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View Full Version : GEN 4X Coyote fuel pump help



LSX
04-23-2026, 06:12 AM
Hey everyone.

Hopefully someone can help me with this. I am not getting power to the fuel pump with the key on. I have everything connected correctly and tripple checked everything. The only time the fuel pump energizes is when I initiate a start command and have the clutch depressed. Then the fuel pump will power on for a couple of seconds during the start sequence. (starter is disconnected)

I have good voltage for the trigger wire that goes directly from my ignition switch.

I have good voltage for the start wire that only is active when i press my start switch.

The PDB has voltage and I can hear the throttle body activate on ignition run. I have also verified the relay at the PDB is working and jumped the terminal to verify the fuel pump will activate.

Everything looks correct, however the PCM is not activating the fuel pump for some reason with key on.

I have not attempted to actually start the engine. Also the MIL light is not active with key on or start.

Any ideas?

LSX
04-23-2026, 08:39 AM
Just spoke to the ford tech line and they told me this was all accurate and I should only be getting fuel pressure when cranking. Guess ill fill her up with fluids and give it a try this weekend.

Blitzboy54
04-26-2026, 07:48 AM
Hey everyone.

Hopefully someone can help me with this. I am not getting power to the fuel pump with the key on. I have everything connected correctly and tripple checked everything. The only time the fuel pump energizes is when I initiate a start command and have the clutch depressed. Then the fuel pump will power on for a couple of seconds during the start sequence. (starter is disconnected)

I have good voltage for the trigger wire that goes directly from my ignition switch.

I have good voltage for the start wire that only is active when i press my start switch.

The PDB has voltage and I can hear the throttle body activate on ignition run. I have also verified the relay at the PDB is working and jumped the terminal to verify the fuel pump will activate.

Everything looks correct, however the PCM is not activating the fuel pump for some reason with key on.

I have not attempted to actually start the engine. Also the MIL light is not active with key on or start.

Any ideas?

Sorry, I missed this. Yup totally normal. Also FYI, because the pump only primes first start can take longer than other engines. Fuel has to creep it's way up the rail. If you have a power supply or something you can direct power the pump so it primes faster the first time.

After that it will start right up. Also if you have technical question better to put it on the Roadster forum. It gets a lot more traffic than this one does. You will get a faster response.

LSX
04-26-2026, 09:34 PM
Thanks for the heads up bud. Got her fired up this weekend! And you are totally right. It took a long time to get fired up. Thought something was wrong. Once I cracked the fuel line open and verified fuel it fired right up! Sounds amazing. Thanks bud.

hennessyVV
04-27-2026, 12:06 AM
Which fuel pressure regulator are you using? Also, does it take long to start after letting it sit for a day?

LSX
04-28-2026, 05:34 AM
I’m using the one factory five provided. From what I’ve noticed it does seem to take a couple of seconds before firing up after sitting for a day.

Railroad
04-28-2026, 09:02 AM
It kills me to watch first start ups, without letting the fuel pump cycle, before engaging the starter. "on EFI engines"
grind, grind, grind!
TURN THE KEY TO ON, WAIT A FEW SECONDS, BEFORE STARTING.
Now I feel better.

LSX
04-28-2026, 08:17 PM
If you bothered to read the post the fuel pump doesn’t engage until you attempt to to start the gen 4 coyote. Don’t ask me why.. that’s what Ford performance designed.