Fuel pump runs constantly
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8th Gear
Joined: Feb 2025
Posts: 8
Likes: 1
I've looked through as much wiring as I care to, tested the fuel pump relay socket & have two spade/pin connectors that are constantly hot with the key in the run position.
To keep this short, I've emailed the company that worked on the ECM & he agreed to have another look at it. It ships out today from Oregon to Virginia. I'll keep this thread updated when I get the unit back. Thank you for all your input, Mike
To keep this short, I've emailed the company that worked on the ECM & he agreed to have another look at it. It ships out today from Oregon to Virginia. I'll keep this thread updated when I get the unit back. Thank you for all your input, Mike
Thread Starter
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8th Gear
Joined: Feb 2025
Posts: 8
Likes: 1
Update
Well, the ECM was returned to Keyworks in Virginia last year. He tested it and even posted a YouTube video of it lighting his breadboard tester. Good enough.
Upon installing the ECU back in the truck it had the same symptoms - would only energize the fuel pump when it felt like it. I tried more research came to believe a transistor in the circuit had gone bad.The owner has put up with intermittent starts til recently.
Now, when the key is turned on the fuel pump runs continuously. I confirmed this today by disconnecting the inertia switch & I could hear the pump stop running while the key is in the run position!!
This has been fun but it's starting to get old. I'm standing by my diagnosis of a (still) bad ECM.
Thanks for putting up with me, Mike.
Upon installing the ECU back in the truck it had the same symptoms - would only energize the fuel pump when it felt like it. I tried more research came to believe a transistor in the circuit had gone bad.The owner has put up with intermittent starts til recently.
Now, when the key is turned on the fuel pump runs continuously. I confirmed this today by disconnecting the inertia switch & I could hear the pump stop running while the key is in the run position!!
This has been fun but it's starting to get old. I'm standing by my diagnosis of a (still) bad ECM.
Thanks for putting up with me, Mike.
Thread Starter
|
8th Gear
Joined: Feb 2025
Posts: 8
Likes: 1
Update
Well, the ECM was returned to Keyworks in Virginia last year. He tested it and even posted a YouTube video of it lighting his breadboard tester. Good enough.
Upon installing the ECU back in the truck it had the same symptoms - would only energize the fuel pump when it felt like it. I tried more research came to believe a transistor in the circuit had gone bad.The owner has put up with intermittent starts til recently.
Now, when the key is turned on the fuel pump runs continuously. I confirmed this today by disconnecting the inertia switch & I could hear the pump stop running while the key is in the run position!!
This has been fun but it's starting to get old. I'm standing by my diagnosis of a (still) bad ECM.
Thanks for putting up with me, Mike.
Upon installing the ECU back in the truck it had the same symptoms - would only energize the fuel pump when it felt like it. I tried more research came to believe a transistor in the circuit had gone bad.The owner has put up with intermittent starts til recently.
Now, when the key is turned on the fuel pump runs continuously. I confirmed this today by disconnecting the inertia switch & I could hear the pump stop running while the key is in the run position!!
This has been fun but it's starting to get old. I'm standing by my diagnosis of a (still) bad ECM.
Thanks for putting up with me, Mike.
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