Hi everyone,

I'm encountering some troublesome issues with my 1988 Ford F350 (7.3L DSL) and could really use some guidance. The engine idles too high, remains running, but at an excessive speed. Additionally, it only starts with the assistance of starter spray and can be turned off only by pinching the fuel line before the pump. Interestingly, when the key is removed, the engine slows down but remains running.

I suspect these problems might be related to fuel delivery or high pressure pump adjustment issues. Does anyone have experience with similar symptoms or know where I can find manuals or guides for adjusting the pump? Any insights or advice would be greatly appreciated.

Thanks in advance for your help!

Greetings from Germany!

 

If you are sure the throttle linkage is not binding and the throttle return spring is not broken OR floor mat not stuck under throttle pedal then we need to go deeper.

I have see a similar problem when gasoline was inserted in the fuel tank instead of diesel fuel. Does the fuel have a gasoline odor?

 

Thanks for the advice! I'll definitely try getting fresh diesel from the gas station today, as the fuel in the tank could indeed be quite old. I've already disconnected the throttle linkage, but unfortunately, it didn't make any difference. Also, just to note, the lever on the high-pressure pump is at its minimum position, so theoretically, it should be at idle. After filling up with new diesel, I'll give it another go and see if there's any improvement.

Will keep you posted! Thanks again for your help.