Electrical Gremlins took over my fuel wiring

[Erick]

Dude you rock... thanks for the patience. I'm going downstairs again. BRB.

Edit: Ok, I get power on the small gauge red wire (terminal 30). No power in 87b tho, even with the relay connected.

For future reference, on my car the 87b wire is violet/green.

Edit2: I used a wire to power up the 30 to the 87b and I still didnt hear the pump go on... I checked with the test light and the 87b was recieving power while I had bypassed with the wire.... so I had a good contact there.

- Erick

[Erick]

Anyone?

[E304life]

I have been busy the last 2 days so I am just know getting a chance to log in.

It is starting to get a little tricky so hang with me. The difference in your wire colors tells me that your car is considered a late production car.

Jump the relay again...

Next check the power at the fuel pump use the violet/green wire, I would be a good ideal to check power at both fuel pumps (main is on passenger side, transfer is on the drivers side.) the wire color is the same for both.

If you are getting power at both wires then you have two options, get a fuel guage and check fuel pressure or get a ohm meter.

To check ohms, disconnect both fuel pump connectors and check ohms between the brown wires and a known good ground. Reading should be less than 3 ohms.

If this is too complicated locate a known good crank sensor and swap it out.

Report back with your findings.

I will try to check back on thursday if work is not too busy.

Btw that left feld coment about the crank sensor is because I got burned on a no start on one of these old dogs a few days ago...it was a crank sensor.

[Erick]

I have been busy the last 2 days so I am just know getting a chance to log in.

It is starting to get a little tricky so hang with me. The difference in your wire colors tells me that your car is considered a late production car.

Jump the relay again...

Next check the power at the fuel pump use the violet/green wire, I would be a good ideal to check power at both fuel pumps (main is on passenger side, transfer is on the drivers side.) the wire color is the same for both.

If you are getting power at both wires then you have two options, get a fuel guage and check fuel pressure or get a ohm meter.

To check ohms, disconnect both fuel pump connectors and check ohms between the brown wires and a known good ground. Reading should be less than 3 ohms.

If this is too complicated locate a known good crank sensor and swap it out.

Report back with your findings.

I will try to check back on thursday if work is not too busy.

Btw that left feld coment about the crank sensor is because I got burned on a no start on one of these old dogs a few days ago...it was a crank sensor.

Ok I would like to clarify some things before I move on to make sure we're on the same page.

The pump that's not getting any power is the one on the driver's side. I was considering that one the main pump. All my testing was done on that pump, and not the one on the passenger side (below the rear seats)

Anyhow, onto today's findings:

I jumped the relay and went down to the driver's side pump. Finally it got power, although the pump itself wasnt on.

I went to the pump on the passenger side, under the rear seat, and found two connectors, a small one with 2 ports and a bigger one with 3, both carrying the violet/green wire. On the 2 port connector, I got no power out of it (I am assuming that might be the connector that goes to the fuel pump on the other side)... because when I tested the 3 port connector I got power from the violet/green wire.

Attached is an image of the connectors so it's clarified. I'm starting to believe that it might be this crank sensor you're talking about.

- Erick
PS: I apologize for rushing, I understand everyone has their own life to take care of.

[Erick]

I just did some research and I found that M10s dont have crank reference sensors.

[E304life]

Your right about the crank sensor, I looked into it and found the crank signal comes from the triger wheel on the distributor then to the ignition module then to the fuel pump relay.