fuel pump not turning on

[DisFrikkenWill]

well yesterday i installed a walbro fuel pump in my ka24de-t and started up my car and it ran better then when it had the stock fuel pump. we shut the car off thinking everything is fine. we install a electronic fuel pressure gauge, tapped in the middle where the fuel filter and fuel lines that goes to the fuel rail. then started up the car and it ran fine....we revved it a little and the car sputtered and died out. we tried starting it again a couple times but it wouldnt start. we checked all the relays,fuses, uninstalled the fuel pump like 5 times, we even put back the stock one to see if it would work but still it doesnt. we even tested both fuel pumps stock and the walbro on a battery and they both work fine. what do you think happened? what could it be....the car ran fine for 2 days after my t25 install untill the gauge part. wich is wierd. everything seems fine. when i turn the key to the on position the fuel pump doesnt turn on. we even installed a NEW fuel pump relay and still it doesnt work. when we touch the ecu wire # for the fuel pump relay with a test light and ground it to the car the fuel pump turns on like it should when the key is in the on position and when we turn the key in the off position it goes off like how it should. like the ECU or something isnt getting enough ground? cause how the fuel pump works it goes like this?.....from ecu--->relay---->fuel pump? i was looking at this also but it says for s14 only and i have an s13. http://www.ka-t.org/walbrorewire.php i dunno though would that even help? i really need help please, thanks!

[elwesso]

sounds like the contorl module isnt getting a good ground... Take off the ground wire and run it directly to teh chassis ground.

[DisFrikkenWill]

take out the ground wire? wich ground wire? like wich pin? sorry i dont get it. the ecu right? its wierd cause when i touch the pin for the fuel pump relay with the test light and the other end to a ground the fuel pump turns on, i would touch the other pins the same way and it wouldnt do anything.theres a couple times i could switch through ecu's (i have 2 ecu's, one is broken) i can connect the ecu harness plug to the tuned ecu turn on the key to on and then off and then connect it back to the stock one it sometimes works, like i could just swap ecu's then swap back to the stock one turn the key and the fuel pump turns on like normal, start the car it would go and then sputter and then die. i really need help on this cause this car is my daily driver. could it be cause i didnt take off the negative side of the battery when i changed my fuel pump?

thanks for your help, your the only one responding to my thread
Modified by DisFrikkenWill at 11:30 PM 11/19/2006

[Acecool]

Make sure the fuse didnt blow.

[DisFrikkenWill]

yeh it didnt blow

[elwesso]

ive heard of this happening, somewhat randomly on the Q45s... The ground becomes weak.... youll take the ground from the fuel pump and ground it directly to the chassis for a good clena ground...

I reckon youll need a wiring diagram to get anywhere, ill see what I can muster.. If I forget dont be afraid to remind me! we'll get this taken care of, sounds pretty simple to me.

[DisFrikkenWill]

ok ill try that, btw this is a 1991 240sx if that matters...thanks!

[sliders]

if you can swap ecus then swap them back and it works for a little bit then you have a bada wire in your connector and with you moving it around it brings it back but then dies check your ecu connector wires

[DisFrikkenWill]

THANKS FOR EVERYONES HELP! it was one of the ground wires for the ecu. grounded to chasis. used the FSM too. thanks again NICO YOU ROCK!