Fuel line leak causing no ignition?

[RussInParis]

In doing a bunch of service on our 2008 R1200RT (all oils + filters changed, rebuilt abs pump re-installed, new brake rotors+pads plus lots of brake fluid flushing, new alternator belt, valve clearances adjusted, new plugs) with about 63k kms upon startup only one cylinder is firing (right side is NOT firing). Checked spark plugs on that side and noticed a fuel leak just before the injector (see photo). It's not spurting out, but definitely seeping out.  No errors reported by GS911 except for a parking light which probably wouldn't affect the spark plugs ;-) 

 

Question 1: Can a leak like this cause a lack of ignition?  Seems unlikely to me, but I'm not sure where to troubleshoot.  Can I do the old 'pull the spark plug out and hold it against the cylinder head to see if it sparks' thing or will this destroy some electronic ignition module?

 

Question 2: Anything special about the fuel line and/or replacing it?  Can I just order 8mm ID fuel line and expect to easily change this myself, taking out the old and cutting the new to length?

 

Thanks.

 

[dirtrider]

28 minutes ago, RussInParis said:

____ upon startup only one cylinder is firing (right side is NOT firing). Checked spark plugs on that side and noticed a fuel leak just before the injector (see photo). It's not spurting out, but definitely seeping out.  No errors reported by GS911 except for a parking light which probably wouldn't affect the spark plugs ;-) 

 

Question 1: Can a leak like this cause a lack of ignition?  Seems unlikely to me, but I'm not sure where to troubleshoot.  Can I do the old 'pull the spark plug out and hold it against the cylinder head to see if it sparks' thing or will this destroy some electronic ignition module?

 

Question 2: Anything special about the fuel line and/or replacing it?  Can I just order 8mm ID fuel line and expect to easily change this myself, taking out the old and cutting the new to length?

 

Thanks.

 

 

Morning   RussInParis

 

Question 1: Can a leak like this cause a lack of ignition?  Seems unlikely to me, but I'm not sure where to troubleshoot.  Can I do the old 'pull the spark plug out and hold it against the cylinder head to see if it sparks' thing or will this destroy some electronic ignition module?--- It could but unless it is squirting out you should have SOME fuel injection on that side.  (as a test) You might put a little sealer on that split, then clamp a split piece of rubber hose over that tubing split, then see it will fire off on that side.

 

Question 2: Anything special about the fuel line and/or replacing it?  Can I just order 8mm ID fuel line and expect to easily change this myself, taking out the old and cutting the new to length?--- Yes, very special, technically that hard plastic high pressure plastic line isn't replaceable  by itself. It is part of the entire fuel pressure regulator assembly that is quite difficult to replace. 

 

Some have cheated & clamped on rubber (high pressure fuel injection rated)  hose.  But that is kind of an iffy repair as the high pressure hose will clamp on the injector tit OK but unless you access & go all the way back to the pressure regulator outlet tit there is no good way to clamp the rubber hose onto that hard plastic high pressure injector line. (remember you are working with over 50 psi of hot fuel here), a small pin hole leak could get you a nice intense fire.  

 

[RussInParis]

Thanks for the info. I think I've seen some of these assemblies on some used parts sites.  I guess I thought you should be able to replace just one tube at a time.  *sigh*

 

No spare hose clamp to test at the moment, but really it's only seeping, not spurting, so really find it hard to believe this is causing the misfiring/lack of firing, but it's worth a try, so I'll try that tomorrow.

 

Assuming the clamp makes no difference, any hints to troubleshooting the ignition?  What are the weak points, the coils?  With two spark plugs, I would think that both coils wouldn't go at the same time so probably something else...

[dirtrider]

1 hour ago, RussInParis said:

Thanks for the info. I think I've seen some of these assemblies on some used parts sites.  I guess I thought you should be able to replace just one tube at a time.  *sigh*

 

No spare hose clamp to test at the moment, but really it's only seeping, not spurting, so really find it hard to believe this is causing the misfiring/lack of firing, but it's worth a try, so I'll try that tomorrow.

