Join Date: Jan 2019
Location: Woodburn, OR
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Hesitation under load..fuel starvation??
I picked up my first cummins a few months ago and this is my first diesel I have every owned. The pickup is a 2001 ext cab 2500 5spd with 140k miles. It has a Raptor RP-150 lift pump and the rest of the motor is just about stock.
Anyway on to the problem..every now and then I haul a big tex 14lx dump bed trailer with a good sized load of dirt/gravel which ends up being about 10-12000lbs or so. On any incline going 50-60mph down the highway, there would be a very quick and very abrupt cut out from the motor (it happens in the blink of an eye but it shakes the whole truck). There is no loss in fuel pressure, it remains steady at 14-15psi. After this hiccup the truck keeps on chugging like nothing happened. This would happen once a month or so. However, last weekend, I drove about 4 hrs towing my cherokee in the dump bed trailer and 3 hrs in, the truck started up again on the hiccuping problem. The most common it occured was within a 3-6 minute window and it is all dependent on pedal position and load on the motor. I pulled over, took the jeep off thinking that a lighter load would help and it did not. I then ditched the trailer at a friends house, drove the truck around the block and now even with no trailer, going up a hill winding her up in the top of 2nd she'll slam me with a hiccup.
It seems like anytime under high fuel consumption/load there is a problem. However, I just took the truck out, warmed it up, ran through the gears at WOT and it was fine. Some hills are fine and others are not. It seems to be fairly random, yet consistent when the truck is under load. There is no white or black smoke either and the truck never has a hard time starting or a rough time running. It also does not matter if the truck is fully warmed up or just pulling out of the driveway, if I really beat on it up a hill it will most likely happen (sometimes not though). I have changed the fuel filter, TPS, re-calibrated the TPS and still nothing seems to help. I also hooked up my scanner and there are no current or past codes showing up and no check engine light.
I am thinking its either the VP Pump or ECM...what do you guys think?? Any insight would be greatly appreciated!!