What do you do if your TV loses power on a hill?

[bobinyelm]

Last week my wife and I were traveling Utah Rt 24 across the state, and were climbing a very steep 10% hill w/ our 8000# 5th wheel in tow, and my usually adequate Dodge 3500 dually quad cab Cummins w/ 6spd manual (300hp and 500ft pounds torque) just didn't "feel" right. It was butter smooth as always, but lacked power, and rather than cresting the hill easily in 3rd or 4th at 2000rpm, I had been forced to shift down through the gears into 1st and could only make forward progress at near redline of 2900rpm at 12mph or so.

I knew I was in trouble, because if I fell out of the torque curve, I had no more gears to shift down into, and the only solution was to stop and lock up the brakes.

We were at 6500ft at 102degF part way up a VERY steep hill (10% is one Hell of a grade!) w/ a 1000ft cliff rising above us on one side of the narrow 2 lane road, and a 1000ft cliff DOWN on the other side with no guard rail. Backing up was not a solution on the 2 mile uphill, and we had no cell reception to call for help.

That made me think about what one should do in such a situation, which I had NOT done previously. As a now-retired Captain for a major airline with 35 years and 26,000 hours of Air Force and airline flight time, I prided myself on having "back-up" plans, but here I was with NONE in mind.

I've given it a lot of thought, and if this happens in the future, this is what I will do. Like with flying, having a plan in mind beforehand is often the difference between survival, and the alternative.

1) Apply brakes.
2) Have wife insert chocks on downhill sides of all 4 trailer tires.
3) Consider pulling emergency break-away pin on trailer brakes (if it's REALLY steep).
4) Have wife drop landing gear to take weight off 5th wheel hitch.
5) Have wife pull hitch handle to disconnect 5th wheel from truck.
6) Drive truck forward 4ft, pick up wife, and go for assistance (assuming no Cell Service at scene). If driving away is not possible, set TV emergency brakes (or use trailer blocking behind wheels to keep it in place).

Hopefully neither I, nor any of you, will get into that situation, but if I do, at least I can calmly execute a plan that should assure safety for the TV occupants.

If some of you have better ideas, please chime in!

Bob
BTW, We followed lower altitude, not mountainous roads home to Texas, and have not yet discovered why the truck was low on power that afternoon when only the day before we'd been EASILY topping 6% grades at 10,000ft elevation in 4th gear at only 2000rpm and about 1/4th throttle. My truck was running smoothly, has no MIL codes (Check Engine Light), and never missed a beat other than feeling gutless on that hill.

[RustyJC]

My knee-jerk reaction is fuel starvation due to possibly getting a bad load of fuel. I'd start by changing the fuel filter and checking closely for sediment and/or water plugging the removed filter. Something DEFINITELY isn't right.

Rusty

[TXiceman]

With the trailer stopped, pulling the break away pin on the trailer will do no good and it will run down the battery pretty fast.

Ken

[Skip426]

Lost a reply in cyber space; hope this isn't a duplicate .
If the engine pulled 2900 rpm and still had no power, I don't think it's a fuel supply issue; although that's the first thing to check; second air filter, third lift pump pressure.
Possible turbo waste gate sticking ; even a slightly open wastegate will drop your power.
No mention of your trucks year, so I don't know if you have a common rail ,or VF-44 fuel system. Although both were involved in a change up to re-locate the lift pump back into the fuel tank, when the pump failed.
Do you have a boost gauge ? If you don't find the cause of this issue , you might want to install one before your next trip.
Hope you find out what caused this as that kind of lack of power, would weigh heavily on your mind while driving.
NOTE: some faults in the VF-44 pump would not put the MIL light on; because they were not emissions related. you have to scan the ECM for codes.

[RustyJC]

Originally Posted by Skip426

If the engine pulled 2900 rpm and still had no power, I don't think it's a fuel supply issue.....

That's 2900 RPM in 1st gear while producing (by the OP's description) little or no torque. With the gear reduction in play, that's not much different than revving the engine to 2900 in neutral, which takes very little fuel flow while producing almost no BHP/torque. Fuel starvation = lack of BTUs available to burn = lack of torque/BHP, irrespective of RPM.

There are, as you mention, a number of potential reasons for fuel starvation, but (especially if the OP had refueled between his reported good versus poor performance) changing fuel filters is the first place to generally start unless some obvious symptom indicates otherwise.

