Poor running, help needed

[Sempione]

I'm giving up.
Does someone in the Worthing or Woking area own a 911 diagnostic tool or know an uncomplicated dealership where I can get the fault codes read without an appointment?

My single spark R1150GS is running poorly. It used to tick over at about 1100rm but is all of a sudden at just under 1000rpm and the engine dies if I don't give it some throttle. When I hold my hand over the exhaust it feels like the engine misfires occasionally and I can see the rpm change slightly when this happens.
The engine feels quite rough at higher rpm.

Things I tried so far without success:
- Both cylinders get hot.
- The right hand throttle cable is seated at the throttle body.
- The grooves on the TBs where the throttle cables sit in are clean.
- Rubber bungs on the throttle bodies are in good condition,
- New spark plugs,
- New air filter,
- Rocker endplay and valve clearances checked,
- Throttle bodies synchronised,
- Pulled out the throttle cable junction box to make sure the cables are seated as I changed them a couple of weeks ago,
- Throttle bodies synchronised again,
- Checked spark, both sides seem ok.
- Measured ignition coil resistance (primary 0.6 Ohm, secondary 6.9 kOhm),
- Measured resistance of <1year old HT leads (6.9 kOhm), doesn't change when flexing,
- Checked fuel injectors by sticking them in a jar, both seem to work ok as I expected because they were recently professionally cleaned,
- Checked throttle position sensor (0.36V at idle),
- Disconnected Lambda probe, still runs like s**t
- Checked compression (130psi left & 135 psi right with COLD engine),
- Checked for air leaks at the throttle bodies. Noticed rpm rise by a tiny amount when I douse the left TB in brake cleaner. I pulled the left TB and inspected the inlet manifold. It didn't have any visible damage so I refitted it while using a new O-ring. I ordered a new inlet manifold to be on the safe side.

As I'm still suspicious of the Lambda probe and don't know a way to test the Hall effect sensors I want to get the fault codes read.
I phoned a dealership on Saturday and was told to come in. When I arrived the mechanic had already gone home. Phoned them today and get told that I could have an appointment in a week.

Any advise for further testing or things I might have overlooked would be greatly appreciated.

Thanks,
Niki

 

[Welshman]

I'm giving up.
Does someone in the Worthing or Woking area own a 911 diagnostic tool or know an uncomplicated dealership where I can get the fault codes read without an appointment?

My single spark R1150GS is running poorly. It used to tick over at about 1100rm but is all of a sudden at just under 1000rpm and the engine dies if I don't give it some throttle. When I hold my hand over the exhaust it feels like the engine misfires occasionally and I can see the rpm change slightly when this happens.
The engine feels quite rough at higher rpm.

Things I tried so far without success:
- Both cylinders get hot.
- The right hand throttle cable is seated at the throttle body.
- The grooves on the TBs where the throttle cables sit in are clean.
- Rubber bungs on the throttle bodies are in good condition,
- New spark plugs,
- New air filter,
- Rocker endplay and valve clearances checked,
- Throttle bodies synchronised,
- Pulled out the throttle cable junction box to make sure the cables are seated as I changed them a couple of weeks ago,
- Throttle bodies synchronised again,
- Checked spark, both sides seem ok.
- Measured ignition coil resistance (primary 0.6 Ohm, secondary 6.9 kOhm),
- Measured resistance of <1year old HT leads (6.9 kOhm), doesn't change when flexing,
- Checked fuel injectors by sticking them in a jar, both seem to work ok as I expected because they were recently professionally cleaned,
- Checked throttle position sensor (0.36V at idle),
- Disconnected Lambda probe, still runs like s**t
- Checked compression (130psi left & 135 psi right with COLD engine),
- Checked for air leaks at the throttle bodies. Noticed rpm rise by a tiny amount when I douse the left TB in brake cleaner. I pulled the left TB and inspected the inlet manifold. It didn't have any visible damage so I refitted it while using a new O-ring. I ordered a new inlet manifold to be on the safe side.

