I recently returned from a trip towing my 8000 pound 5th wheel w/ my stock '03 HO Dually w/ 6spd manual transmission.

My real question follows the narrative just below.

One day I was climbing 6% slopes at 10,000ft elevation (80degF) in 4th gear no sweat and 1/4th throttle, and the next day (on a steep portion of UT 12 between Bryce Canyon and Capitol Reef NP) the ONLY gear I could hold was 1st gear almost floored at 2900rpm at 6500ft elevation and 100deg F. The signs indicated the grades were 8% and maybe a tad more.

There had been PLENTY of times on the trip I'd been well over 100degF (as high as 116deg F) at over 6000ft on steep grades and NO problem.

As soon as I changed my undies (the consequences of NOT topping that grade on a narrow 2-lane road w/ a 1000ft rise on one side, and a 1000ft drop on the other were not pleasant since there was no place to pull over, or back down the mile long hill), I pulled over and looked for loose turbo hose clamps or a burst hose/intercooler. Everything looked FINE.

We continued the trip, and for the most part everything felt fine, especially as we reached lower and less steep.

Now at home, we hooked a SnapOn scanner up and couldn't find anything obvious. The Control pressure in 5/6th at lower rpm (1600-2000) at WOT is only 18.5kpsi (it hits 21.5kpsi WOT in the lower gears at 2200-3000rpm). I have no gauges YET (which is part of my question farther down), so I can't say what the parameters were on that grade, but the truck felt like I'd swapped the Cummins for a Corolla engine, and I didn't like it one bit. It was making NONE of the torque I am used to feeling at 2000rpm, hence having to wind it out to 2900rpm to get up the hill in 1st at about 12mph or so (it wouldn't even hold 2nd at 2900rpm) . The engine was butter smooth always, idles like a Honda Civic and has always had plenty of grunt for me. Just on this ONE hill ONCE it let me down badly, and I need to find out why, then fix it.

As a matter-of-course returning home I replaced my AirDog lift-pump fuel filters, the TPS (since everyone said that at 130k mi it was close to needing replacement anyway), and the FCA (since the 18.5kpsi WOT at 2000rpm seemed low). The engine runs and feels the same after the replacements, which is not bad, since it feels fine at sea level (no hills anywhere close to here where I live in Texas). Hell, it felt fine an hour after the incident (though we didn't have another hill that steep).

Note that under ALL conditions the actual rail pressure (on the scanner) perfectly matched the ECU's Command Pressure, so I doubt I have a CP3 problem if I understand the system right.

I am about to buy some monitoring equipment (so I won't be so ignorant of the parameters after the next such possible incident), and I have several choices:

1) Mechanical Boost and EGT (Westach at $300) in a pillar pod.
2) Edge electronic monitor that sees a bunch of parameters
3) Bully Dog Gauge/Monitor Package for $300 (see http://www.bullydog.com/product.php?ID=1 )
4) Bully Dog Gauge/Monitor/Tuner all-in-one for $500http://www.bullydog.com/product.php?ID=2

My understanding is that Bully Dog is inferior to Smarty Jr for the Cummins, but I am not THAT interested trying to make BIG HP gains, though perhaps 30-50hp more might be good for towing, and for only $200 more than for gauges alone, you get a tuner/programmer w/ Bully Dog (vs 500 extra for a Smarty Jr) that says it has a 50hp Tow Package that won't melt pistons.

As I said, MOSTLY I want to be able to monitor things (EGT, Boost, Command and Rail Pressure, TPS %), and extra power is a distant second since towing "only" 8000-10,000 pounds the stock 300hp/500ftlbs should be sufficient w/ the 6speed I would think.

Sorry for the long, possibly confusing, post, but...

Opinions or suggestions?

Thanks-
Bob

 

Are you using a draw straw or the stock fuel pickup? I have seen the stock fuel screen in tank become plugged and restricts fuel flow at WOT.

 

Stock fuel pickup through the Air Dog to the engine.

