R1100RT engine spluttering

[simonjrwinter]

On my way into London today, my engine started to splutter very badly. It stopped completely on a couple of occasions, and I just managed to ride the last mile or so on one cylinder with the second cutting in now and again. After work I expected to have problems starting running the thing, but it started and rode home pretty much fine (the odd tiny splutter/flat spot occasionally, but nothing that worried me too much)

I'm worried it's going to do it again and let me down again, so any ideas what it could be? what I should check?

I'm guessing it may be some dirt in one of the fuel lines or injectors? maybe plugs? What should I check?

Any advice much appreciated.

 

Simon

 

('99 R1100RT)

[Woodie]

WAG (Wild A**ed Guess)

 

HES (Hall Effect Sensor)

 

Search for that, double-check your symptoms.

[Joe Frickin' Friday]

Intermittent failures suck. It gets hard to pin it down if the problem isn't there when you go looking. But we can point to a few possibilities.

 

Like Woodie says, the HES is a prime candidate, especially if it was raining at the time.

 

Remaining candidates would be spark plugs/wires on the bad cylinder (though one would expect trouble initially at high loads), and a plugged fuel injector.

 

Easy/cheap to replace the plugs. If that doesn't work...

 

swap the fuel injectors, left-for-right. If the problem follows the injector to the other cylinder, then you need a new injector. If not...

 

you've probably got a bad HES, which is a known weak point on the 1100's. Once the sputtering sets in permanently you should easily be able to diagnose this.

 

You can replace with a new one, which reportedly has high-temp insulation on the wires and will likely last the life of the bike, but is not cheap. The alternative, if you're handy with a soldering iron and have a spare bike to ride for a while, is to rebuild the old one.

[Brian PDQ Signs]

I was thinking the Hall sensor too. My bike bucked like a bronco, hiccuped, etc about 60 miles from where I got it. Couldn't keep it running. When the bike cooled down it would run from a mile to a couple of miles before it would die again. I don't know if they replaced the Hall Sensor but it has been fine ever since.

 

Other things could be fuel filter, water/moisture in around coils.

 

Best of luck,

[T__]

On my way into London today, my engine started to splutter very badly. It stopped completely on a couple of occasions, and I just managed to ride the last mile or so on one cylinder with the second cutting in now and again. After work I expected to have problems starting running the thing, but it started and rode home pretty much fine (the odd tiny splutter/flat spot occasionally, but nothing that worried me too much)

I'm worried it's going to do it again and let me down again, so any ideas what it could be? what I should check?

I'm guessing it may be some dirt in one of the fuel lines or injectors? maybe plugs? What should I check?

Any advice much appreciated.

 

Simon

 

('99 R1100RT)

 

Simon, as mentioned above possible electrical gremlins-- as in Hall Sensor wiring, etc.. Possible bad gasoline (had you just filled the tank?),, possible fuel line problem in the fuel tank,, possible fouled spark plug, plug wire etc.. . Well you get the picture, it will take a full check of all the systems to find your problem--That’s assuming it acts up enough to find it..

 

Here is an additional thing to check—IF, you have a fuel controller like the Techlusion or similar be sure to turn that off & even better yet disconnect it from the injector pick up.. I have found a couple of the early Techlusion units that got moisture in their little black box & that will make the engine run just like yours is.. It can also be very intermittent.. So if you have a fuel controller start there first as it is quick & easy..

 

Twisty

[Jim Moore]

That sounds to me like a fuel filter problem, but the Hall sensor is not a bad gues either. A Hall sensor problem normally leaves you sitting on the side of the road.

[simonjrwinter]

I've pulled the plugs (They were fine) checked all the cables and run some injector cleaner through the bike on a 20 mile ride this morning.

It seemed to behave ok, but there's still a miss now and again, and when nearing home I got a VERY SMALL amount of hesitation/missing. I'm guessing from the advice I've been given and the other posts I've read that the Hall effect sensor(s) are on their way out.

I've had a look at the instructions for changing them, but is there anybody in the UK who does this (not the whole thing, just changing the sensors on the plate)

Again, any advice much appreciated and thanks for all the posts so far.

Simon

[AndyS]

You could try using a hose and dousing the area from the alternator belt cover up around the right hand side of the bike(the basic route of the HES cable routing) and see if the moisture brings the problem back.

Better to do this at home and it fail than in the middle of picadilly circus and stop the traffic!

Andy.

[Boffin]

The problem is usually the wiring rather than the sensors. The wires overheat and crack under the clamp onto the front of the engine. Replacing the wiring harness is a relatively easy task, though should I ever need it, I would take it to North Leicester Motorcycles who are an old-fashioned bike shop that can repair things, not just replace them. I am fortunate that they are just three miles from my home.

 

Andy

[simonjrwinter]

Right,

 

just ridden the bike again. I want to be as sure as I can it's the hall effect sensors, so any advice please.

 

Water. Doesn't make any difference. SOAKED the front/sides of the engine with it running, no difference.

 

Heat. It DOES seem to get worse the hotter the bike gets

 

Fuel. Put fresh fuel in...no difference

 

injectors. Put some cleaner through the system, no difference. (although this doesn't mean the injectors are ok I suppose)

 

Riding the bike tonight, it runs ok at part throttle (say 3000 rpm in 4th gear) but open it up and it starts to accelerate, but after a couple of seconds starts to "gag" as if it's being starved of fuel.

I took the tank off today and looked at the fuel filter inside. It was stamped "2007" so it looks to have been replaced fairly recently. I didn't have a replacement so couln't change it,

It seems to me more like a fuel problem, but I'm new to these things so any advice much appreciated.

 

Simon

[smiller]

Water. Doesn't make any difference. SOAKED the front/sides of the engine with it running, no difference.