As I'm still suspicious of the Lambda probe and don't know a way to test the Hall effect sensors I want to get the fault codes read.
I phoned a dealership on Saturday and was told to come in. When I arrived the mechanic had already gone home. Phoned them today and get told that I could have an appointment in a week.

Any advise for further testing or things I might have overlooked would be greatly appreciated.

Thanks,
Niki

Hall sensor is usually all or nothing not running kark...

 

[roddy]

have you checked the condition of the o-rings on the BB screws and if the corresponding openings are clean and dirty free ?

 

[DollyRocket]

Can you get to Steve at Liphook motors?

Otherwise, Bahnstormers in Alton? I had mine on their computer last week, £10 to diagnose a similar fault to yours, cutting out at roundabouts etc. Showed up as TPS set incorrectly - adjusted there and then and the bike has never run sweeter!

I think Steptoe has a GS911 thingy (about 20 mins from Woking)? The Lambda sensor shouldn't have too much effect unless the engine is at a fixed throttle opening (or idle) AFAIK.

 

[Colban]

How many miles has the bike done?.
When was the fuel filter changed (miles ago)?.
Have you checked for blocked breather/overflow pipes?.(does it run better with filler cap open).
Water in the fuel system?.
Is the TPS voltage set to approx 0.37V.

 

[Sempione]

Thanks for the help.

The bike has done 85k miles.

I checked the BB screws and the O-rings were fine. I cleaned the openings with some brake cleaner when I had the TB off the bike.

The breather seems to work. I don't hear anything when I open the fuel cap after a normal run and don't notice a difference with open cap. The overflow pipe isn't blocked so there shouldn't be a way for water to get into the tank.
I changed the fuel filter about 7k miles ago and drained the tank. Might open it again to check the fuel hoses, drain it again and change the filter just to eliminate this possibility.

TPS voltage is set at 0.36V.

I'll give it another go tomorrow to see how it runs off idle and then decide where to take it.

Cheers,
Niki

 

[Sempione]

Just had the motronic fault codes read.
"No fault code present".

Back to square one.

 

[Steptoe]

. It used to tick over at about 1100rm but is all of a sudden at just under 1000rpm and the engine dies if I don't give it some throttle.

- Throttle bodies synchronised,

If you've balanced the throttle bodies why does it idle at under a 1000rpm.

Back out the idle adjusters a half turn each to increase the idle.

Have you checked the resistance across the injectors ?

The 1150 fault readings aren't very advanced. i.e. the air temp sender working parameters are 0 degrees to 50 degress - now it could be reading 0 degrees when it's 50 degrees and vice versa, but it won't register a fault as it'll be working within it's parameters.

And another thing - I'm not saying it's your air temp unit, i'm just using it as an example.

 

[Sempione]

Hi Neil,
The idle speed just won't rise. I just turned both idle adjusters out an additional 1.5 turns but it has no effect on idle speed.

I didn't check the resistance across the injectors. How much should it read?

I got a new rubber inlet manifold today, fitted it and tested again for air leaks with brake cleaner. The revs still rise.
Could a leaking head gasket be the culprit?

I'll try locating the air leak and will do another compression test with a hot engine.

Cheers,
Niki

 

[Sempione]

No wonder the revs rise when I spray the left throttle body/cylinder with brake cleaner.
I connected a hose acting as a snorkel to the air inlet and repeated the test. Behold, the revs no longer rise.

Got a compression of about 142psi on the left cylinder, just under 150psi on the right.

Resistance across the injectors is 16 Ohm.

 

[Sempione]

I tried a couple more things over the weekend that didn't cure the problem:
- Got a new HT lead and tried it on both spark plugs
- Changed the ignition coil
- Tried another left throttle body with throttle position sensor (0.37V).
- Tested oil temperature sensor, resistance changes with temperature
- Tested air temperature sensor, resistance changes with temperature

I pretty much double checked everything I had tried earlier.
I cleaned the air bypass on the throttle bodies again but the idle adjuster screws still have no effect on idle speed.
Would this suggest that it is running way too lean?

