starts ok, then loses power, then ok up to 30mph...

[macottom]

I’ve got a completely stock 1996 Ford F-350 with a 7.3 liter Powerstroke engine with 301,000 miles on it. It’s been a pretty reliable performer for quite a while but recently a belt tensioner flew apart and I drove it home and ended up getting it a little hotter than usual because the water pump wasn’t pumping. The gauge never got out of the normal range and it didn’t actually overheat. Not to long after that, and possibly just a coincidence, it started doing this weird thing where it loses power, and if I run it over 30 mph it starts to miss. Then it nearly stalls… If I let it sit and idle, it seems to catch up with itself and then it will have lots of power and torque for probably 15 seconds and then it starts the cycle over again. It will bog down, run rough, lose power… Then if I let off of it, it runs fine again.

I did replace a fuel hose that was leaking a little, and the fuel filter in the center top of the motor. I’ve also used a couple pieces of regular fuel line on top of the manifold instead of that expensive OEM (blue) fuel line, so I’ve wondered if I’m sucking air in or the hose has degraded or come apart and blocked something up. I put a relay pump on it a couple of years ago. I’m hoping I’m not looking at a high pressure oil pump or an injector pressure regulator. It acts like this very consistently and I’ve been driving it short distances, but need to get it resolved.

I’m a fair gasoline engine mechanic, but am pretty clueless and a total novice on diesels. I don’t really have a diagnostic computer easily available for this one. Anyone have any ideas?

[WEWILLE]

Is the hpop level full with clean oil? I would throw some gauges on the hpop, but i forgot what the specs were, i will try and find them for ya.

[Beeholder]

I'm having the same issue and came across this old post in my search for an answer, I hope you can help...

[Chop]

Have you replaced the CPS ? This sounds just like mine when the CPS failed,buck and miss,cut off,restart.Pretty annoying but a cheap fix.

[Beeholder]

Yes, I did replace the CPS, right after the fuel filter.

[Buffalo444]

Originally Posted by macottom

I’ve got a completely stock 1996 Ford F-350 with a 7.3 liter Powerstroke engine with 301,000 miles on it. It’s been a pretty reliable performer for quite a while but recently a belt tensioner flew apart and I drove it home and ended up getting it a little hotter than usual because the water pump wasn’t pumping. The gauge never got out of the normal range and it didn’t actually overheat. Not to long after that, and possibly just a coincidence, it started doing this weird thing where it loses power, and if I run it over 30 mph it starts to miss. Then it nearly stalls… If I let it sit and idle, it seems to catch up with itself and then it will have lots of power and torque for probably 15 seconds and then it starts the cycle over again. It will bog down, run rough, lose power… Then if I let off of it, it runs fine again.

I did replace a fuel hose that was leaking a little, and the fuel filter in the center top of the motor. I’ve also used a couple pieces of regular fuel line on top of the manifold instead of that expensive OEM (blue) fuel line, so I’ve wondered if I’m sucking air in or the hose has degraded or come apart and blocked something up. I put a relay pump on it a couple of years ago. I’m hoping I’m not looking at a high pressure oil pump or an injector pressure regulator. It acts like this very consistently and I’ve been driving it short distances, but need to get it resolved.

I’m a fair gasoline engine mechanic, but am pretty clueless and a total novice on diesels. I don’t really have a diagnostic computer easily available for this one. Anyone have any ideas?

i hope you used fuel injection line, not standard fuel line. it tends to not work for long on psd's.

[Beeholder]

My problem was resolved by replacing the fuel pump, thanks for all the assistance...