If it were still down on power or performance I'd be more likely to suspect that, though I suppose that it's possible a "blob" in the tank blocked the screen for just those two minutes or so on the hill.

I normally don't demand that much of the available power (even on 6% grades-maybe 1/4th throttle at most), and wouldn't have expected to need anything CLOSE to full throttle on that one.

The ONLY time I ever even did a WOT was after the return home from the vacation, and was doing some diagnostic experiments. (On that hill I was down to 1st at 2900rpm, but did have SOME reserve power in that gear. I was probably at 3/4 throttle, and didn;t want to approach 3100 rpm redline so modulated the throttle to stay just below 3000rpm.).

I never had to use more than 2200-2300 rpm with 1/4 throttle on ANY hill before, and that was probably 3rd or 4th gear at up to 10,000ft and 6%+ hills the day before.

 

Adding gauges are excellent for preventing engine damage but also valuable for diagnostic purposes when you have a situation like this.

Information from a boost gauge, low & high side fuel pressure gauges, EGT gauge, accurate water temp gauge would have likely told you exactly what was happening.

 

I agree 100% and why I am trying to get opinions on the best gauge package for the money.

For the $300 of the BullyDog gauge module, I could only get the Westach Boost/EGT gauge, which is a great gauge, but doesn't monitor as many parameters as the electronic one.

I like the BullyDog gauge module, but am wondering whether I should spring for $200 more for the same gauge package w/ built-in programmer.

 

For only a couple hundred bucks extra, I'd go for the extra power too!
Of course I bought a diesel because it'll move out! Empty or loaded, but in stock form, still kind of anemic.
I've seen the APPS (TPS) go out on an 03 and pretty sure that wasn't your problem. That issue results in a dead pedal, you wouldn't have gone anywhere. Otherwise, I have no clue what happened, but it sounds like a fuel suppl problem or a glitch in the ECM.

 

Yes. I am leaning toward an ECM problem (though they generally don't fix themselves, but then fuel problems don't either), or maybe a stuck waste gate (but I don't see it would have been open so as to stick in the first place, since I started with very little throttle and advanced it smoothly, probably not exceeding 20psi until I realized what was happening and used as much throttle as necessary to get over the hill in 1st gear).

In all honesty, it FELT like I had no boost, but probably not enough fuel would felt similar since they are tied together (which came first, the chicken or the egg situation). There was none of the "growl" I am used to hearing with more throttle (I have no muffler and am straight-through). It takes FUEL as well as BOOST to make growl, after all.

I think I need the most comprehensive gauge package (boost/rail pressure/EGT minimum) to see what's happening the NEXT time this happens, which it probably will since we have not been able to diagnose what made it happen LAST time.

The Edge CTS gauge package (or the BD Watchdog) will cost LESS than throwing more expensive parts at the problem to see if any fix it, especially since it doesn't feel "broken" right now! Can't fix what ain't broke. I guess you CAN, but how do you KNOW you fixed it that way?

As far as Bully Dog, almost everyone has worked to convince me that the Bully Dog tuner can, and has destroyed ECMs, while Smarty Jr has not, so spending the extra $300 over the BD to get the Smarty is money saved. I imagine the number of ECMs destroyed are few, but with MY luck...

BTW, some had guessed that the engine went into "limp home" mode, even though it didn't throw a MIL code. WHAT things will cause the engine to go into a "limp home" condition? I ask because the engine appeared to be at normal coolant temp (it would go from 195 indicated to about 205-210 on each uphill section) and I sure wasn't working it harder than an hour or a day earlier on similar roads (though maybe 1-2% less grade).

Thanks,
Bob

 

I am guessing that it was not smoking like a train when you were on the hill because you would have said something about it. That kinda rules out a air flow issue, but with no codes a once in a while fuel system problem could be hard to solve. If it was me, I would forget about it unless it happens again. Not to insult you but are sure the clutch was not slipping? I am sure that you would have smelled it when you stopped.

 

On second thought the clutch would have burst into flames if it were slipping on that long of a hill.