Two weeks ago I noticed my 99 E350 box truck would stumble on the highway under acceleration from time to time. Most times it would be fine and accelerate just way it should but other times it wouldn't and it began to happen more frequently. I had to take a trip over the weekend to Charlotte which is a 1000 miles round trip for me. Right after leaving Charlotte the radiator took a dump and started leaking bad. The temp gauge started rising slowly but I assumed it was due to the fact that I was starting to hit the mountains and it was during the hottest part of the day. I'm have a small moving business in Pittsburgh pa and Friday I had moved two customers and then had to go to my third customers house who I was moving to Charlotte. I left Pittsburgh on 3 hours sleep at 2am and had driven straight thru to Charlotte,510 miles, Unloaded furniture and got back on the road for trip home, another 503 miles, all on 3 hours sleep,long story short I was dead tired so I wasn't exactly paying as much attention as I should have been when I first noticed it rising, again assuming it was due to the mountains,well when I looked again it was up to the red but I was on a climp up a mountain with no shoulder or room to get off the road safely with a box truck so I had to drive another half mile to a safe spot and my oil pressure tanked so I shut it down and coasted down to a safe place with enough room to get my truck off the road. I ended up getting it home after letting it cool a few hours and having a tow truck driver/mechanic check it out. My oil pressure came back when we restarted it and I drove it 300 miles but the original stumbling under acceleration issue returned with with me still 100 miles from home and got worse. If I let it sit 5 minutes it accelerates just fine,runs like a dream for 5 minutes and then stops accelerating again and wont go over 40. If I floor it stumbles worse. It never stalls or shuts off, it sounds great at idle and as I said I pull over,wait 5 minutes and boom it runs like new again. So is it a case of the original cause of the stumbling getting worse due to putting another 1000 miles of wear on whatever part or problem that was causing the problem in the beginning or is it due to it over heating? Sorry for such a long post but wanted to get the full background out there since it help in figuring out the issue.

 

For starters I would check fuel pressure. You did change the fuel filter right? Does your E series have a steel or a plastic tank?

 

Ill check to see if its a steel or plastic tank, I actually heard about the delamination. So while Im waiting to see what other members say Im installing a new radiator today,new fuel filter, new cps, new thermostat, change oil again even tho I just changed oil and filter last week, checking out clutch fan and while Im at it im going to replace belt,hoses and flush the rest of the coolant system. May throw new brakes and rotors on it too since I could feel the brake pedal pulsate going through the mountains. Id like to know if wix makes a fuel filter for this engine since they also make oil filters for it. Ive always been loyal to Wix filters ever since I had the filter element actually collapse and stop oil flow on a Fram filter on a car a few years ago.

 

Its a box truck/cut away chassis so I'm thinking its not the stock ford tank, not sure the size but it took $150 to fill at $2.89 a gallon so roughly a 52 gallon tank.