 

Assuming the clamp makes no difference, any hints to troubleshooting the ignition?  What are the weak points, the coils?  With two spark plugs, I would think that both coils wouldn't go at the same time so probably something else...

Evening  RussInParis

 

You did so much to it all at once your problem could be about anything from a tight valve (did you tighten any more the a 1/4 turn  when you did the valve check????

 

Otherwise it could be a stick coil, they usually don't both go out on one side at the same time  but possibly one was already going out.  

 

You probably should run a cranking compression test just to verify enough compression. 

 

Verify that the right side throttle body cam is not broken (it can happen on older 1200 bikes) verify that the R/H throttle cable is not pulled part way out of the throttle body bracket seat or pulled partially out of the throttle cable splitter box.  

 

It is difficult to access & view but if you can, verify that the R/H throttle body cam is FULLY returning to it's idle stop screw (if the cam is held open, even a  little, that can kill that side cylinder firing at idle)  

 

 

[RussInParis]

Had a look with a friend today. Verified the valve clearance is correct, not too tight.  Verified there is spark on both spark plugs.  Pulled the injector and verified that fuel was spraying out (also in a nice conical pattern, so nothing blocked there); o-rings etc still look fine on that as well.  Bike runs on one cylinder, won't idle, but we could keep it going steadily at 1800-2000 rpms which we did for several minutes with no change.  Afterwards right side exhaust still cold.

 

I don't have a compression tester, but the handy 'finger over the spark plug hole' while manually turning over the engine did sense pressure buildup.

 

checked with GS911 again, no fault codes except external air sensor and that pesky parking light bulb which hasn't repaired itself since yesterday. ;-)

 

Have not verified the throttle body cam or cable or cable splitter box.  These are things I've not done so will need to hunt for the "how-to" instructions on the net.  I did need to temporarily remove the idle actuator in order to get at one of the bolts to remove the ABS pump last week, but it looked fine and went back in fine.

 

However, even there it seems that it should still fire and idle, no?  

[RussInParis]

Ok, found it!  The right side throttle cable had been pulled slightly out of the cable splitter box.  I was trying to inspect the throttle body cam and noticed that it was not against its' idle stop, traced the cable and found it was pulled out of the splitter box. A brief adjustment back to where it was supposed to be and bike started right up on both cylinders running smoothly. 

 

Amazing such a small and simply misalignment presents as one cylinder not running at all...

 

Still have the fuel leak to deal with. I will try a hose+clamp method to stop it for now.  The fuel distribution assemblies I've found for sale on line sometimes have a flexible hose section with two clamps and sometimes do not; not sure if this was original or added after.  I think I need to take off the gas tank to see the entire assembly.

[dirtrider]

17 minutes ago, RussInParis said:

Ok, found it!  The right side throttle cable had been pulled slightly out of the cable splitter box.  I was trying to inspect the throttle body cam and noticed that it was not against its' idle stop, traced the cable and found it was pulled out of the splitter box. A brief adjustment back to where it was supposed to be and bike started right up on both cylinders running smoothly. 

 

Amazing such a small and simply misalignment presents as one cylinder not running at all...

 

Still have the fuel leak to deal with. I will try a hose+clamp method to stop it for now.  The fuel distribution assemblies I've found for sale on line sometimes have a flexible hose section with two clamps and sometimes do not; not sure if this was original or added after.  I think I need to take off the gas tank to see the entire assembly.

Morning  RussInParis

 

Glad it turned out to be  something simple. (usually is if they ran good before a service but not so good after a service)

 

There is a difference in the pre (before) 08/2006 build date fuel pressure regulator & the post (after) 08/2006 build date  fuel pressure regulator. Seems to be more hosing on the pre (before) 08/2006 fuel pressure regulator so you probably need to verify that the one you are looking at is for a  2007 & up hexhead 1200RT.