Won’t start

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Feb 21, 2024 | 06:29 AM

Hsgill6821

Thread Starter

Cross-Country

Joined: Dec 2023

Posts: 64

Likes: 5

From: Central Valley, Cali

Won’t start

Hey there I’m new to this forum thing, have a 97 F-250 HD with the 460 big block (7.5) and it won’t start. Recently purchase This truck and the next day I bought it I noticed it took a little longer to start. I went on with my day and the each day it a little longer to start. The fuel pump would keep running but I would have to wait till it shut off then it started no problem. After a few minutes of starting it, I would floor it and it would cough but go on with my day. Recently it’s gotten so bad that I need to wait a whole 30 minutes for the fuel pump to run. Thought maybe it’s the fuel pressure regulator so I changed it out. No nothing. So i changed the fuel filter. Did not help at all. Changed out both fuel pump (equipped with the 18 and 17 gallon fuel tanks). Sadly that did not help. Just fyi the fuel pressure before all of this was around 30 and still is 30 at the rail. Please, please help me.

Feb 21, 2024 | 06:49 AM

rla2005

Fleet Owner

Joined: Oct 2005

Posts: 20,783

Likes: 1,751

From: Kentucky

Continuous running fuel pump when cycling the key from the Off to Run position is a classic sign of a failing PCM (computer). The computer is programmed to energize the fuel pump relay for 1-2 seconds when cycling the key from Off to Run. There is no active feedback, it's strictly a timer inside the computer. When the computer is failing or failed the timer is never resetting so the fuel pump relay remains energized for some period time. Could be a few extra seconds or infinity/battery runs down.

In many cases the cause is leaking capacitors inside the PCM (computer). Hundreds of threads on this forum about this issue, what to look for and how to try to replace them yourself.

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