I have a 2001 3500 4x4 5 speed with 4:10 rear end. The only aftermarket parts this truck has are as follows- flo pro 4" turbo back, S&B intake manifold, S&B cold air intake, Edge EZ, and Edge insight CTS2 (truck had the EZ when I bought it.). Here are my symptoms...The truck will de-fuel while driving down the road, BUT ONLY IN 5TH GEAR. The problem does not seem to be RPM related because I can fuel all the way up to 2800 (or whatever it is) in 1-4th gear. The truck has absolutely no hesitation to crank, or supply fuel in gears 1-4. The only consistency with the issue is it seems to happen after the truck has been driven for 30 minutes or so and only de-fuels in 5th gear. When I crank it and drive to work in the morning it will run 70 in 5th gear no problems just like it is supposed to. However on the way home if I have errands to run after getting off it will not fuel past 2000-ish rpms *ONLY IN 5TH GEAR* (right around 50-60mph), literally if im feeling ballsy enough I can go faster in 4th gear than I can 5th. The truck is also not throwing a code. I have had these symptoms for a couple of weeks now and it has never happened in any other gear besides 5th. I have put a new APPS, as well as a new lift pump on the truck and it has not fixed it. I have a MAP sensor on the way hoping that maybe my problem is boost related. Everything that I have read about vp44 issues and ECM issues leads me to believe that the problem would be consistent with rpm's regardless of gear, as well as issues with getting the truck started? Has anyone ever had any issues similiar? Any ideas what this might be before I get into the expensive parts?

1 hour ago, Me78569 said:

theres one on the trans as well that the pcm looks at for things.

 

 

That is not vss. That is oss.

tps apps vss oss 

 

 

  

 

lol  you are right

Where is the one on the rear axle? Same on Auto vs Manual? I replaced the one on my trans, I was having a similar issue. It does it less frequently now but only does it after a long drive and seems to be when it is hot (outside air temp and vehicle temp). Usually if I let off it for a bit or cool down like on a long downhill it seems to come back. 

 

@jlongjohn what all have you replaced? Mine only starts acting up when it is hot as well. Temperature and 5th gear seem to be the only common ground for my symptoms.  

Well I've only owned this for a few months now and I have learned a ton about these things and continue to. So I honestly think my truck had a lot of little things that needed attention and some were related, some not, some maybe caused something else that then made something else worse if that makes sense. 

 

So I will just brain dump things, not all related, but easier to remember this way.

 

my truck had vibration, torque converter lock up issue, defueled hard while pulling out or passing or just whenever you didn't want it to, but not all the time. Higher than normal EGT's sometimes riding 1200+ for short bursts when just lightly accelerating (lugging yes but not hard or for long periods). I still hear relays like resetting or chattering in the dash near steering column while driving, sounds like when I put in a new tune with Smarty and the computer resets. 

 

• oil leaks, oil pan and vacuum pump/ps pump seal both replaced.
• boost leak at cold side intercooler boot, replaced. I think I still have a leak on the intake horn/grid heater area. Or the intake plate gasket. 
• Vss on tranny - replaced after seeing so many talk about it and it was on many 2nd gen Cummins fix it lists. Plus it's cheap. 
• Rear driveshaft UV joint was toast, that was 90% of my vibration. 
• Fuel filter on FASS was damn old when I got it, rusty outside and so I said hey let's change that. Turns out it was crap inside too. Also changed the pre-FASS filter. This steadied my fuel pressure a lot and the defueling issue got way better after this and the UV joint were done.
• air filter was an oiled aftermarket, stock air filter box but the sides are cut out on the in-side. That thing weighed like 20 lbs and looked like coal dust was dumped in it. EGT improved by ~200 degrees after I replaced with a standard off the shelf filter. 
• Turbo output v-clamp Oring was dry and flattened, cleaned corrosion off and put in new oring. Boost improved by about 3-5 psi. 
• Oil changed, using Rotella T6 and Napa filters. 
• All grounds I can find cleaned and reattached, cleaned battery posts and clamps. All have dielectric grease applied. Also removed and cleaned and reinstalled the pcm connectors. 
• Have a BD noise isolator installed for now, will likely remove.
• Tested myself and shop tested my alternator. Added a heavy duty (battery cable) ground to alternator bracket. Noise improved. I currently do not have torque converter lock up issue. 
• Added the trans fluid additive everyone recommended for shudder issue. 
• Rerouted the ground away from alternator. Also checked and cleaned and greased all the plastic factory snap together connectors for the ground cables. 
• Specific mention, cleaned the ground strap from PCM to firewall. 
• Inside fan speed resistor pack was bad, only had top 2 speeds and I believe this caused a lot of my electrical noise. Replaced with new. 
• New blend door coupler, got aftermarket metal coupler to replace the plastic. 
• 4x4 vacuum actuator on front axle replaced. 
• New power steering pump, did that when I had the vacuum pump out for the oil seal, the PS pump is cheap and why not when it's out. Also flushed and installed new PS fluid. 
• Tried many different Smarty tunes and revo settings. Currently liking SW5 TM4 T3 D4
• Replaced APPS with new Timbo. Had dead pedal when I bought it. 

I think thats it, might have forgotten something. Not in timeline order. Some done separately some done at the same time. 

1 hour ago, Me78569 said:

tps apps vss oss 

 

 

  

 

lol  you are right

 

Don't you even start with that apps and tps bs......

 

 

Sensor is on the top of the rear axle.

I think we all went through most of that and some, don't feel bad in the end you get something you know and hopefully cam rely on. 

Thank you, no worries here. I have had tons of vehicles over the years and I always treat each one like a project. I do all my own work and like that I know what works and what doesn't and that after I do some work that it's on me. Usually when I have trusted others with repairs it doesn't turn out well. I know many of us on here probably live with Murphy. I find it a challenge and get a lot of satisfaction from fixing issues. I hope you all enjoy your vehicles as much as I do. 

 

My my list of to do's is large, but it's always something to look forward to.

• New turbo, maybe 351ve, looking for good spooling down low for daily driving and towing with an exhaust brake
• need to do the CCV MoparMan rerouted and clean the radiator and front end. 
• Going to replace heater core and open the hvac box and clean
• going to refresh the whole ac system, compressor, expansion line, evaporator core, accumulator
• new control arms to fix caster for lift
• new steering and front axle refresh
• quadzilla v2 with iquad
• new doors, bottoms rusted out, and cab corners. PA Truck special
• check valve lash and see if it is/was studded
• front driveshaft rebuild
• lock up switch
• step bars, it's a jump to get in
• possibly a sump, draw straw must have been installed well haven't had any issues at low fuel levels
• stainless brake lines
• new shocks and steering stabilizer
• paint body and linex the lower 1/4 of truck
• por 15/chassis saver the frame and under carriage
• add a muffler, sorry too loud, maybe do duals to keep flow high?
• headlights, prob do mishimotos
• led all bulbs in truck
• aftermarket air filter setup, round filter of some sort...
• check dowel pin and front cover and tappet cover
• prob missing some but it's fun to dream

Its good to have a 2nd vehicle, just in case...

I think I finally located the culprit. After more and more research I started questioning the Edge EZ on the truck which has a manufacture date of June 21, 2002. I pulled the chip off, reset the computer (disconnected both negative battery leads and turned the key on), put it back together, and then opened it up for about 40 miles of highway and it ran like a top. One of the places that the EZ was plugged into was the map sensor. All of these things combined lead me to believe that is the reason the new MAP sensor fixed the issue for only a short period of time as well as why the truck was throwing no codes.