Ford F250 Navstar powered problem

[Sitec]

Hi all.

Firstly mods if this is in the wrong place please shift it, and secondly, this is not my usual area, but have a friend in need. A few days ago a fella broke down in his Ford F250 dual cab pickup (Ute here in Australia) just outside our place. Anyway, being nosy I wandered down to see if he was ok/I could help. Long story short, they are a long way from home and his F250 (powered by a 7.3 Navstar common rail V8) will run fine one day with full power and no error codes, but then it will loose power, go into limp mode and then hardly run at all. He managed to get it to crawl into our place in low box and left it with us for a night. He's since collected it and it drove ok (but still lacking power) to a garage where he's left it. They are now headed home in another vehicle and are deciding how to get the Ford home or how to fix it... The problem seemingly has been ongoing and he's changed filters, Cam angle sensor (I questioned him on that as I said it was a crank angle sensor but he was adamant that it was a cam angle sensor), and the IP valve...? amongst other things...

Any ideas peoples? There are not many 7.3 V8 Fords here and most dealers shrug their shoulders as they don't have the software/knowledge to fix it... Cheers for now.

 

[plainjaneFJC]

Is there a special 7.3 that was common rail?

 

[tatanka48]

in the fuel tank there is a "sock"(actually a hard plastic filter) over the bottom of the fuel pick up and a lift pump assembly

as the sock begins to deteriorate it can produce really wonky behaviors similar to what you are describing

on my F-350 the problem didn't occur until it was 16 years old and had over 360k miles on it

it knocked my speed down then up then downer and downer

it managed to get me home butt at only 40± mph and the engine was prone to dying at traffic signals not wanting to start again

that was a long day(Texas Gulf Coast to northern Texas 400 + miles towing a 29' travel trlr running from a tropical storm)

the codes it threw were strange when it threw some

the part/assembly cost over $900 + labour and incidentals :-O

just one more thing to look into

T

 

[Martyn]

I’d check the wiring harness for the injectors. It goes under the valve cover on both sides and is prone to becoming brittle and causing issues.

Lots of threads online about intermittent power issues with 7.3 engines. Here is one example https://www.thedieselstop.com/forums/f24/intermittent-power-loss-241918/

 

[Sitec]

Great info guys. Thanks for the feedback. I'll chat with him later today and go from there. Re common rail, I've not had a close look at the engine, but know its a 7.3 V8 diesel. The owner talked about electronic injectors etc so I assumed it was a CR engine... Guessing theyre more like a Cummins or Land Rover Td5 then with cam operated injectors? Thanks again for the input so far.

 

[Martyn]

Great info guys. Thanks for the feedback. I'll chat with him later today and go from there. Re common rail, I've not had a close look at the engine, but know its a 7.3 V8 diesel. The owner talked about electronic injectors etc so I assumed it was a CR engine... Guessing theyre more like a Cummins or Land Rover Td5 then with cam operated injectors? Thanks again for the input so far.

The injectors are operated using a high pressure oil system, so while they are electronically controlled as far as timing goes it’s high oil pressure that makes them function. The crank case position sensor is notoriously for malfunctioning. Most of us carry a spare around with us, as it’s very easy to replace. If the sensor goes bad it normally results in the engine not running, although I have heard of cases where it will run just badly.

The other critical thing on the 7.3 is the fuel pressure. Low pressure can be caused by a bad electric fuel pump, located on the chassis rail under the drivers seat, and also controller by a return valve located in the valley of the engine. The valve restricts the diesel returning to the fuel tank and in doing so increases fuel pressure. I had to replace both on my truck, the fuel pump was worn out and the spring and o ring in the valve were broken.

 

[IdaSHO]

Don get too far ahead.
best I can tell, we don't even know the model year of this truck.

It might not even be a powerstroke. And early powerstrokes had mechanical fuel pumps.

 

[Sitec]

Don get too far ahead.
best I can tell, we don't even know the model year of this truck.

It might not even be a powerstroke. And early powerstrokes had mechanical fuel pumps.

I spoke to the owner. It's a 2004 7.3 V8 Powerstroke. Cheers.

 

[BBslider001]

I spoke to the owner. It's a 2004 7.3 V8 Powerstroke. Cheers.

They stopped the 7.3 in 2003. Is he sure it's not the 6.0?

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