Starting problems and rough running back again

[DrAlf]

My starting problem that I originally mentioned here is back with a vengeance. I’ve spent the entire day trying to rectify the fault with no success whatsoever. I’d be extremely grateful if anyone who is more mechanically minded than myself (not hard) would be so kind as to look through my troubleshooting log and give me some insight into what could possibly be going wrong………………..

2000 R1150GS
TFI 1030
K&N
Remus Y piece and race can
28,000 miles.


The problem first started after I had been messing around with the tank – I removed the original tank and had been trying out a 1100GS plastic tank for size, I then refitted the original tank.

The first ride after this, the bike hesitated a little and later stalled as I tried to pull away from a set of lights.

The same day, I returned to the bike after parking it up for a few hours and it wouldn’t start.

The fuel pump primed itself and the engine would turn over but wouldn’t fire.

After trying to start it for some time, fuel started to pour out of the join between the two header pipes.

I removed the tank and inspected all connections and pipes – everything seemed fine

Checked for a spark – plugs were wet with fuel and there was a good spark

Sprayed WD40 on the side stand kill switch.

Bike started.

All was OK for a week or so although possibly running a little rough – occasional hesitation.

On the first long ride I noticed that the bike was hesitating more and more normally between 4000 – 5000rpm – felt like a fuel issue – bike sorted itself out after a while.

More cut outs and stalls at traffic lights but the bike instantly restarted on the first touch of the button.

This morning the bike wouldn’t start at all and had fuel pouring out of the header pipes again - literally creating a puddle of fuel under the bike.

I had a good look round the bike and noticed that the lock nut on the left hand throttle cable to throttle body wasn’t screwed down.

After reading some posts both here and on ADVrider I tried resetting the TPS – fuse #5 removed and then reinserted, ignition on, full throttle and released x 2, ignition off. Turn back on and again and press the starter button. Bike started but ran very rough. I’m thinking that the TPS reset wasn’t the cause of the bike starting and was simply a coincidence?

Go for a brief ride, bike running very rough, spluttering, lots of hesitation.

Get home, check the TB for balance. They’re way out – synch them up and off for another test ride.

Bike felt a little better but still suffered from extreme hesitation around 4000rpm + backfiring after every throttle off. Also felt like it would stall if I let the revs drop too low. On full throttle under hard acceleration bike seems fine.

Bike left for 3 hours – failed to start again, fuel pouring out of header pipes again.

Things I’ve tried:

Balanced throttle bodies
Checked that vent pipes from the tank are clear + ran the bike with the filler cap open
Checked that the throttle cables are seated correctly.
Valve clearances checked about 1000 miles ago.

Things that I suspect it might be:

Blocked fuel injector(s)
Fuel filter blocked
Coils
Fuel pump\fuel pressure regulator.

One thing is clear though, the bike is getting way too much fuel – surely fuel shouldn’t be coming out of the header pipes right?

Plan for tomorrow is to disconnect the TFI, reset the TPS and then try again.

The bike is well out of warranty and TBH I simply can’t afford to pay dealer prices for them to troubleshoot it. If anyone has any ideas or suggestions it would be greatly appreciated.

Many thanks in advance.


Adam

 

[Steve]

Certainly sounds a bit like problems I've had on Jap twins and 4's, where the coils have been cracked or damaged. Don't know much about the electrickery on the BM's though...

Could it be the Hall Sensors playing up? (Don't know anything about them either)

 

[Fanum]

Adam......can't help at all technically I'm afraid, but if I were you I'd cut'n'paste that exact question over to the ADvrider technical section.......they have some pretty smart cookies over there and it can't hurt to get as many opinions as possible.

 

[(RIP) Kaister]

Take the tank off again.
Go through the same things you did but look around very carefully.

Take apart and inspect all elec. connectors.

Is the o2 sensor still plugged in ?

Pull the injector elec. connector off while running.
Does one side make it worse or better ?

Swap injectors side to side

New plugs ?

plug caps seated etc etc.

Do another re-set - check your procedure

 

[littleredrooster]

When you say "good spark", how did you check?

If you checked with the plug in the open air, this could give a false result because, without any compression around it, a plug only needs about 12kV to spark; add 200+psi compression around it and it needs nearer 25kV. Wot you need is summat that will tell you if you have a spark under running conditions. A timing-light would be useful, for example, or one of those little neon-testers that I have (but I'm not sure if it would be visible on the bike, given that the plugs are buried a long way down the head).

