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Discussion Starter · #1 · (Edited)
1999 Super Duty, 7.3, manual tranny. On tip in (when accelerating after a shift) there is no power. I mean zero power like no fuel, and the truck begins coasting to a stop. Take your foot off the throttle and push in the clutch and it will idle just fine. If I baby it there are no issues. It cruises just fine. It idles just fine. There are no codes other than one for windshield wipers or some such crap.


I haven't found many threads with these symptoms. The one I found pointed to a wire worn by a bolt head on the driver side valve cover (MAP sensor wire?). My wire loom was worn, but the wires were intact. After moving the wires around to inspect them and fix the loom it ran fine for a short while. I did replace the throttle 5 or 6 years ago.


I hate to start throwing parts at this, any ideas?
 

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Welcome to TheDeieselStop

I'd suspect the accelerator pedal. Possibly the Idle Validation Switch portion of it.

If your scan tool can watch parameters, set it up to monitor IVS status and AP position and see what happens when you mash the pedal. The IVS should switch nearly immediately as you push the pedal and the AP position value should go up smoothly. If you can't do that with a scan tool, you can do a similar thing with a multimeter set to ohms, checking resistance across the pins of the IVS and AP position sensor.

Good Luck
 

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Discussion Starter · #3 ·
You nailed it! Thanks so much for your help!

New accelerator pedal and the old girl runs perfect!

Damn, I'm talking in exclamation points again... I love this truck!
 
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