Engine dies when hot, slow moving, uphill, at elevation (KrZy8)

dcarver · Jun 8, 2017

Last weekend at YFO Yosemite run KrZy8 started running rough then the engine died.

Conditions:

Hot, temp indicator at 108F, both fans running
Slow speed. 1st gear, stop and go, uphill, clutch n' go, stop, clutch n' go. Repeat many times as cage drivers paid entrance fee at Yosemite kiosk.
Noticed voltmeter swinging 14.3 to ~12 vdc
At some elevation, maybe 3,000 to 4,000 feet?
~235k on OEM fuel pump, 2006 model year

I popped the gas cap, thinking maybe it was lack of venting and possible vacuum in the tank, then went and sat down in the shade as it was hot outside and I was feeling cranky. And the forest range was being a **** about me having the bike 'parked' in the middle of the road in front of the kiosk.

Did NOT hear any whoosh of air into tank when cap was lifted.

Several minutes later went back, turned key on and KrZy8 fired up into a gentle and normal purr.

So I rode it back to the hotel. Ran great. About one hour of run time no issues. All good. So then:

Stopped at O'Reilly for a can of BrakeKleen.
At hotel, ensured both overflow tubes were clear by spraying BrakeKleen into each.
Also sprayed the fuel cap vent path by using the little red BrakeKleen straw - placed it on the little hole under the cap and saw BrakeKleen coming out around the upper side of the caps internals. Sprayed into V1 and liquid exited V2. Thanks for the pic FredW.
Note - I did not check the vent from the tank.

Later, went on afternoon ride with Panman and crew. Ran great until a similar condition as described above.. Slow going, 1st gear, up hill, hot, both fans running. It was about to die again when Panman stopped so we could cuss him out for taking us on a goat trail too tough for goats.

Popped the cap again, let it sit a bit, then rode it back to hotel. But I really thought I was going to be towed in. And the Harley guy named Jeff was grinning ear-to-ear as it was metric bike having troubles..

Long of short, rode it home 230 miles no problems.

Here's my thoughts -

It's a fuel tank venting issue
- Check fuel tank vent line venting - here's pix stolen from FredW
It's a failing fuel pump issue
Take tank off Naomi (2013 FJR) and try to replicate conditions (hot, uphill, slow going)

Any other ideas, Peeps?

Thanks in Advance,

dCarver & KrZy8

RavFJR · Jun 8, 2017

I think you're on the right track... Possible vapor lock due to weak fuel pump. I've had this problem on another bike before. It would let me know when it got above 105F...with a little rest on the side of the road. Good luck.

Viper Pilot · Jun 8, 2017

I don't see how a tank vent issue would impact the charging voltage as you indicated?

Fred W · Jun 8, 2017

TPS going south? That seems to happen when heaviliy heat soaked.

Did it always clear immediately when you popped the cap? Or only after a cool down?

Bill Lumberg · Jun 8, 2017

I had a similar problem on my last bike when my evap canister pumped charcoal pudding into my fuel filter. Not a cali model is it?

Constant Mesh · Jun 8, 2017

Don't know what happens when you're running the fans constantly with the engine idling for long periods of time?

May be using more watts then the charging system can put out at idle.

Too bad you can't switch off the headlights under those conditions.

When the ambient temp is above a 100 degF and the air is thinner at altitude, the fans probably don't cool as efficiently and have to run a lot more.

Did it crank well indicating a strong battery after cool down?

Mr_Canoehead · Jun 8, 2017

Was the fuel boiling in the tank?

Viper Pilot · Jun 8, 2017

Good point on the fans running alot. That could account for the low charging voltage.

dcarver · Jun 8, 2017

Viper Pilot said:
I don't see how a tank vent issue would impact the charging voltage as you indicated?

I agree. I added the volt observation as I have a DL650 that had low charging voltage. The dealer replaced the stator and RR, no real improvements. The real problem was a failing fuel pump that was placing excessive load on the charging system. The wiring on the pump was intermittently shorting, then clearing, shorting, clearing. I saw similar voltage oscillations then as I do now. So of course my brain says it just *has* to be that issue again.. although I know better than to jump to conclusions without using systematic troubleshooting techniques.

Fred W said:
TPS going south? That seems to happen when heaviliy heat soaked.
Did it always clear immediately when you popped the cap? Or only after a cool down?

Fred, another possibility.. TPS. Didn't think of that. In both occurrences, I did not immediately attempt a restart. However, in both instances the cooling would have been slight. At Yosemite the offtime was ~5 minutes. Old Highway was more like 20 minutes.

Bill Lumberg said:
I had a similar problem on my last bike when my evap canister pumped charcoal pudding into my fuel filter. Not a cali model is it?

It is a denuded Cali model. No charcoal canisters.. Excess fuel goes straight to pavement.

Constant Mesh said:
Don't know what happens when you're running the fans constantly with the engine idling for long periods of time?
May be using more watts then the charging system can put out at idle.

Too bad you can't switch off the headlights under those conditions.