I only say this because the problem seems to be electrical, given that you have puddles of unburnt fuel lying around.

Going back to basics, an engine needs 3 things to fire:
1. A supply of fuel and air in approximately the right quantity.
2. Enough compression to generate an explosion rather than a smoky burn.
3. A good enough spark to start the process, occurring at about the right time in the engine's cycle.

My bet would either be a) Coil(s) shagged or b) Hall sensor(s) shagged. The first could be eliminated with a swap from another friendly GSer; the second, I suspect, would require specialist knowledge from someone with more electrical ability than me. All I know of Hall sensors is that a poor output from them can lead to all manner of strange symptoms.

I'm still pondering on what else you could have disturbed when removing the tank, however......??

 

[littleredrooster]

Just another quick thought. Re-reading your original post, could it be that the engine is running on 'choke' all the time. The ECU has inputs from oil temp and (I think) air temp. If one or both of these has been disturbed, is the ECU being fooled into thinking the engine is permanently cold and requiring a rich mixture?? This would explain the excess fuel and the spark being extinguished.

Sorry - more questions than answers again!

 

[Frank Warner]

Fuel pooring out ... and you looking for fuel blockages

What you should be looking for are things that give too much fuel.

Forget the fuel filter. The fuel pump.


No.

Go look at the carbon canister if you have one - could be full of fuel.

Or is the fuel pressure regulator blocked? Is fuel returning to the tank .. if not then you probably have around 90 psi in the fuel lines rather than 30 ...

Blocked injectors? Well they usually bolck closed, but I supose some dirt could be traped in such a way as to supply excess fuel.. but to one cyclinder only. You could test this by removeing the injectors or teh throttle bodies so you can vie the injectors spray. Then just turn the key on and here the fuel pump whine for 5 or so seconds - that should pressureise the line - look for leaks from teh injector - the motor has no spun so there should be no sign of fuel into the inlet.

That is about that - as someone has suggested - check the temperature sensors air and oil - when the bike is cold they should both be about the same resistance?

 

[littleredrooster]

Another thought, following from what Frank has just said:
Are the fuel lines from the tank connected the right way round? If they were mixed up, what would be the symptoms? Anyone done this? Could the high-pressure fuel go the 'wrong way' through the regulator?

 

[Mick Fagan]

I would agree with red rooster about the fuel lines being attached the wrong way around.

When attached this way the bike runs like a dog and fuel seems to coming out of all kinds of orifices.

The bike will run and be rideable, just, but that is about it. Also they will backfire a fair amount.

Seen it done twice and each time exactly what you describe happens.

Mick.

 

[(RIP) maverick]

Another thought, following from what Frank has just said:
Are the fuel lines from the tank connected the right way round? If they were mixed up, what would be the symptoms? Anyone done this? Could the high-pressure fuel go the 'wrong way' through the regulator?

If the two fuel lines on the right hand side is connected the wrong way around it won't start at all I found with mine. Something really stupid but have you checked that the oil breather pipe is not bend or trapped between something

 

[DrAlf]

Thanks for all the suggestions and help – very much appreciated. I spent another day working on the bike yesterday and also spoke to Motorworks who were incredibly helpful.

Yesterday I removed the fuel tank and cleaned up all the electrical connectors that live under the tank. I then removed the coil unit and gave it a good clean up. I inspected all the fuel and breather lines that mount to the fuel pump plate under the tank – all seemed fine. After refitting the tank, and after a number of attempts, the bike started. It ran a little rough to start with but then settled down OK. I went for a long ride and the bike appeared to be fine – no coughs, no stalling and no hesitation anywhere. The true test will be a cold start later today.

I’m hoping that it was just down to a dodgy connection on the coil unit but I suspect that I haven’t seen the last of the problem.

Motorworks reckoned that these sort of problems are most likely caused by coil failure or Hall sensor failure. If the problem comes back I’m going to inspect the Hall sensor.

The fuel lines on my bike are fitted with quick disconnects – the QD’s are fitted in such a way that it is impossible to connect them the wrong way round. Would have been nice if it was them though.

Thanks again for all the help.

I’m sure I’ll be back soon!


Adam