FP Grounding
 

hey has anyone had problems with there fuel pump resistor grounding out, my car did use to run, but really rough idle, and sometimes it would die, but then about a week after, it wouldnt even start. I traced the problem to the fuel pump and something with the grounding. Has anyone else had this problem?

yeah bad grounding can cause that

well looking around my ECU today, i noticed a brown and black wire, with a plug at the end but its not plugged into anywhere..should this be plugged into something?

http://i19.photobucket.com/albums/b1...2/DSC00089.jpg

With the power fc, several wires need to be cut for it to work properly. I don't have the diagram handy, but most likely that is one of them. Just make sure the end is properly taped up so it does not come into cantact with anything. Who installed the pfc?

that connector has nothing to do with the Power FC, and it's a black wire with a yellow tracer. Anyway, that stays disconnected. You will want to check the variable resistor on the left front fender under the brake booster. verify power into the resistor and power out. the computer controls the voltage to the fuel pump from there. I have seen them go bad. Best thing to do is simply cut the two wires as close as possible to the resistor, and then sawder them together. this also makes a nice security system because then you can disconnect the conector and take it with you and the fuel pump will never run. the wires are yellow with a red tracer, and i believe the other wire is blue with a red tracer. check that and get back to me.

ok and second when i turn the car to the "on" position, the powerfc turns on, but it stays at the title screen, and doesnt go on like it should...i checked the FP relay in the front of the car, 3 of the 4 wires had power, which they shouldnt, correct?

ok so i just checked em, the blue and red has no power, the other one does, so the blue and red is the messed up one? i cut them and reconnected them and still no power...now im starting to think its the other one, and that i dont want the voltmeter to be moving

alright, fuel pump relay while on should have power on three wires; B/LG, L, L/R (L is blue).
from there, it goes to the resistor pack, and also splits to the fuel pump relay for speed. ECU can switch the relay on to give full power to the pump dependent on vehicle speed. that's shouldn't matter, but at the fuel pump with the resistor bypassed, the W/R wire should be hot, and B is ground.

make sure while you are testing these voltages, that you jump the fuel pump relay in the diagnostic connector. Otherwise, it will only run for two seconds after the ignition is turned on. you jump the relay by hooking a jumper wire in the diagnostic connector from the F/P pin to GRD.

As for your power FC, i've seen many controllers go bad where they go to boot, and then stay there. You will probably find that if you swap it with someone else's, it will display correctly. They are pieces of garbage. Anyway, check that stuff and let me know.

ok so since i got nothing for the blue/red wire, its fine since its a ground? so then what would be the problem, that wire not grounded good?

ok my car randomly started yesterday, i let it run for a bit and after a couple minutes it shut off, it did this before too, i would drive it, come to a stop and randomly shut off and wouldnt start for like an hour or so...also since i took my battery out, i jumped the battery connectors from my battery oustide the car, and there is barly any spark if any at all when i touch the jumper cables to the connecters