When the ambient temp is above a 100 degF and the air is thinner at altitude, the fans probably don't cool as efficiently and have to run a lot more.

Did it crank well indicating a strong battery after cool down?

Previous experience watching the volt meter when fans kick on is a step-change high to lower but stable at the lower reading e.g. 14.2 to ~13.7 with a +/- .1 swing. This swing is much greater ~12 to ~14.2 vdc.

It cranked strong on restart. KrZy8 has a 2 month old battery and fresh stator + RR. I see 14.3, 14.4 regularly now where as before max as ~13.5 unloaded.

Regarding headlights... EasternBeaver makes kits to kill one light. I have that setup on a DL650 and it works great. I might consider doing the same for the 2013 FJR I'm farkling.

Mr_Canoehead said:
Was the fuel boiling in the tank?

Not that I could tell. I've never boiled before and I've been in much hotter weather. Tank bottom insulation is good and installed.

RossKean · Jun 8, 2017

12 volts is TOO low. You are not getting sufficient recovery from your charging system to cover the draw. Can't say if it is a function of your charging system, weak battery or simply because rpm is too low to produce the necessary amps.

Swap Naomi's battery in and see if anything changes.

dcarver · Jun 8, 2017

RossKean said:
12 volts is TOO low. You are not getting sufficient recovery from your charging system to cover the draw. Can't say if it is a function of your charging system, weak battery or simply because rpm is too low to produce the necessary amps. Swap Naomi's battery in and see if anything changes.

Except when this condition kicks in, even with fans, headlights on hi beam, 2 Clearwater lights on, I have 13.5 - 13.7 vdc. It's a new battery, stator and RR. My thought is something is failing, drawing excessive current and pulling the voltage low.

Fred W · Jun 8, 2017

I agree. Cart before the horse. Chicken before the egg. 12V will not cause the fuel injection to act up. It has to be lower than that. But it, being coincidental, is (probably) an indicator of WTF is going wrong. Which would suggest that my prior suggestion of TPS going TU would not be the right answer, since that will not affect charging voltage.

Being in the business of troubleshooting highly complex electric/electronic equipment, I can tell you that the most difficult problems to find are the intermittent ones. So, go out and break that ***** and then it will be easy to find! You can thank me later.

exskibum · Jun 8, 2017

Contact Sam (puppychow). At YFO, he was telling me about some bizarre '05 engine dying issue he dealt with for an extended time, but I don't remember the specifics of the circumstances under which it would die. It bedeviled him for a while, thinking it was tank venting, fuel pump, maybe even TPS, etc., and trying numerous things to fix it. Finally, he discovered that it was some other part, had to do with causing a vacuum leak, IIRC.

Not sure you have the same problem, but there are some suspiciously similar aspects to it.

Constant Mesh · Jun 8, 2017

Does the idle rpm drop very much at 3500 ft elevation?

Less oxygen for combustion so less fuel injected for the fixed idle throttle opening.

Prior to the throttle by wire FJRs I assume idle rpm would be affected by elevation changes.

One might believe if you had a shorting fuel pump motor you'd be melting the fuel system fuse.

Fuel would not be boiling inside the pressurized fuel delivery system even though it might be in the tank around the fuel pump.

RossKean · Jun 8, 2017

dcarver said:
RossKean said:

12 volts is TOO low. You are not getting sufficient recovery from your charging system to cover the draw. Can't say if it is a function of your charging system, weak battery or simply because rpm is too low to produce the necessary amps. Swap Naomi's battery in and see if anything changes.

Click to expand...

Except when this condition kicks in, even with fans, headlights on hi beam, 2 Clearwater lights on, I have 13.5 - 13.7 vdc. It's a new battery, stator and RR. My thought is something is failing, drawing excessive current and pulling the voltage low.

You could have 13.5V up to the point the reserve capacity of the battery is gone. The AGM battery is capable of putting out lots of amps while maintaining fair voltage UNTIL it is approaching empty. I think you need to ride under the problem conditions with an ammeter on your system. See if there is net discharging. If so, you might manage 13+ volts until the battery runs down. Stopping for a little while (or a short higher rpm run) would likely allow the battery to "recover" enough to start it up again. I agree with Fred that 12 V will still run the FI system (and ECU and fuel pump) adequately but maybe it's dipping lower than that??

I have to think that the performance issues are related to the voltage stuff - either the system just doesn't charge things sufficiently or there is some sort of big electrical load (short?) that shouldn't be there. Again, the ammeter while running would be a big help.

08FJR4ME · Jun 8, 2017

If it was a voltage issue the bike would not restart. I put my GUESS on fuel issues. Not enough getting to the engine and somehow being restricted. Extreme heat influencing the problems since the fans want to run not stop.

JMO,

Dave

dcarver · Jun 8, 2017

Fred W said:
So, go out and break that ***** and then it will be easy to find! You can thank me later.