Getting the Lambda probe out was a bit of a pain. One of the screws holding the collector box on the main stand bracket didn't move and I stripped the head. I had to drill it out.
The tip of the probe is white. According to the information I found online this suggests silicone contamination but I have no clue where that would come from. I haven't used exhaust sealant upstream of the probe.
I should get a Lambda probe today.

 

[D6]

cant see it being the lambda, mine runs fine without one??

 

[Steptoe]

cant see it being the lambda, mine runs fine without one??

Thats why it could be his lambda - sending erratic signals

You can plot the lambda on the GS911.

 

[NeilDD]

I tried a couple more things over the weekend that didn't cure the problem:
- Got a new HT lead and tried it on both spark plugs
- Changed the ignition coil
- Tried another left throttle body with throttle position sensor (0.37V).
- Tested oil temperature sensor, resistance changes with temperature
- Tested air temperature sensor, resistance changes with temperature

I pretty much double checked everything I had tried earlier.
I cleaned the air bypass on the throttle bodies again but the idle adjuster screws still have no effect on idle speed.
Would this suggest that it is running way too lean?

Getting the Lambda probe out was a bit of a pain. One of the screws holding the collector box on the main stand bracket didn't move and I stripped the head. I had to drill it out.
The tip of the probe is white. According to the information I found online this suggests silicone contamination but I have no clue where that would come from. I haven't used exhaust sealant upstream of the probe.
I should get a Lambda probe today.

You have'nt bought your fuel from Tesco's have you
I know they have lots of problems round this way (Nth Herts) to the extent that local car dealers will tell you that using Tesco will invalidate your warranty, due to the number of Cat and Lamda sensor failures they get....

Neil

 

[Sempione]

I usually fill up at Total or BP, used ASDA petrol about twice but never used Tesco fuel.

The new Lambda probe didn't change a thing.

I guess I'll have to buy another train ticket tomorrow. just spent 3.5 hours on trains and platforms to get home from work.

 

[(RIP) Kaister]

just book it in at steptoes and stop wasting time

 

[Sempione]

I started to see it as a challenge and good learning experience (and reminder to get a second bike ).
Steptoe would be my first choice if/when I surrender.
I'd even carry my gear box to him in a sportbag on public transport.
(Neil, cheers for the lift to the station. That thing almost killed me on my way to you.)

Things tested lately:
- Fitted a spare injector on each side without change.
- Drained the fuel tank using the fuel pump. Output of the pump seems ok.
- I found no damage to the internal fuel lines.
- The fuel filter is not split or blocked.
- Checked the hall effect sensors and voltage changes between 12V and 0V as it should when turning the engine slowly over at the alternator pulley.

The next possibilities I want to eliminate are a (slowly) failing fuel pump and the pressure regulator. I'll know more once I get hold of a fuel pressure gauge.

 

[Sempione]

Recent development:

The old Hall effect sensor tested ok but I tried a used one (with 13k miles) anyway. No change.
Changed the fuel pressure regulator. No effect.
Finally got my hands on a fuel pressure gauge and the pressure is stable at 3 bar.


Neil, PM incoming.

 

[rudiemoto]

change the fuel filter
just had a rsvmillie runs poo did all jobs that i would think ,then change fuel filter runs sweet
only had 14669miles on clock
on 51 plate
hope this helps if not just trade it in
there r some gs type bikes out there

samtheman on my old gsa cb500 se

 

[Sempione]

Replacing the fuel filter didn't help.

I just noticed that the spark plugs I fitted 200 miles ago look very different (shown after 40mile run).

Not sure of much anymore but I guess I'll have another look at the injectors, ignition coil and HT cables.

By the way, I'm tempted to get a CB500S. I'd prefer something like a TDM850 but I'm hoping to lure my girlfirend into motorcycling.