Engine Bucking

[Mopar-muscle]

boost , what lift pump do you have and where is it located ? i don't think that the TPS controlls the pump that quickly . sounds to me like a fuel problem , i suspect the lift pump , and its location , though i have mine still in the stock location .



when you changed banjo bolts did you modify the banjo fittings between the lift pump and the fuel filter ? those are very restrictive , i just replaced that line completely with 12mmx 1. 5 to AN6 fittings and a length of hose with the appropriate connectors ...

 

[Boost]

Mopar muscle,



The lift pump is a stock pump in the stock location, replaced about a month ago by the dealer trying to figure this problem out. I replaced the banjo bolt at the VP44 with Genos bolt but no other mods to the fuel system. I might try a second pump at the tank and leave the stock one also. Cuminntstrkn did this and is running way more fuel than I am with good pressure. The thing that I dont get though is it has good fuel pressure at idle(16lbs),and at WOT(7+) but goes to zero at 1/2 to 3/4 throttle and starts bucking.

 

[PROSTAR190]

Boost,



I have the same exact problem and I have added a pump on the frame rail by the fuel tank. It did not help. I am wondering what tells the pump/pumps to operate, if there is something controlling the signal from the pressure switch (is there a pressure switch and when is its control activated?) to the lift pumps that is not functioning correctly in the midrange throttle positions. This problem is about to drive me crazy. I have not verified that I am loosing pressure at mid throttle position. I have thought about wiring a manual switch to the pump and see if that eliminates the problem at midrange.