no fuel pressure? 99 GT

[trueblue01stang]

to make a long story short my car died out on me twice on xmas eve. pulled the code and it said it was the fuel pump. it was fine for the next couple of weeks but just for good measure i replaced the pump with an SVT focus pump on sunday. ever since then the car hasnt been the same. after the pump i took it out for a drive and it would go up to 3500 so i figured it was just the ECU resetting itself and took it easy on it for a while. i got on it again after a good half hour and again it didnt go past 3500. i came home and pulled the codes and it came up at P0190 and P0193. i started looking at the data thru the predator and the FP is only at 10psi at idle, and anywhere from 3-5psi before start up, if i give it any gas it drops down. so far ive replaced the FRPS, battery, fuel filter and PCV valve. if i bleed the schrader valve FP will go up to 17psi and then drop back to 10 within a few seconds. ive noticed that as the pressure is dropping so is the FRPV which id assume is the FRP volts. could this be the alternator? any help is greatly appreciated.

kyle

Edit: car is pretty stock. BBK CAI, SLP LM 2, Mac o/r X and a predator. it has exactly 73600 miles on it.

 

[ZeroOneStangGT]

subscribing..

 

[sgarlic]

Could be alternator troubles or weak battery (in conjunction with crappy alternator) .. so much of the cars now a days depend on electronics to run properly, a bad battery or alternator can cause so many problems it's not even funny.

 

[trueblue01stang]

i talked to my buddys dad thats a mechanic and he borrowed me a voltmeter to test the battery with. it was at 12.4 and then 14.2 with the engine running. i checked the FRPS and it showed it was putting out 4.6v, which seems about right since it should be anywhere from 4v-6v, but its only showing up around 1.11v thru the predator. i guess he also has a program on his computer that you tell i what codes are being thrown and itll give you a step by step on what to check.

 

[trueblue01stang]

i talked to my buddys dad thats a mechanic and he borrowed me a voltmeter to test the battery with. it was at 12.4 and then 14.2 with the engine running. i checked the FRPS and it showed it was putting out 4.6v, which seems about right since it should be anywhere from 4v-6v, but its only showing up around 1.11v thru the predator. i guess he also has a program on his computer that you tell i what codes are being thrown and itll give you a step by step on what to check.

 

[trueblue01stang]

i talked to my buddys dad thats a mechanic and he borrowed me a voltmeter to test the battery with. it was at 12.4 and then 14.2 with the engine running. i checked the FRPS and it showed it was putting out 4.6v, which seems about right since it should be anywhere from 4v-6v, but its only showing up around 1.11v thru the predator. i guess he also has a program on his computer that you tell i what codes are being thrown and itll give you a step by step on what to check.

 

[Isaac-1]

I hate to say the obvious, but it could be a defective fuel pump. The symptoms are almost identical to when my fuel pump went out, the only difference was mine did not act up unless the car was driven for at least 100 miles.

Ike