Thank you to 914 World and New Problem- Fuel System, Fuel System Options

[Oregon74]

First- without the help of Admin Andy and Timothy nd 28- my 1975 1.8 L jet would not be on the road. Thank you to everyone who helped me.

NEW ISSUE I NEED HELP FINDING- WHY CAN'T THE ENGINE CONTINUE TO RUN?

The engine will start. (I was having a problem with the ignition not turning the motor over- but I think I solved it with a fuse and a relay problem). Now, she starts every time, but then stops after a few seconds. It appears either my fuel pump is out or I'm not getting enough electricity to the pump to run it.

I have installed a MSN fuel pump. It is high presure and worked perfect out of the box. I put about 2,000 miles on the car before this mystery started.

I've checked the in-line fuel filter and it seems fine. (I do live in Southern Oregon where during the winter the area is forced to run oxigenated fuel that is known to cause problems with older cars- but since she starts just fine I think my injectors are ok.)

I've pulled the relay apart and all contacts seem to hit just fine.

My questions:

1. Could a new fuel pump go bad this fast?
2. If I'm not getting enough electricity, or have a bad end, where in the world do I find the wires in the engine bay? The pump is connected with a brown and a black (ground) wire.
3. Could it still be the relay?

Thanks in advance of to everyone who might chip in advice. I am not experienced checking voltages- but am willing to learn.

The problem with this car is: I've got the body in great shape, put a new interior kit in, and have thought about selling it to finance either an SC or a motor for my 365c, but I'm really starting to love this little car. Or as my wife calls it: The Hot Wheel.

Thanks,

JAA
Oregon

[timothy_nd28]

Just to keep everything straight, lets review what has been tested so far:

By applying power straight to pin 88D,your car runs with this configuration, proves that the wiring from the dual relay to the fuel pump works...(above pic)

This test applies power to pin 88a, and you physically moving the AFM flap by hand, turned on the fuel pump. This proves that the AFM fuel contacts are functional, so far so good...(above pic)

This test applies power straight to pin 88z. Physically moving the AFM flap with the ignition on, had a result of no fuel pump action. Which made me home into the actual coil part of the dual relay (above pic)

Forcing the coil, we applied 12vdc at pin 86c. With the ignition on, and forcing the AFM flap open, no fuel pump action

Forcing the issue "part 2", we kept 12vdc on pin 86C but also added a ground on pin 85. Test result was (ignition on, flap deflected), fuel pump did turn on. This made me believe that we had a bad ground