Broken down - twice in a month

[ricardo]

The story so far...

Late last Summer my 2004 1150gsa, with about 51k on it, started missing under load (overtaking, exiting roundabouts etc) but a pair of stick coils fixed it.
A fortnight ago, with 57k on it, it let me down on the A1. I'd been at cruising speed about an hour, when it felt like it missed a couple of times, then lurched about like it was running out of fuel and stopped. While lurching, the tacho needle bounced and the battery light came on. It wouldn't restart. Journey home completed with RAC and with the bike properly chilled after 90 mins on the back of a truck it restarted. It then carried on running even when it got hot.

At this stage I thought Hall Effect Sensor (apparently backed up by some research on here), so a new HES was fitted and all was well.

Today, after about an hour of Motorway/high speed A road it did the same thing. I've let it cool and limped it home. It juddered a couple of times but kept running.

The question is, what next? When it's running it runs sweetly. It's well serviced (new plugs, air filter, fuel filter done at same time as HES). Each time there's been more than 1/2 a tank of fuel in. Motronic? Injectors? I'm stumped and suspect that whatever I try next will be pricey...

Any ideas?

 

[flatdog]

Non expensive bits.
Check your tank breather isn't blocked.
Is your loom still tightly bound to the deadstock with cable ties if so you may have a broken wire in the loom.
Change your horn relay with the fuel pump relay - (a dodgy fuel pump relay stopped me so I swapped them over and all was well.....after I changed the £180.00 pump)

 

[MarkShelley]

I reckon the ignition switch wiring loom would be a good place to start. I had the same thing on my last 1100 and was convinced it was the hall sensors somwasted money replacing when it was simply a damaged wire.

 

[ricardo]

Thanks guys. I've already tried moving some of the wiring - no effect, but I'll try the relay and give the wires a better dose of looking at. So far only seems to have an effect after an hours riding though.


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[steve hughes]

Dont have an 1100/50 but just a thoughtif it happens after 60 mins of riding is is temperature or pressure. Electrical gremlins shorts etc appear at any time the wires touch, a good jiggle of the loom usually reveals these. The suggestion of a blocked breather sounds wise, but what could cause the. Ign light to come on? Does the fuel tank have a breather on , fuel starvation could be another option. Is there something like a Lamda sensor on these engines that is failing under temperature and causing the ign light as a warning?

 

[Steptoe]

Any ideas?

First thing Is to plug in a diagnostic and find out if any fault codes come up . See if anyone near you has a GS9111

 

[Slipperyeel]

This might be total red herring. So shoot me down by all means! But I wondered if the lambda sensor might be so badly coked up it eventually overheats (an an hour of constant riding for example) and upsets the motronic, causing the symptoms you mention?

 

[ricardo]

Thanks for the further suggestions. I've had it on diagnostics and nothing showed up (in fairness, that was pre-HES swap). There is a lambda sensor and I've never cleaned it. Providing I can get it out that's a cheap starting place. Intermittent faults are always a pisser. If I ride for an hour and then break down, you can guarantee I'll be nowhere near the diagnostics, unless I ride around his yard like a knob for an hour!

 

[flatdog]

Have you checked the tank breather yet?

In your op, the battery charge light coming on may be a red herring because your engine stopped running so the alternator wasn't charging anymore.

If it happens again when riding, immediately open the tank filler cap and see if she starts = breather blocked, if not at least youve ruled out that as a fault.

Keep it simple.

Another thought is double check you battery terminals are tight, clean and free of corrosion and in good nick, clean them properly - ditto in the starter motor.

 

[Burbs]

I had something similar on my 2000 GS.....ran lovely,but once it warmed up, a small bump in the road would blow a fuse.....turned out to be the wiring to the horn near the head stock had chafed a little - only did it when warm though!!

 

[ricardo]

Tinkering time tomorrow. I'll try all suggestions and update. Thanks


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[Steptoe]

Thanks for the further suggestions. I've had it on diagnostics and nothing showed up (in fairness, that was pre-HES swap). There is a lambda sensor and I've never cleaned it. Providing I can get it out that's a cheap starting place. Intermittent faults are always a pisser. If I ride for an hour and then break down, you can guarantee I'll be nowhere near the diagnostics, unless I ride around his yard like a knob for an hour!

If it's a lambda sensor problem the fault code would be stored and show up when reading the faults even if the problem isn't present at that time.

 

[ricardo]

Rode for an hour before checking anything - ran faultlessly. When checked, no fault codes at all. Plugs pristine - no soot. Breather not blocked - though I'm now riding around with my spare key in the fuel filler, if it stutters again I can open the filler and see if it makes a difference. Fuel and air filters replaced between breakdowns. Jiggled every wire I can find, turning bars, jumping on suspension, fiddling with side stand and clutch - no issues. At this stage it's become a 'let it develop' job. Any change and I'll let you know. Cheers