masa_3100

iTrader: (1)

So guys, Im stumped on this one. Ive had fuel electrical problems before and I know my way around it pretty decently. Considering I also took a No Start diagnosis class. But this has finally forced me to put up a thread for help. I jumpered the Fuel pump test plug near the AFM and the car didnt even start up or try to catch on. I also listened for the pump(have a 255 walbro so its VERY EASY to hear) but didnt hear it come on with it jumpered at all, even tried feeling for vibrations at the pump but silent as death. I then checked the voltage going through the jumper point and had none. But I have 2 volts at the circuit opening relay on the black/white wire which is supposed to have 12volts so its really weirding me out.

Since I am stranded I cant go to the library to borrow the hayns manual and look at the wiring diagrams. And for some reason I cant find the diagram that shows me where the black/white wire comes from. All I can find and have are the fuel related diagrams with it coming from nowhere saying 12v. So any wiring diagrams showing me where that sucker is connected to would be great.

P.S. Ive done the two diagnostic tests where you unplug the AFM and see if it just starts, and the test where you jumper the plug near the AFM to turn on the pump directly. With neither working at all.

masa_3100

iTrader: (1)

This car is my one and only daily driver. It was running perfectly fine other then the small oil leak which I always made sure to top off and maintain oil levels. So this is really baffling. Does anyone have a link to a wiring diagram showing more then just the fuel section? Maybe a more broader diagram with wires leading to the fuel pump? Also does anyone know if there were fusible links in the FC? I know there are some in the SA22 and FB. Im pretty sure it doesnt but I just want to check with any gurus that might be lurkin. Any input is greatly appreciated!

SirCygnus

iTrader: (1)

did you check the pump itself to see if it died?

Lagrange 3

^ what he said, pull your carpet, there's 4 fuel pump door screws, then like ten smaller Phillips screws and 2 fuel lines you have to remove.

then pull the assembly out, get 2 jumper wires(1 foot scrap wires ) strip both ends and jump +- to the pump. if it turns on, jump to the fuel pump resistor relay ( near passenger headlight) and check for a ign + signal, if thats all good, check voltage drop between relay and pump power and ground.

masa_3100

iTrader: (1)

Its a new Walbro 255 pump that I had put in less then 4 months ago. Properly by soldering the wires then shrink wrapping. I also dont hear the fuel pump relay(circuit control relay) clicking on or off like I normally could in the past. Thanks for the input though, I wish it was that cuz that would have been easier to diagnose/fix considering Ive done it before.

That passenger side headlight fuel pump resistor relay. What does it look like? Ive never checked that thing. Might be the cause if its before the circuit control relay. Only have about 2 volts coming into the control relay through the black/white wire.

satch

iTrader: (1)

Did you check the 15 amp Engine fuse (powers the B/W wire). The B/W wire you checked. Was it located in the top row center position of the relay and did you do this test w/key to on? Also, the check connector jumpering of the fuel system passes a ground signal and not a voltage signal.

masa_3100

iTrader: (1)

Yes I tested the B/W wire with key to all positions mainly to On because i know its supposed to only get power while its at On.

I checked all engine fuses and they looked good but ill double check. None of the cabin fuses have to do with the fuel system right?

flaco

iTrader: (7)

put a relay .. a 12v relay open with the switch if you want and thats it..

from my experience i had a couple of walbro pumps fail running them with the factory fc system. after i did the relay problem solved

satch

iTrader: (1)

The Engine fuse is a cabin fuse.

masa_3100

iTrader: (1)

That is hilarious I cant believe I missed that! I replaced the 15amp fuse and she fired right back up. But is it only me who finds it weird to have a fuel pump fuse located on the cabin fuse block?

masa_3100

iTrader: (1)

So the car drives fine now but the fuse blew again, so I am now actively looking for the short that would be causing this. Do you guys know of any common shorts that may occur?

satch

iTrader: (1)

The Engine fuse powers the Main Relay, alternator and Circuit Opening Relay (and the Lock Up Relay found on automatics). The fuse powers the B/W wire in the two wire plug at the Main Relay, and the B/W wire in the two wire plug connected to the back of the alternator. Unplug one of the three items powered by the fuse and see if it continues to blow w/key to on.

masa_3100

iTrader: (1)

Well it doesnt blow All the time. so far its only blown once after the first time and Ive been starting it up and driving it around all day every day since I got it running again.

So the problem is intermittent which is the worst and hardest to diagnose. T-T

Ill see if I can try some of those or maybe clean up those connections and make sure the wires aren't wearing through the rubber or anything.