boostem2

hey i have a 02 em2 that ive boosted and been enjoying. I recently put it on the road last week and its been running rough. I knew why and decided to take care of my vacuum leaks and fuel pump replacement. I installed a missing link which made an incredible difference with boost. Then i decided to take on my fuel pump, which has "fueled" the problem im in now. Prior to replaceing the pump i had no starting problems at all. I removed the fuel pump fuse, to bleed fuel pressure, then i removed the line from my tank. Installed my 255 lph walbro (uss342). replaced the fuse i removed for the pump and cranked. The car innitially puttered like it wanted to start, but didnt. Long story short, i reinstalled the stock pump and it started right up. I took the car down the street and it stalled on me. I tried to start it again but it wouldnt. Ive checked the fuel pump fuse, and the main fuse, and they are both good. My fuse pump relay isnt being powered because i dont hear it click at all and the 15a fuse for the pump is good. Ive checked everything i can think of but nothing works. Oh, and when the pump runs, it only runs in postion 1 and 2. When i go to crank, the pump completely shuts off. Ive checked and verified this at the fuel rail. I need some help with this and i dont wanna take it to a dealer. Can someone help me i would greatly appreciate it.

lazlong

Check to see if the relay is bad. While you're in there, look for bad connections/burnt wires.

boostem2

ive checked the connections, and nothing is damaged. I also checked the relay. I think it might not be getting power, or grounded right. Does anyone kno the voltages, or which wire is for what so i can troubleshoot it. Possibly have a diagram or schematic My fuel pump turns off when i go to crank, and if it didnt it would start.

rodrj145

hey i have an 03 coupe, i had the same problem and it turn out to be the TPS, strange but it works perfect since..

boostem2

Realy?? the TPS? ok. im going to check it right now.

boostem2

yep. nothing for the tps. Does the fuels pump relay control the injectors as well?

boostem2

does anyone have any other ideas I can try? do you think it could be ecu controlled?

rodrj145

not a mechanic just from experience, good luck

boostem2

ok so im onw step closer, and i came across a new problem. I started checking my grounds at the pump and power at the relays and i discovered my sending unit wasnt properly as guage works now! grounded. i grounded it and my gas guage works now! still doesnt start thou. I grounded a pin on my FI relay and now the fuel pump sends while i crank. My engine putters now when i crank but it still doesnt start. I also checked my injectors because i have fuel to the rail and pressure now, its just not reaching the injectors. I have 12 volts positive at all injectors but NO GROUND! I know the ground is controlled by the ecu, but i dont believe the ecu it bad. Am i missing anything guys?

lazlong

Back-probe ECM/PCM connector A2 (yellow/black)and A3 (yellow/black). Should have battery voltage with the ignition ON(II) and 0 volts with ignition OFF. Connector A is the bottom connector when looking at the ECM/PCM while it's in the dash.

boostem2

thanks lazlong for the info. im going to check that in a few minutes and let you kno the results.

boostem2

still having this problem. put my car down for a few to play with my CBR now i have to get my coupe back running. I was wondering if anyone had a diagram for the main and fuel pump relay as well as fuel pump diagram because i need to get to the bottom of this. So far my status is key on position 2 i have few lights on dash. Battery light and srs. i feel as thou there is an open and my green key light, as well as check engine light are out. When i ground the red/yellow wire the lights do turn on. ive been looking for diagrams online for these relays so i can verify that they are operating right any help would be appreciated!!!!

boostem2

anybody?