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Ray M.
Ray M., Ford Master Tech
Category: Ford
Satisfied Customers: 3007
Experience:  30+ years in trade, Ford Master Tech, Journeyman Automotive Tech
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2008 f 350 ford diesel truck will start when cold and run

Customer Question

2008 f 350 ford diesel truck will start when cold and run well but when warmed up will turn over ok but never start. let it cool down and it will startm
Submitted: 3 months ago.
Category: Ford
Expert:  Matt replied 3 months ago.


This could be a wiring issue as things tend to expand when hot and its possible a poor or partial electrical connection is being pushed apart on one of the major sensors so check the connection plug and wiring to the following;

Airflow meter

Crank position sensor

Cam position sensor

O2 sensor

Throttle position sensor

unplug each in turn and use some switch / contact cleaner spray on the pins to ensure its all grease / dirt free

Also worth checking the connections to the fuel pump for the same reason - unplug each in turn and give them a good squirt of switch / contact cleaner - Not WD40

and also unplug and inspect the main power relays and fuses for signs of overheating or corroded terminals - so the ones for the ECU and the fuel pump

And also unplug the wiring loom connections in the engine bay one at time and inspect for corroded or recessed pins.

Customer: replied 3 months ago.
Matt, Your answer is appropriate for a mechanical highly-trained technician. As I read your response, I am totally unfamiliar with where these sensors are located. I think what you are suggesting is that I take my truck to a professional mechanic and let him check these items out. Therefore, I am not satisfied and do not accept your response. Thanks for your time and I request that my payment be returned to my account.
Expert:  Ray M. replied 3 months ago.
Hi with my experience with the 6.0l engine, this a problem with the high pressure oil system, namely an internal leak. Most often a failing connector on the the pump.

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