My truck and a friend of mine both have the same 2001.5 ho trucks. His has about 50000 and mine has 97000. Both trucks have the same random stumble in higher gears. He took his to the dealer and they put new vp, lift pump, and what else I'm not sure of. It didn't help a thing. They then told him it was probably in the wiring harness and that wasn't under warrenty! I took mine today to a certified bosch dealer rebuilder, put a computer on it and took it down the road. Finally got it to stumple some with computer hooked up and it showed absolutely nothing wrong with the truck. SURELY someone has figured this out. It's ashame a great truck can be ruined by a simple problem like this. If I can't get it fixed I think I'll go back to a 12 valve simple setup. At least they will run with just one wire hooked up! Any help would be appreciated.

 

Try some injector cleaner. My fathers Ford diesel had a studder at 60 mph he never knew of because he only drove up to 50 mph in the small town he lives in. The injector cleaner cured his studder..........

 

Head for Wally World, Attwoods or Tractor Suppy and get ya a bottle of Power Service. This stuff works wonders for the stumblys and the blub blubs. They even have a winter blend to help prevent gelling. Mine got a stumble a while back and I tried this stuff, 100 miles later it quit and is back to smooth purr. Plus one 32oz. bottle lasts for 100 gallons

Aaron

 

I think we might have narrowed it down to the superchip box we are running. I think these superchip boxes are supposed to be a rebadge ez but not sure. The other truck took the little timing box off and the stumble stopped. Has anyone had this experience with the small timing boxes? Do the bigger adjustable boxes have this problem to? What big boxes do timing and fuel. I have a tst pm3 but it doesn't do timing I don't think. Without timing these trucks are kinda slugs out of the hole. Any help would be appreciated. As to injector cleaner I just put new injectors in and it didn't change a thing.

 

I have sent a email to superchips to see if I can get any response from them. If this is a problem with this particular product people need to know about it. A local guy deals in them and has sold alot of them around here. They need to be got off of trucks if this is a problem with them. If anyone else has had this problem please respond and maybe something can be done about this .

 

I have the same thing with my truck. I have a TST PM2. Going down the interstate out of the blue it bucks then nothing for maybe a month? It is just annoying empty but damaging with 20000 lbs. of nursery stock behind me!

 

I have been experiencing the same problem with a EZ box. I don't believe it is the box on my truck. I took a trip out to OK and experienced the bucking pulling my 5th wheel. I disconnected the EZ and drove 700 miles without it and still had the same problem. Have you tried resetting your APS. You can find the directions in the Tech section. It may help with your problem. After resetting the APS my truck did not buck as bad, but I haven't pulled my 5th wheel yet to see if it is cured. I understand the disappointment, my truck only has 71,000 miles. Hope this helps.

Rob