that my feed was on the return and corrected them, but now the truck will fire once and just shut off. I think I may have messed up my FPR by trying to run 60psi of fuel the wrong way, but I wanted everyone else insight on this as well. The fuel lines are for sure hooked up right, the purge line I kept the same and didn't convert to AN fittings, I only did the feed and return lines. I am just running 6 AN line from the feed all the way to the fuel filter, and I just did compression fittings on the return line, so most of it is still the stock hardline.


Things I have checked:

VATS (Definitely not it)
Pressure at the rails

Atomic

iTrader: (42)

Turn the pump on without starting the engine and see if the regulator holds pressure. If it does, then its fine and you have a tune problem.

nrmskate

Just see if it holds the ~50psi at the rail?

Atomic

iTrader: (42)

Yep, if it holds pressure its doing its job. This a stock regulator or aftermarket one?

nrmskate

It's the stock regulator, I would like to upgrade to an Aeromotive FPR, but I haven't done the research to see how that would work on a stock 5.3 truck intake.

Thanks for the help Atomic, I will check to see if it holds pressure when I get home.

nrmskate

Okay, so the new FPR is installed and it's still giving me low fuel pressure at the rail.

I have about 5psi when pump is priming and about 11psi when it's cranking. I've tried 3 NEW fuel pumps, ran all nylon braided fuel line, 3 fuel filters, and now a FPR. What could my problem possibly be?

Atomic

iTrader: (42)

Whats the pump voltage?

nrmskate

It was 12.8v before I dropped the bed back down, I will check it again tonight. I have all the bed bolts out for now so I can check it pretty easily.

06murder

Have you change the fuel filter?

nrmskate

3 times yes