03 Cobra Pumps wont Prime

[GTCobraClone]

Hi guys, its been a while since Ive been on but have an issue I could use your help on. Im helping a friend with his 03 Cobra. He was driving around a few months ago and the car just dies on the road. He got a code(not sure which one) and he was told he needed new pumps.

Fast forward to las week, he changed the FPDM, Inertia switch, and the CCRM. Car has a boost a pump that the previous owner installed and the wiring is a bit of a hack job. I went over and dropped the tank, installed two new 340lph pumps. Hoses and everything looked good.

We put everything back together and the pumps wont prime on ignition. Checked fueses on engine bay and BAP and they are good. Confirmed power to connectors all the way to fuel tank connector and its getting 12V. I fed 12 V directly to the pins on the fuel tank harness and the pumps run.

Not sure what else to look for.

 

[01vert]

You answered your own question if you have power on the wiring harness at the pump hat and applying power at the pump that runs. The connector has an issue. You could also pull the harness at the other end and see adding power to the end near the fpdm will energize the pumps. Looks like the connection between the two connectors at the pump is the issue, based on your explanation. A pin back out?

 

[GTCobraClone]

You answered your own question if you have power on the wiring harness at the pump hat and applying power at the pump that runs. The connector has an issue. You could also pull the harness at the other end and see adding power to the end near the fpdm will energize the pumps. Looks like the connection between the two connectors at the pump is the issue, based on your explanation. A pin back out?

So I also tested with the connector plugged into the FPDM. There was power going in and out of the FPDM (12V). So basically power at FPDM both ways, power at the pump harness at the tank. Looks more like there is no signal being sent for the pumps to prime.

BTW

If I run the pumps directly to test, should fuel pressure build in the line? We were getting zero fuel pressure when testing the pumps.

 

[DSG2003Mach1]

Running the pumps directly should build pressure before too long

 

[Bullitt1448]

If the pumps are running and you have fuel in the tank it should build pressure

 

[GTCobraClone]

If the pumps are running and you have fuel in the tank it should build pressure

Ok, so time to drop the tank to see if one of the hoses came loose. We ran the pumps a few times to see if we got any pressure at the fuel rail and nothing.

 

[03' White Snake]

PATS light on?

 

[GTCobraClone]

PATS light on?

No, thought about that but light is not on

 

[DSG2003Mach1]

PATS light on?

if PATS were an issue it wouldnt be sending voltage out of the FPDM - shouldnt send power out the CCRM even is my understanding.

the pumps running and not building any pressure at the rail when directly powered says there's something else going on here

 

[blownfox]

I'm guessing its the plastic fuel line going from the pumps to the top of the fuel hat. They have been know to brust.

 

[01yellercobra]

What brand of pump did you go with? Some of them use a 5/16" outlet instead of a 3/8". Unless you use the correct hose it won't seal and will never prime correctly.

 

[GTCobraClone]

What brand of pump did you go with? Some of them use a 5/16" outlet instead of a 3/8". Unless you use the correct hose it won't seal and will never prime correctly.

Sorry for the late reply, had to go in for an ankle surgery.

So the pumps are Deatsch Werks. We removed the BAP and rewired a new connector to the FPDM. My friend says that when he turns the key the pumps don't prime but he heard like two clicks or thumps from around the fuel tank area.