'pants

I've had all manner of fuel-pressure/filter-clog/intake-screen issues in the past, but this isn't one of them. Early this evening, I was cruising along on the freeway on my way home on what would have been a ~30-mile jaunt, when I felt that queasy loss-of-power feeling. I worked my way over to the right in neutral as quickly as I could, and by the time I'd coasted as far off as I could onto a shoulder, the engine had quit entirely and wouldn't restart.

I was "certain" it was a recent new fuel problem: I have an electric in-tank pump, and the output line slipped off the pump a block from home, just the last time I drove it - which I've still not fixed 'permanently' - so it blew my mind to find that, well, no, that was NOT it... I had about 20psi on my mechanical gauge (connected to the IP inlet) this time...so no question there's adequate fuel supply and pressure. (It also gushed out of the QR fitting on the fuel canister when I turned the ignition on.)

Also checked the diesel stop solenoid - fully locked (up) and loaded when the key is cranked over.

It cranks like crazy, but there's not even a hint of ignition.

So yeah, I hadda get towed home tonight. Tomorrow, not knowing what else to do, I'll crack some injectors and crank it to make sure there's some fuel spitting out. Of course I'll check back here first to see what else might be a good diagnostic check.

What else should I be looking at/trying?

The only potentially-relevant recent issue is that, on rare occasions, I'll hear/feel the idle drop, then it'll die, but it's never given me a problem restarting like this.

Thanks - Dave

gorms

I would start by removing the shut down solenoid to make sure the clamped connection to the shaft sticking out of the pump is tight, and the little woodruff key is in place. The solenoid may be working properly but if the arm connected to that shaft isn't tight it may not be turning enough.

Curious as to why you run an in tank pump? 20psi is about what you want just off idle, more like 30 under load.

How many miles are on the truck/injector pump? Something may have gone wrong within the injector pump, tough as they are. Any other info like modifications, mileage etc may help.

'pants

thanks, Gorms - it turned out to be the overflow valve...or maybe the fuel module...or both? The spring was in 4-5 pieces when I pulled it out, and it took several removal/replacement sessions (after each it would start, but only after a LOT of cranking, and then die after a minute or two of unsteady idle). I noticed the tone of the "flow" buzz/rush sound in the circuit (the electric pump on, the engine off) was unsteady, and that got me to find that a second problem was happening in the fuel module: the return-hose was haphazardly spilling out into the main tank, vs the screened central area (which leaves the pump starved for fuel), so perhaps as the tank volume dropped, that starvation (and air injection) was getting worse. Since I was indeed seeing pressure-readings on the mech gauge of around 20psi, the bad OFV spring might not have mattered, since it seems like the electric pump was still keeping enough pressure on the supply side...but then again, that pressure may have included some great big slugs of air.

I installed the in-tank pump about a decade ago as a diagnostic & Cummins newb, not realizing that the real problem at the time was that my in-tank intake screen had plugged with some biodiesel-related goo ("chicken skin.") I installed it anyway, because it was to be part of a conversion to WVO (which would have allowed me to easily switch between WVO and purge fuel, eg diesel). And then I didn't follow through with those plans due to ever-expanding entropy. I still like the idea of not having to crank my engine any more than necessary to recover after an air-in-IP event, which seem to happen all too often, particularly with my scary-steep driveway and the tendency of the module to let the pump run dry when the tank gets to 1/4 or less.

I've got about 30psi, steady now, with my junk-box replacement spring, and I'm soliciting recommendations for a replacement OFV...adjustable? I dunno.

As a side note, having just seen the inside of the OFV, I can't help but think that fuel-contamination (with water, specifically) has shortened my IP's life; the internals have the same 'stained' dark-brown look that I recall seeing in an IP from an excavator that I ended up having to shell out almost $2K to have rebuilt. The shop that rebuilt it seemed to be indicating that they seldom see pump interiors that look that nasty - and there it was in my Dodge's OFV, which I also used to run on biodiesel...