Bagg'd99

After I got the whipple on It would always put out 59lbs of fuel pressure at full throttle. After two days now when I go full throttle it will put out 59 right away and then instantly drop down to 40-45lbs. NOT GOOD. If I ease into it, it is fine untill higher rpms in the next gear, but if I just mash the throttle it will drop. Is my fuel pump just getting weak? It has a newer fuel filter on it (5,000 miles ish). I called Whipple about it, but since I had ditched their computer and had one custom burnt they said sorry we can't help you. So I need to find out what to do quick. The truck has the following
5.3 with Whipplecharger, Westers Whipple tune, 42lb injectors, Doug Thorley Tri-Y's, K&N Open air, Hypertech T-stat, Flowmaster mufflers, Corvette Servo and all the free mods.

Black Blown 02

Do you have an inline fuel pump? I don't know if the whipple comes with one.

greentahoe

iTrader: (2)

Maybe there is a problem with the tune. It takes a period of time for the PCM to reset after a new tune right??? Is it possible that Westers didnt add enough fuel in the upper RPM's at WOT???

BenKey

iTrader: (1)

The tune should only deal with how much the injector is releasing. If you're having a pressure drop, I don't know of anything it could be in the tune.

How much boost are you running? Have you changed out your stock pump, or are you running an inline?

ktmrider

I THINK most SC kits come with an additional inline fuel pump and/or FMU. One other option is to install a relay device or voltage booster in the fuel pump circuit. I have heard that any type of voltage drop can affect flow. Some folks with underdrive pulleys on the alternator have experienced this issue.
I agree with the others, I doubt it has anything to do with tuning.

Bagg'd99

I just ordered a new Delco fuel pump for it and I will also run an additional inline pump to help it. Watching Ebay.