Here's one I haven't seen on this forum. With a clogged fuel filter a truck will run sluggish all the time until the filter is changed. If it's clogged, it's clogged. Right?

My '05 has developed an intermittent problem similar to a clogged fuel filter. It becomes sluggish, max speed 40-50 MPH, pours heavy black smoke, but a few miles down the road it clears up and runs smooth as silk. After changing a number of filters and realizing this was an intermittent problem and not a filter problem, I took the trk. to the dealer and the mechanic said the fuel filter housing, what the filter screws into, "went bad." Had it replaced and, at the same time, had the fuel tank dropped and drained. The mech. claims the tank was clean, ergo validating his claim it was the housing and not the filter.

Here I am 7,000 miles later and it is doing it again. Just in case it was a clogged filter, yesterday morning I had the filter replaced and drove about a 100 miles. I didn't think I was going to get home. For a short period of time, the max. speed was 40 MPH, blowing black smoke, Edge didn't indicate any increase in % of load and, after a few miles, the problem quit and the trk ran fine.

Any ideas or suggestions? BTW: Had the #2-#7 injector wiring replaced about a year ago, so that shouldn't be the problem.

The factory fix on the harness is not a cure all-- the connectors where they attach to the injector are not heavy enough and there is side pull on them. The "Ice Pick" fix is much better. It put a dimple in the connector so it will make contact better. Also be sure you inspect the harness at the passenger side of the alternator. It is tied down with a tie strap and the sharp corner of the FICM bracket cuts into the harness causing a short.

Do you have any codes?

Can you check the injector balance rates?
Check your air filter.

take the EDGE out and see what the truck does

JC1843: No warning lights, therfore, according to the service writer, no codes. Also, the wiring harness appears to be sound.

Kylant: Removed the Edge this morning. Hopefully, in a couple of days I'll know if this was the cause.

Thanks,,,

I had a similiar problem, once I unplugged the bully dog chip the problem solved itself. Took it back to my diesel mechanics and they said it is the power source for the chip, they rewired things and so far so good.

To follow-up, I disconnected the Edge Juice W/Attitude and have driven 3200 miles. Problem solved.

Thanks,,,