Team, really need your help. I'm trying to get a bike started of a friend which is giving us quite a few issues. We have found issues with the fuel pressure regulator as well as with the pump. Both have been replaced with working spares. The Air Mass Meter measures OK and the vane is free. The bike seems to flood continuesly during starting. We have had the rail/injectors out and watched it spray good, however when you release the starter button the injectors continue to flow (Not pulsing, but they remain open as long as long as you hear the pump run. They stop as the pump stops and the fuel rail stays on 2.5 Bars.
We have checked the complete troubleshoot page from Bert's main site and all measure/functions OK.

We managed to get the bike running shortly with a continued start with closed choke and slightly opened throttle, but it stalled as soon as we turned the throttle further

Any advise/experience appreciated.

Cheers, Rene.

interesting issue renez, sounds like an FI computer issue .
have you cleaned all the connections between the ignition control unit (under the tank) and the computer under the seat ?

i would imagine that the trigger assemblies send pulses to the ignition control unit which processes the signal then sends the pulse to the fi computer .

would love to see what this turns out to be

Yeah, mate, all clean and measuring OK. We finally gotthe bike to run, but still think the issue is not solved.

Cheers, Rene

Last spring, when restarting the bike after our long winter I go the same problem. I traced the problem to the connection of the FI computer.
What was bad is that the excess of gas sipped through the piston rings and 'polluted' the oil.

Bert, fully appreciated. The oil will need to be changed.
So you also had a problem with the injectors remaining open??
I'm just wondering about the injectors remaining open for the duration of the fuel pump 'overrun', which would mean the engine is always is flooded after not starting at the first try. We have cleaned the connector of the FI computer, but will have another go at it.
Cheers, Rene

Check the voltage across the injector with a bulb, it should pulse on and off it sounds like yours is continuous. As Bert says clean the FI computr plug and socket with deoxit no abrasive at all just dexit on the sponge applicator.
Regards,
K-BIKE

Cheers Mate, we did that and all looked great - light pulsing and injectors 15/16 Ohm. Continuity of the injector loom tested to the ECU as well. Plug has been cleaned, but we'll revisit all that.

But again, what puzzles me is that the bike continues to inject after the starter button is released, during the overrun of the pump. The pressure in the system remains at 2.5 Bar. I would really like to hear from someone who has had the injectors out of the block and tested them if they had a similar experience and how they solved that.

All, thanks for thinking along, this has really puzzled me!

Problem:

Bike will not start
after having been down, once in a while a backfire. Continued
starting will result in fuel in the exhaust. On occasion it sounds as
if she will pick up, but dies again. This whilst playing with the
throttle a bit. We had her running for some time on Sunday, but the
next day it was same old.....

What we have done:

Check battery voltage -
OK

Check injector pulse
with LED – OK

Check loom between
injectors and ECU – OK

Check injector
resistance – OK (16 Ohm)

Check injectors outside
of engine – OK (bit of doubt about the amount, but they all
'squirt' – OK

Check fuel pressure –
OK (after change of pump and fuel pressure regulator)

Check fuel hoses – OK
(part renewed)

Check fuel return to
tank - OK

Check coils – OK
(Prim 2.5, sec 12.5K)

Check FI computer –
OK (replaced with known good part, same issues remain)

Check the spark plugs –
OK (the 'tell-tale light' blinks)

Check the AMM – OK
(Flap moves, electrically measured and is OK)

Check connection
between AMM and plenum – OK

Check cooling water
temp sensor – OK (2.5K at 20C)

Cleaned all connectors
in sight

Still to do:

Check compression,
however bike has ran OK

Measure amps during
starting


Ceremonially burn the
bike!

On completion:

Oil
change

Anything we might have missed? Thanks!

Renez,
Is it not a sticky injector relay?

hmm quite a list rene .... i dont know what is the best way to check ...but did the plug tops or ignition outputs or coils get swapped around ....kinda sounds like a timing to fire issue to me after seeing your list .......

i had almost a similar issue one day (although in the car still an inline 4)
washed it and got massive cross firing through the distributor and actually blew a hole between 2 and 3 cylinders head gasket.... anyhow long story short .....i had replaced all but couldnt get her to fire up ...lots of fuel smell though and some times a hint of running ok but would suddenly die ....followed timing sequence and i had swaped ignition leads over on a couple of cylinders by accident .

hope you get her going mate

Thanks Team, I'll have a look at the leads and the relay. As you've probably have noticed I'm out of ideas.....

Found it! After swapping the coils, HT leads and sparkplugs from my bike onto the bugger it started on the first push. Slowly swapping original parts back we found eventually all spark plugs duff Never seen all plugs go off in one go, but there it was. Same plugs (Bosch X5DC) did not work in my bike. The owner of the bugger quickly got some NGK D7AE's and we had the bike running again. I'm happy we finally found it, but am still a bit puzzled about it. Adjusted the bike with the prof.sync software and she was running sweet. Still need to do the CO etc. but we're getting there.

Re the plugs, I have one of those parts that fit between a spark plug and the cap which lights when a spark plug fires and it worked! However the spark can't have been strong enough to ignite the mixture.

Thanks for all your help/support!

yay ....good work rene ....glad you finally put your finger on it


hmmm something to add to the tools "carry" list .....spark plugs

Excellent Work Rene, you at least know there will be no bad connections for many a year!
Regards,
K-BIKE

Well done ReneZ,
Your ternasity has paid off and also produced a good flow chart of working out problems a simple spark plug, as charlie said I think I will add a set in the spares packup.

BIG D

I`m a bit confused here.......
Just got a service kit from Motorworks.
The plugs included are Bosch X5DC.
I`ve allways used NGK`s.
I`m giving the Bosch`s a try and keep the old ones incase......
Cheers,Wikur!

Wikur, those were originally fitted (the Bosch) IIRC so should be good. I think something might have happened when the bike was dropped. But from now on I will always keep a spare set on the bike!