Sweetest running GS

[Spout]

Well, I now have the sweetest running GS on the planet.

Vibration free at all revs, strong pulling, no surging, happy to ‘pootle’ or be thrashed, pulls beautifully from 25mph in fifth! A real joy to ride.

Only trouble is it’s only like this for about 20% of the time. For the other 80% it runs like an asthmatic dog with a heart complaint fighting a jackhammer.

I’ve been trying to cure the bad running for some time now, and my tweeks (numerous valve clearance checks, injector checks, throttle body synching, TPS voltage setting etc) and replacement parts (fuel filter, fuel lines, air filter, spark plugs [various], throttle body sensor etc) have honed the bike to this fine state of tune.

Just wish I knew why it runs so rough most of the time.


Future investigations to include:

HT leads
Coils
Hall sensor
Any other sensor (bet there's loads!)
Loose wire (a few to choose from)
Replacement throttle bodies
Conversion to carbs and ditch that fecking FI system

Please feel free to add to the list................

 

[Tsiklonaut]

Simply put 1100 or 850 even better with Motronic 2.2 on in and it runs sweet forever

 

[ROJAZ]

Paul

Did you cure the slipping TPS sensor?

Has the bike been checked on the dealers motronic fault checker jobbie?

 

[Spout]

Mark,
I couldn't get a constant voltage, so I replaced the whole sensor.

It's the ignition system next. But have you seen the prices?

 

[Tsiklonaut]

Mark,
I couldn't get a constant voltage, so I replaced the whole sensor.

It's the ignition system next. But have you seen the prices?

No guarantee on bike?

 

[Tsiklonaut]

Put new air filter, or clean'n'lube if you have K&N

Check and oil completely throttle cables - take them out and if they are moving completely freely.

Sync throttle bodyes vacuum on all RPMs.

Check throttle bodyes - no corrosion inside, butterflyes moving freely without any dead spots.

Check spark plugs for right gaps and see if they're in right colour - very lightly brown but clean.

Check spark plug cabling.

Clean lambda sensor if you have one.

Check if the fuel pump gives the right pressure. Disconnect the tank outlet hose and direct it into graduated beaker, turn ignition on and off (fuel pump goes on for 5 secs)) measure how much the fuel got out into the beaker, multiply it with 12 and see what you get per minutes. The right pumping pressure should be more than 1850cc per minute.

Check all electrical system very carefully, not just the ignition stuff - all grounds good, no cables protection wore off due vibration, etc. See if you have about 13-14 stable volts (not jumping quickly more than +/-2 volts) in circuits while engine working.

Check if you have overoiled the engine - check the oil level.

 

[cookie]

if it's a twin spark, check the coil packs on the main plugs. try running with them disconnected.

 

[Fanum]

if it's a twin spark, check the coil packs on the main plugs. try running with them disconnected.

Thought that as well Cookie, after having both of mine fail due to....er, 'water ingress'

But I can't see it being intermmittant like that.....once they'd started going, they just got worse...

Still well worth a check though......find someone with another twin spark and borrow theirs.....

They're 80 quid each they are!!

(I happen to know Neil's got a brand new pair as well )

 

[sjwb]

Sounds like it is temperature related.
Check the sensor in the inlet tract and I believe there is one for engine / oil temperature. Have a look in the manual.

 

[cookie]

Thought that as well Cookie, after having both of mine fail due to....er, 'water ingress'

But I can't see it being intermmittant like that.....once they'd started going, they just got worse...

Still well worth a check though......find someone with another twin spark and borrow theirs.....

They're 80 quid each they are!!

(I happen to know Neil's got a brand new pair as well )

you might be right, but if it is the coils, then they run fine disconnected on the 2nd plug. it's the random sparking on the main plug that causes the problems.

easy check.

info courtesy of CW BMW & pikey dave BTW, it's all second hand to me.

 

[Spout]

My Adv is single spark.

Hmmmm....So is Caseys.......

....he doesn't know it yet, but as soon as he's back from the IOM his bike's due for a strip down. There's a few parts I need to borrow off him


Would plugging into a dealers 'code reader thingy' tell me if a sensor was playing up? and which one?

 

[cookie]

My Adv is single spark.

won't be the coil pack then.

sorry, i should have looked at your sig properly. i thought it was a 2004 ADV

 

[sjwb]

Quite so; the diagnostic equipment will look at each component and report its health. If a sensor of any sort has failed an appropriate DTC (diagnostic trouble code) will be logged and may be extracted by any generic scan tool. If it is an OBDII related failure - one which affects the emmisions of the vehicle - the logged DTC is universal and may be interpreted against a standard code set. For example P0131 is OBDII and refers to O2 sensor low voltage.

 

[(RIP) Kaister]

then they run fine disconnected on the 2nd plug

if they're manufactured like jap coils - the plugs are each end of the transformer ( coil ) winding and won't like running for too long on one plug,. ( open ended ) and will break down to earth thru the windings.