Just FWIW, that isn't a comprehensive test of the HES wiring. After I experienced an engine failure in the rain (only to have the bike start and run fine the next day) I performed the same test, even spraying water under pressure directly into the front cover vents. I must have completely flooded the thing and I didn't experience a single hiccup, and in fact I could completely submerse the HES assembly in water once I removed it from the bike and yet it still seemed to operate perfectly with an LED tester. However, upon inspecting the hidden part of the HES harness (under the shrink tubing where it clamps to the HES mounting plate) I found the insulation almost completely disintegrated. My theory was that the shrink tubing was providing a pretty good seal and only water vapor was able to get into the problem area, making any tests with liquid water unreliable.

 

I'm not sure from your symptoms whether you really have an HES problem or not (sounds like more of a fuel-related problem to me), but if you have an 1100 and you are experiencing any intermittant run issues that don't have an obvious solution I'd suggest replacing the HES wiring proactively. This work will eventually need to be done anyway so it won't be a waste of time even if it isn't the cause and will at the very least eliminate one possibilty, and at best will fix your problem.

[T__]

Right,

 

just ridden the bike again. I want to be as sure as I can it's the hall effect sensors, so any advice please.

 

Water. Doesn't make any difference. SOAKED the front/sides of the engine with it running, no difference.

 

Heat. It DOES seem to get worse the hotter the bike gets

 

Fuel. Put fresh fuel in...no difference

 

injectors. Put some cleaner through the system, no difference. (although this doesn't mean the injectors are ok I suppose)

 

Riding the bike tonight, it runs ok at part throttle (say 3000 rpm in 4th gear) but open it up and it starts to accelerate, but after a couple of seconds starts to "gag" as if it's being starved of fuel.

I took the tank off today and looked at the fuel filter inside. It was stamped "2007" so it looks to have been replaced fairly recently. I didn't have a replacement so couln't change it,

It seems to me more like a fuel problem, but I'm new to these things so any advice much appreciated.

 

Simon

 

 

Simon, with it running decent at lower speeds then acting up AFTER A FEW SECONDS OF HARD ACCELERATION does kind of point to a fuel starvation problem..

 

You really can’t judge a fuel filter by age (or age-of-change) as all it takes is one bad tank of gasoline to plug a fuel filter.. Might even be a failing fuel pump,, or possibly as split fuel line inside the fuel tank dumping off some of the fuel pressure/volume..

 

Any chance you are seeing a vacuum inside the fuel tank when you open the fuel cap after a ride? If so, suspect your vapor recovery system is plugged up & engine vacuum is pulling a vacuum inside the fuel tank.. (this would be down the list a little as a good performing pump should be able to override the tank vacuum for a while,, but probably worth checking anyway)..

 

I guess unless you can find another smoking gun I would suggest pull the high pressure fuel line coming out of the fuel tank,, then run the fuel pump & check for a good pencil sized stream of fuel flowing strongly for a GOOD 30 SECONDS.. It sure wouldn’t hurt to rig up a fuel pressure gauge & monitor the high side fuel pressure while riding under hard acceleration..

 

Twisty

[ianboydsnr]

To my mind, its either the hall effect sensor, or its water in the fuel, or a blocked fuel filter, it could be a few others, but its more likely to be one of those

[bobmorris]

For what it is worth;

I had the same symptoms with my '96 R1100RT .

 

After many replacements of various parts it ended up being a faulty air temp probe in the air box.

 

An easy check if you have a friend with a similar bike. Just swap the probes (plug and play)

 

Bob

[T__]

For what it is worth;

I had the same symptoms with my '96 R1100RT .

 

After many replacements of various parts it ended up being a faulty air temp probe in the air box.

 

An easy check if you have a friend with a similar bike. Just swap the probes (plug and play)

 

Bob

 

 

Bob, that’s a good thought.. That AIT system defaults to around 70°f if the sensor fails or goes totally open..

 

As long as the intake air is close to 70°f then the computer won’t even know it has a problem.. But on the other hand IF the intake air is 40°f & the system has defaulted to 70°f it could lead to a lean condition (ONLY IN OPEN LOOP THOUGH).. In closed loop the computer looks only at the 02 sensor for fueling control.. The computer does use the AIT in closed loop for some spark mapping selection though..

 

On his problem showing up “AFTER A FEW SECONDS OF HARD ACCELERATION” could very well be an AIT problem as the system stays in closed loop for a few seconds on hard throttle up then drops out of closed loop & into open loop fueling where the AIT COULD have some effect on the fueling mixture..

 

As you say worth a look see anyway..

 

Easy enough to test with an ohmmeter..

 

Twisty

[Jim Moore]

Dude, fuel filter. Seriously.

[simonjrwinter]

 

 

Could be as simple as fuel you know.

I didn't at first associate filling up with the spluttering, but looking back I filled up about 10-15 miles before it started. Last night I filled up again with premium fuel from a different station. It spluttered for about the next 10-15 miles, but on the way home and now it (seems to be) as good as gold. No matter what I do, I CANNOT get the bike to splutter! red lined it, wound the throttle open in every gear, everything I can think of, and it's just not missing a beat! I took the bike for another long ride today, let it get really hot and still fine.

I'm really starting to wonder if it could have been as simple as maybe water in the fuel!

Watch this space!

 

Simon

[simonjrwinter]

Just to follow up, did a faultless 340 mile ride yesterday, didn't miss a beat! (bl**dy freezing though)

Simon

[Jim Moore]

Outstanding!

[ShovelStrokeEd]

I doubt it was water as the fuel filter will clog with that and stay that way. Bad fuel? Certainly. Oooops! Let me rephrase, it could have been water in alcohol mixed with the fuel and running it down got rid of the last of it so the new tank brought things back to normal. Free water will clog the filter, water absorbed by alcohol won't.