Trust me Fred, I can break ****. Just ask anyone. I have high ambient temps where I live. And hills. And a AAA card!

exskibum said:
Contact Sam (puppychow). At YFO, he was telling me about some bizarre '05 engine dying issue he dealt with for an extended time, but I don't remember the specifics of the circumstances under which it would die. It bedeviled him for a while, thinking it was tank venting, fuel pump, maybe even TPS, etc., and trying numerous things to fix it. Finally, he discovered that it was some other part, had to do with causing a vacuum leak, IIRC.
Not sure you have the same problem, but there are some suspiciously similar aspects to it.

I'll PM him, Thanks Rich.

Constant Mesh said:
Does the idle rpm drop very much at 3500 ft elevation?
Less oxygen for combustion so less fuel injected for the fixed idle throttle opening.

Prior to the throttle by wire FJRs I assume idle rpm would be affected by elevation changes.

One might believe if you had a shorting fuel pump motor you'd be melting the fuel system fuse.

Fuel would not be boiling inside the pressurized fuel delivery system even though it might be in the tank around the fuel pump.

Idle is fine, no noticeable drop. The first time, it felt like the high altitude sickness ECU that came on early FJR's. Still running but not much power. No big crankshaft slaps like ignition failures tend to present. Regarding fuel pump, I tested both the 2013 and 2006 when things were 'normal'. The average draw is 3 to 3.3 amps, steady as a rock. When the DL650 was having fuel pump issues, it easily brought max charging voltage down from 14.3 to ~13.1 steady state. BTW, the Suzuki charging system is much cleaner and with more reserve than the FJR. Clean as read on a scope.

RossKean said:
You could have 13.5V up to the point the reserve capacity of the battery is gone. The AGM battery is capable of putting out lots of amps while maintaining fair voltage UNTIL it is approaching empty. I think you need to ride under the problem conditions with an ammeter on your system. See if there is net discharging. If so, you might manage 13+ volts until the battery runs down. Stopping for a little while (or a short higher rpm run) would likely allow the battery to "recover" enough to start it up again. I agree with Fred that 12 V will still run the FI system (and ECU and fuel pump) adequately but maybe it's dipping lower than that??

I have to think that the performance issues are related to the voltage stuff - either the system just doesn't charge things sufficiently or there is some sort of big electrical load (short?) that shouldn't be there. Again, the ammeter while running would be a big help.

Well, since I happen to run a Metrology Lab, I'm pretty sure I can source a nice small ammeter to do that test. Maybe I'll have the first dash mounted ammeter which will become the envy of the FJR community.

08FJR4ME said:
If it was a voltage issue the bike would not restart. I put my GUESS on fuel issues. Not enough getting to the engine and somehow being restricted. Extreme heat influencing the problems since the fans want to run not stop.
JMO,

Dave

Yeah, I tend to agree. Unfortunately, I'm still working way too much OT and can't spend the time.

I think I'll try the easy stuff first -

Check diagnostic codes (TPS?) If not fixed (INF)
Swap gas tanks, test. INF -
Put ammeter on charging circuit ride to failure INF -
'Let it Develop' - Fred's version of ride the ***** till she breaks!

Thanks for all the advice guys!

Don

RossKean · Jun 8, 2017

SOMETHING caused the system voltage to drop. Insufficient stator output at RPM, bad stator, bad R/R, bad battery, bad connection, some unknown fugitive load...

Did you check voltage with the ignition off (no excess loads)? It might be 12 V only when (over)loaded with fans etc. and insufficient RPM and come back to 13+ when loads are removed - enough to restart. Does the voltage (and bike behavior) improve if you pull the clutch and keep rpm in the 3000 range?

I still think you need to look at whether the battery is in a net charging or discharging scenario (using ammeter) when you are experiencing this behavior (as well as the voltage). I think the root problem has to do with power. 12 V will operate the injectors and computer but just because there is 12 V at the battery, it doesn't mean there is sufficient at all parts of the wiring harness (ECU, coils, injectors).

I HATE electrical issues - especially intermittent ones. Much easier to fix if you find a dead short (or broken wire) somewhere. Good Luck.

exskibum · Jun 8, 2017

dcarver said:
Idle is fine, no noticeable drop. ]The first time, it felt like the high altitude sickness ECU that came on early FJR's. Still running but not much power. No big crankshaft slaps like ignition failures tend to present. Regarding fuel pump, I tested both the 2013 and 2006 when things were 'normal'. The average draw is 3 to 3.3 amps, steady as a rock. When the DL650 was having fuel pump issues, it easily brought max charging voltage down from 14.3 to ~13.1 steady state. BTW, the Suzuki charging system is much cleaner and with more reserve than the FJR. Clean as read on a scope.

Sam said something just like that about altitude sickness -- I recall because altitude sickness was a new problem when the 2006 Gen.II arrived, and we both have 2005 Gen.I bikes. I commented on that and, of course, Sam knew the same thing. Thinking your first course of action might be consulting with him. Besides, both your bikes have been California deer victims, . . . not that it's a deer related sickness at issue here.

Engine dies when hot, slow moving, uphill, at elevation (KrZy8)

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