i just found out that i have a fuel pressure issue. i installed 255 fuel pumps, injectors, and jdm fuel rail kit with my whipple s/c. last week at the dyno my fuel pressure was around 30psi at idle. when they rolled into the throttle the pressure would jump to 40psi and then start to bleed off back to 30psi or so. The tuner stated it could be a couple of things. His first thought was that maybe a fuel hose had come off one of the fuel pumps or the line could have a cut in it. Second he said i could have a bad fuel pump ( this will make two sets in less than 250 miles). IF these steps fail i need to check my fuel pump relays and the resistor. Starting the problem solving tonight lol.

 

For a few bucks, have you tried replacing your fuel filter? A lot of folks recommend doing that every 10-15K miles. Probably the easiest/cheapest thing you can cross off of your list, and good preventive maintenance anyway.

 

it has maybe 6k on it. i will replace it anyway just to be safe.

 

You should have just stayed with the OEM fuel rails. Try to increase your fuel pressure at idle to 39 PSI with the vacuum line removed. The JDM rail kit should have come with an adjustable FPR. See if that fixes it. If the problem still persists, you may want to look at the FPR as a source of the issue.

 

i just put the stock rails/regulator back on. JDM says they dont like the adjustable FPR now. That is why they list their rails at 280 and have the adj. FPR as a 80 dollar option. one person says one thing and another says something else. i am now going to Modulat depot for my tuning (dyno tuning) and they use the stock rails for a set up like mine. they are only around 90 miles away and if i have any more problems i can go to them in person. When i put the whipple back on i am going to check the fuel pressure to see if the stock parts fixed my problem.

 

Just a thought.

make sure the line connected to the Fuel Pressure Regulator is connected to the Lower Intake connection below the Whipple on drivers side.

The regulator needs to sense Vacuum & Boost at lower intake.
IE: After the Blower.

This lower intake connection should also be connected to the Boost Bypass
Actuator which must be open on Vacuum and your Boost Gauge.

Any problems PM or email me and I will send to a scanned diagram of my Whipple set up.

Ricki

 

thanks man but i think i have a copy of your whipple install. also all the lines are connected. that was the first thing we checked on the dyno. i ripped the gasket that goes between the whipple and the midplate so i am waiting on the new one to get here so i can do some more trouble shooting. i replaced the jdm rails with the stock ones and replaced the relay. i am going to check the fuel psi and see where i stand. i have a replacement resistor on the way also just incase (27 bucks worth of insurance lol). Then i guess it is off to pulling the fuel pumps again to check them and the lines. i can not say enough about the help i have had from this website. thank you all.

brian

 

As your running 225's i would junk that duel voltage system.

I run mine direct via heavy duty 70amp relay wired into the fuel control system.
(After the Shut Off circuit)
Fused with a 20 HD fuse that is continous rated.
Heavy duty cable and earth line too.

Pumps run full power all the time.