Fuel delivery problems. Not getting fuel, electric pump not kicking on when key is turned, no start. Suspect relay but can I test pump with jumper wire from battery? Motor is 502 , with Holley injection and merc mefi. Fuel pump I believe is Weldon. Was running good last week

Thanks

Padraig

I see you’re using an aftermarket pump, so the following presumes you’re still using the factory wiring harness. That said, the fuel pump relay is mounted on the ECU bracket. You can jump it there or go directly to the pump with a set of jumper wires. There’s also a fuse block with three fuses in it inside what looks like a data port connector, worth checking for a blown fuse.

However, you may want to check my thread from this past week, I had the same problem and it turned out to be a seized fuel pump that had gummed up. I was able to get it back up and running no prob.

Gen 2 Cool Fuel Pump Seized

Thanks. Just jumped the fuel pump with a hot wire from battery so that is good.

Padraig

if you're running a factory harness check these fuses one is fro the fuel pump

Yes, factory harness, I'll check out those fuses.

Thanks, Speedy.

Padraig

The factory wiring and relay is only designed to handle about 10 amps. Most aftermarket pumps will draw quite a bit more amps.
A friend of mine had issues running an A1000 pump and using the factory wiring/relay. His worked fine for several years, then all of a sudden started loosing fuel pressure above 3000rpms.

Griff, this one does not kick on at all, when I turn the key,, unless I jump it from the battery. Not sure how to test the two relays. I may try replacing them this morning. If I recall they are not expensive. If I recall correctly one turns the pump on and one turns it off

Padraig

Pic of relay.

That doesn't seem right. One relay is all that should be needed for a motor that only has to run in one direction (an electric fuel pump). 2 relays would be needed for something like a trim pump, or a hatch lift, where running a motor in reverse is part of operation.

To test a relay, you need to rig up a little setup for providing 12V and ground to the primary coil of the relay (terminals 85/86), +12V to terminal 30, and a test light on terminal 87 (alternatively, ground to terminal 30, and +12V to the other end of the test light). If the light lights up when 12V and ground are applied to the primary side, then the relay is functioning correctly.

I am not an expert and I am old and have a bad but I am pretty sure that is what Eddie Young told me the two relays did. Motor was a crate motor built by Inovation for Factory 1 racing in 2005. Rebuilt by Eddie Young in 2013. Possibly the two relays were a Inovation thing?

Padraig