Rusty

[bobinyelm]

BTW, it's an '03 CRD 300hp/500ftlb engine.

When home, I changed both fuel filters (I run an Air Dog lift pump/filter unit that pumps enough fuel to fill a swimming pool), and also changed my TPS (throttle position sensor) and FCA (fuel control actuator) as a precaution.

The engine ran GREAT-just no power. It COULD have been a sticking waste gate, and I AM going to install a boost pressure gauge and EGT. To be hones, it FELT like there was no boost (but it could have been low injection fuel pressure), but it had much more power at 2900rpm than 2000rpm I can tell you!

When at lower altitudes, the truck FELT fine and had plenty of power again (maybe not 100%-can't say for sure), but it felt OK, and upon reaching 7000 the next time it did fine w/ 6% grades. So the condition was either temporary, or the truck (rated to tow 14,000#) can't handle 8000 at 10% grades.

Given I had 2 fully charged 100ah batteries aboard, I'd like to think the e-brakes would have stayed engaged a while. Plus, if I'd uncoupled, but left the 7-Pin connected to my truck, the brakes would have stayed powered as long as my truck engine was running (though it would have trashed my brake controller). That way, if the trailer had rolled down hill, it wouldn't have taken US in the truck with it.

In any case, pulling the pin would have given us time to unhook and let the SOB roll off the cliff alone. I'd have hated to have lost the (insured) 5er, but riding it down would have been unacceptable. Given there was no traffic (didn't see a soul for about 45m, and maybe 3 vehicles total on the entire route).

Route: http://screencast.com/t/JY1kCqqNKknO

[RustyJC]

IF you were low on boost for whatever reason, the ECU is going to cut fueling to match fuel to the air mass flow available in order to (1.) protect the engine by holding down EGTs and (2.) holding down particulate emissions to prevent turning day into night with black soot. The result is that low airflow can result in low fueling and low power.

Obviously, it would help tremendously to have some idea of boost level, EGTs, fuel rail pressure, etc. when this happened. Without enough data, it's hard to make an accurate diagnosis via the Internet.

Rusty

[bobinyelm]

Originally Posted by RustyJC

IF you were low on boost for whatever reason, the ECU is going to cut fueling to match fuel to the air mass flow available in order to (1.) protect the engine by holding down EGTs and (2.) holding down particulate emissions to prevent turning day into night with black soot. The result is that low airflow can result in low fueling and low power.

Obviously, it would help tremendously to have some idea of boost level, EGTs, fuel rail pressure, etc. when this happened. Without enough data, it's hard to make an accurate diagnosis via the Internet.

Rusty

Yeah, everything is inter-related.

Yes, it WOULD be helpful to have recorded "live data" during the incident.

I suspect it was a "one-time" anomaly, or I would have noticed that something was wrong earlier as there were MANY hills of not along the way, and I didn't sense anything too out of the norm until I couldn't hold the gears I expected I would looking ahead at the grade.

As you know, after thousands of miles, at least in daylight (when you can more easily judge grades), you get a really good idea how the hill is going to "feel," how much throttle you're going to need, and what gear you think you'll end up in cresting the hill.

This one caught me by total surprise, and I was incredulous as I lost gear after gear and found myself jamming it in first (rather than matching rpm at about 2000rpm) trying not to lose any speed as I KNEW I'd need every rpm I could hold onto even in bottom gear. I NEVER turn 2900rpm-this was the first time ever, and I needed every revolution as it turned out.

An experienced driver in a familiar vehicle over repetitive hills isn't usually surprised to the level I was, so I am guessing more as time passes, something "stuck" or didn't open as commanded when the parameters called for power.

I won't feel totally comfortable until I find the cause, which at least now at Sea Level isn't shouting out to us.

I think form now on, I'll think about that on every really steep grade on a marginal road (narrow/mountain/no shoulders) I approach from now on.

[clyon51]

Wow, scary situation! Can't add anything regarding the engine.Sounds like you have a workable future plan. Have you considered a few JATOs on the back of that 5er?

[bobinyelm]

Originally Posted by clyon51

Wow, scary situation! Can't add anything regarding the engine.Sounds like you have a workable future plan. Have you considered a few JATOs on the back of that 5er?

No, but maybe a explosive de-coupler on the 5th wheel hitch would be nice.

Just push the button, and your problems are gone (or just starting if someone's behind you).