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.

 

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

 

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???

 

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?

 

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.

 

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