Thanks in advance for any advice on this. I've got a 1997 International FedEx parcel truck with a T444E. This piece has 250,000mi and 19,xxxhrs of hard use. It has a severe lack of power with a random miss/stumble, and what sounds like a fuel knock. Heavy smoke out of the tailpipe, greyish-white, on accel through third gear, it clears up after that. On flat ground it will make it to about 50mph in the span of two miles. Last year I replaced #1 injector for a dead miss and all 8 glow plugs because 7 were open and they had been ether starting the truck for quite a while. At that time it was suggested to the customer to replace all injectors because it was unknown if they were original, they declined. The camshaft position sensor has also been replaced for a stalling issue. Using a pro-link I have run a buzz test and cylinder contribution. Passes buzz test, fails #2 and #7 on the contribution test every time, sometimes fails #3 and #4. The only inactive code retrieved is for baro pressure (I don't have the code number in handy at the moment), though that code has been present in the past prior to the running issue. I have run the truck from a container of clean diesel between the seats to eliminate the fuel lines/pickup/tank with no change. The truck starts and idles great, hot or cold, though it will stumble if rpms increased with no load. The actual and desired ICP are within +-200psi of each other at all rpms/loads. The truck has been poorly maintained for as long as it's been coming to me, the customer does his own Pm's and the oil changes and fuel filter changes are few and far between. I'm leaning towards suggesting replacement of the other 7 injectors, but would like some feedback to make sure I've covered all the bases.

Evan Glynn
Technician
Kurt's Auto & Truck Center
Rockford, Illinois, USA