Concern with Cold Starting

[ClassicBertha]

Hi All,

I have a '99 plate R1100GS, under 30K miles, and I am not happy with starting the bike when cold. It sounds lumpy initially and then when the revs are lifted it smooths out. The concerning thing is the strong smell of petrol when it's revved. Once I pull away it is fine and when it is warmed up it rides likes a dream. This has been a problem for a while now, but I am getting a bit fed up of it now.

It has been serviced in the last 500 miles and the fuel filter and fuel lines have been renewed as there was a slight weep at the plate on the tank.

I would like to check this out but diagnosing problems is not my gifting. Could anyone give me some guidance on what to check with this please?

Any advice appreciated. (Timmy's Rules please, if it's applicable to tech questions and not just FS&W)

Regards

Brad

 

[chad]

could be worth having the injectors
checked,cleaned or replaced

better minds will be along with more advice im sure

 

[Flipfly]

Personally I wouldn't worry about it being lumpy on start up without fast idle, it's a feck off big twin, that's why it has a fast idle. Smell off petrol could indicate there is still a leak somewhere, it wouldn't need to be much.
If it's not a really strong smell it's probably just rich thanks to the cold weather.

Start by resetting the tps. Turn on ignition, smoothly rotate throttle to wide open and close three times, turn off. Then start the bike, see if that helps

 

[richierex]

Personally I wouldn't worry about it being lumpy on start up without fast idle, it's a feck off big twin, that's why it has a fast idle. Smell off petrol could indicate there is still a leak somewhere, it wouldn't need to be much.
If it's not a really strong smell it's probably just rich thanks to the cold weather.

Start by resetting the tps. Turn on ignition, smoothly rotate throttle to wide open and close three times, turn off. Then start the bike, see if that helps

Isnt that for the 1150. not sure it works on the 1100 motronic!

 

[DrFarkoff]

Is the Fast Idle (aka "Choke) control actually moving the throttles

Try pressing the start button with about a cm of open throttle

What happens then??

EDIT judge the throttle opening to give you about 1250 "ish" rpm

If they are moving the throttle valves very slightly open then you may look into checking the setting of the TPS throttle position sensor

 

[Flipfly]

Isnt that for the 1150. not sure it works on the 1100 motronic!

It's the same on the 1100 and the 1150 as far as I know they use the same system

 

[ClassicBertha]

Thanks for the replies so far

Hi All,

Thanks for the replies so far. I have wondered about the injectors. What do I look for to know whether the injectors are knackered or not? or is it a case of just replacing them?

Flipfly- Resetting the TPS using the method you have mentioned. Will doing this create problems, or if it is something else, won't make any difference?

Regards

Brad

 

[DrFarkoff]

Flipfly is re-setting the Motronic engine management unit not resetting the TPS

You need to "check" the TPS If it is out of spec it will cause rough running Basically it tells the ECU what angle the throttle butterfly is at. When at rest the setting should be 0.375 mv or thereabouts

BUT Before you go racing looking for a multimeter Do the basics first! Did you check to see when you pull the "choke" On if the throttles open at all?

When the System is cold it overfuels by maybe 30% If the throttles are not opened to allow more air (or oxygen) in then only so much can be burn't and it runs like a bag of schite as it's too rich

That is why I mention trying to start it with the throttle cracked open maybe a cm at the twist grip to allow more fuel in and to see if it is smoother?

You may end up just adjusting the fast idle control cable

 

[Flipfly]

I knew it reset something

Doesn't the procedure also reset the motronics understanding of the closed throttle/fully open throttle info that it gets from the tps though
I thought the whole point of it was so the system understood fully open/fully closed throttle openings?

If the bike is running fine when it warms up a little, I would seriously doubt the tps is out as that would cause rough running all the time.

I still think that there's not much wrong. Mine coughs and splutters on a cold morning but a little touch of throttle and smooth as ya like, absolutely fine after a few seconds.
Every one I've had has been the same.