I have a 99 F-350 Crew Powerstroke 7.3. While towing a 12 foot trailer up a grade the truck hickuped a couple of times and then slowing lost rpms until I was on the side of the road idling. Truck idled fine but on reving the engine seemed doggy. Would not go forward or in reverse. Changed the fuel filter, no joy. Late next day truck started and drove fine. It still will not develope full power. Feels like 60% or so. Won't blow much black out the tailpipe. No tuner all stock. Everything under the hood is there and hooked up. High pressure pump reads fine. Drives around town fine but under a load not so good. Any ideas?

 

My boss has an 02 f250 that would drive fine and then just loose power. If it was shut off and restarted it would run OK for a little while and then loose power again. It would do it intermittently and when I put a high pressure gauge in to watch the injector pressure it would be at 1500 to 2500 driving and then just drop to 400 to 500. It was the HPOP in his truck. I had already replaced the IPR and ICP and cleaned the EBP sensor and feed pipe.

 

My powerloss is consistant. It seems to always be at 60% power or so. The HPOP reads fine all the time. Another source is pointing the finger at a screen in the fuel tank? Is there one? I can't seem to see anything mentioned about it in the service manuel. Partially clogged "Frank" says it will starve the pump under loads. Does this sound right?

 

I know the 02 has a thing in the tank that is a combination screen and warm fuel mixer. It mixes warm return fuel with the tank fuel going into the line. I don't know if the 99 has the same thing. A lot of people on here have talked about just putting a dip tube pickup and eliminating the mixer unit but if you do it would be wise to put some kind of filter in line to protect the pump.

 

You keep stating that the high pressure oil pump reads fine... How are you measuring? also a stock truck will have almost no smoke without a tuner so that isn't a good judging of power. Have you checked fuel pressure? Have you checked oil level? Do you have access to a scanner like AE?