Engine stalling no matter what we do?

2004 FORD F-150
220,000 MILES • 5.4L • V8 • 4WD • AUTOMATIC
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TANNER_GOD10
I have the 5.4 triton 3v and when we got the timing was out so we fixed that and it ran good when first starting up but once it gets up to idling temps it stalls when shifting into anything besides park, We were thinking it was the fuel pump but it is also getting bad with misfires even after replacing the coils and all that. I'm just wondering what could be causing the problem with the misfires and also the stalling when at idle temperatures?
Mar 31, 2025 at 8:36 PM
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STRAILER
  • ✓ASE Certified Mechanic
  • 54,503 POSTS
  • ASE Certified Mechanic
It sounds like the TPS sensor is bad or you have a vacuum leak, these engines have a classic vacuum leak at the rear of the intake manifold. Here is an image of it below. Also, this guide should help also, we should run the codes to see if any are stored.


https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

and

https://www.2carpros.com/articles/stall-at-idle

Here is the vacuum hose in question. Check out the images (below). Let us know what you find.
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Apr 1, 2025 at 6:15 PM
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