I dont understand why I keep hitting 80% duty cycle on my 550/1680 cc injector setup. I mean, the car is not more than about 350 rwhp. on a t04b at 15psi of boost with all the supporing mods (Haltech, fmic, long list)

How long do Walbro 255 lp/hp pumps live for?

I've recently redone the fuel system: IE new injector orings, grommets, and ran parallel system from the stock filter to the fuel rails and finally to both inputs on the aeromotive fpr.

When my engine is running the pump is seeing 12.5v; thats down from about 13.9 at the battery. Seems theres some 14ga wire going back there.


Things Im going to try this weekend:

1. Verify that my FPR is set to 43 psi static pressure (35-58 psi operating range)
2. Monitor my fuel pressure via guage from inside the car at WOT
3. Verify the fuel filter I replaced last year is still OK
4. Think strongly about upgrading fuel pump wiring
5. Think about replacing the fuel pump
6. Think about professional injector service
7. Think about servicing the Auromotive FPR

 

Twelve gauge wire with a relay for the pump would help. Walbros are known to fail brand new not to mention if it's one of the e-bay made in china replicas that's been floating around a lot lately.

 

No I dont think its an ebay pump, but it has about at least 25,000 miles and then some and may have been bought used some time ago. It is an unknown cause this car was already modified when I got it.

Ive got some left over 10ga wire from an old old stereo instalation which should be enough to run back there, and that should support any current and future fuel pump mods I'll need or require.

How can I get a really nice large tight fuel proof terminal to inside the fuel tank?

 

Having a run of 10 gauge from the battery, with 8-12 inches of good condition 16 gauge wire going into the fuel tank, isn't going to cause problems. Take a look at a 30 amp fuse as an example; there's not a lot of conductor material there, and it will support its rated current without burning out. The real problem is high current across a long run of high gauge wire, because of the voltage drop it causes due to resistance.

 

OK I found two problems:

1. My fuel pressure guage mounted to the FPR was readnig 8psi too high, so when I had it set at 42, it was doing 36.

2. Some idiot put 440cc injectors in place of my stock 550cc

 

Also at 15 psi you can make over 420 h/p have you dynoed the car? If not you are just guessing and need to check for a reference!

 

rewire that fuel pump and switch to a Denso pump (Cosmo or Supra TT) if you want something that's made better