I had a post a couple of months ago about this E350 van I purchased with the 7.3. It would leave me stranded every few weeks and I replaced the injector oil pressure sensor and the camshaft position sensor.

This truck has a intermittent running problem that cannot be pinned down to hot or cold.

It runs and idles well but sometimes during acceleration it will start to flatten out and smoke out the exhaust. Giving more accelerator pedal powers through the flat spot and the truck runs smooth. It does not do it everytime. It does it hot or cold, wet or dry, city or highway,

If this was a gas engine I would be replacing the fuel pump or checking a fuel starvation issue but the white smoke tells me that it has unburned fuel.

A cylinder contribution test passes fine. I monitored engine data with a Snap On Verus pro and compared oil pressures with another 03 7.3 I have and they are too close to the same.

It starts fine, no issues there. It may take off great one time and buck and smoke the next. I swapped out the throttle position sensor with the other 7.3 and no change. I swapped out the injector control module and no change.

I've thought about injector Orings but I would think the problem would be consistent. I've changed engine oil, checked fuel pressure, changed fuel filter, and drained the fuel system to be sure no water is in the separator.

This engine was rebuilt about 30k miles ago. If you floor the accelerator in park it will rev up, flatten out, smoke and buck for about 2-3 seconds, and then take off like normal. I pulled a trailer with it a couple of days ago and wasn't impressed at all. I have a 6.5 GM that seems to have more power than this.

I thought maybe a sticking injector and I added a half gallon of two cycle oil to the fuel to see if that might help. It hasn't.

It just seems like it is flooding at a certain rpm and clears itself after a couple of seconds.

There are no codes being thrown in the pcm. I am at a loss.

Any suggestions?

 

Is this a box van or regular van?

The box van had a steel tank that is known for delamanation to the crap they lined the tank with and clogging the fuel pickup screens in the tank. The standard tank can also have clogged pickups in the tank but it is more of a given with the box vans.

If it's not fuel the two things I would check first IPR ( injection pressure regulator) and UVCH ( under valve cover harness).

The IPR controls the high pressure oil to the injectors. It is a magnetic valve that can get junked up and cause intermittent issues.

The UVCH is the harness that carries the injector fire signals to the injectors through the valve covers. They can get loose at the big connector under the valve cover and cause intermittent issues.

Do a search in the 99-2003 7.3l section under the Diesel tab on this forum or post a new thread there and get all the links and picture you ever desired.

I can't do my due diligence as an FTE member with linking stuff right now because I am on my smart phone but if you head down to the 7.3 section you will definatally get straightened out.

 

Thanks for the reply. I will look there. FWIW, this was a incomplete vehicle and led most of its life as an ambulance. It was returned to the facility that converted it and they removed the ambulance box, put a back on the cab, built a flatbed, rebuilt the engine, front end, and other components and used it for a parts chaser until I purchased it from the owners estate. The fuel tank is plastic.

The IPR and UVCH will be a major pain because it's a van. I believe I will have to remove motor mounts to lower engine to get valve cover off. Not looking forward to the task and was hoping someone was going to give a magic cure that avoided the work.