FUEL PRESSURE PROBLEM

[boydroush]

Hey whats up guys. Im new here. I have a fuel pressure problem. My fuel pressure duty cycle will not go past 50% performance. once it hits 50 the fuel pressure starts dropping at WOT(at about 4000rpm). I cant get it fully tuned because of this issue. the Duty cycle should perform up to 100% to maintain fuel pressure at about 39lbs. I have a boost a pump, 42 lb injectors, focus pump. let me know what you think.

 

[trombonedemon]

Your Fuel Injectors maybe a bit to much for what you have! Try putting your stock ones back in and see how it reacts.

 

[tonytaylor85]

Not the injectors. I would have to suspect the boost-a-pump. Take it out and see if you can get full duty cycle. I know your pump probably won't keep up with the 42#'s but you can narrow the problem down to the PCM or the BAP.

 

[Don 95Vert]

Some Ford PCMs when datalogging in LiveLink will halve the FPDC, that's what you have, so it's perfectly normal to see 50% DC on a maxed out FP. If it's getting to 50% and not moving, you are out of pump or there is another problem like wiring, etc. If you have a stock tank in a GT, you need to mod the tank or better still get '03 Cobra tank and pumps - the best solution. I have seen Focus pumps run out at 360ish and some go to over 400. Not a good situation, you need to fix it and not get on it until you get it fixed or you'll torch the motor.

Don