Hi everyone,
Three times this summer I've had the problem that my truck lacked power after shutting down for a short period (about 15 minutes), then starting up again. First time was on a roadtrip to Yellowstone, about 1,000 miles into the trip we stopped along a river for a bit, then after starting up and on the road again I didn't have power, could barely get the truck (with cabover camper) up to 35 mph on flat ground and the turbo gauge showed no boost. switched fuel tanks (fuel from different stations in each tank, no improvement). I thought maybe water in fuel or clogged injectors, so I drained the fuel filter (no water) and filled the filter with ATF with no improvement, so we limped a few miles to a campground for the evening. The next morning the truck started up and ran great, so we continued along to west Yellowstone and I installed a new fuel filter and called it good.

About a week and 900 miles later same thing happened while driving through Wyoming - stopped for a bit to let the dog out, and when I started up, no power, no boost, max speed about 35 mph while flooring it. Pulled over, checked filter, added ATF, and started and ran perfectly for the rest of the trip.
Both times were during travel days with a few hundred miles driven before the problem happened. Also, I didn't notice any difference in the exhaust color when power was low, but I am noticing a bit more black exhaust while under load than I remember seeing before the trip.

Fast forward three weeks and 1,500 miles, back home and after a day of fishing I was leaving the boat ramp after washing down the boat (truck idled a few minutes while loading the boat on the trailer, then engine off for 20 min while washing boat), I had no power again, this time with a relatively cool engine. Pulled over after about a mile, shut engine down, checked for ATF but didn't have any to add to filter, checked oil and transmission fluid level, all good, started up thinking I was going to limp home 15 miles doing 30 mph, but to my surprise it had full power again and ran great.

Some more information: IP and injectors replaced in 2014, less than 20,000 miles on them, no starting issues or air getting into fuel lines that I can tell, C6 transmission with no known issues, Banks turbo installed 2014, gearvendors installed 2014, total miles on truck 180,000, I used Diesel Clean on about 50% of fillups.

What could be causing the intermittent power issues? Fuel filter would be an obvious answer, but I replaced that. Injectors next considering the first time it sat overnight with ATF in the injectors, but the second time improvement was immediate and the third time I didn't remove the filter, just shut down and checked fluid levels.

Any ideas?

Thank you,
Jan

 

Lets narrow this down:
First, it's between the fuel tank and IP. The injectors won't do this; they only squirt the fuel that the injector pump gives it. If one sticks open, you'll get a rough running engine and a lot of smoke. You can't really have them stick shut, because the pressure from the IP will simply increase until it pops open... basically.

If you are effectively not getting enough fuel to get full power, but no surging, I would check the fuel tank and make sure something's not clogging the intake. It might be worth investing in a fuel pressure gauge and connect it up to the fuel filter, that way you can see what's happening in real time.
The fact that it 'corrects' itself after restarting makes me think crud of some sort that gets dislodged.

Note that it's probably not the low-pressure transfer pump; once the engine is running, the IP will /pull/ fuel if it has to. It has a small sliding-vane positive displacement pump inside it.