[RdRcr150]

This a problem for all you top tuners out there in internet land.
2002 Honda 919, stock except for slip-on.
180PSI cyl 1 thru 4 compression, 2-3% leakdown across.
valve clearances correct.
cam timing correct.
new fuel injector #2 cyl,new starter valve #2. (only cyl that collects gas)(yes it will sometimes hydrolock)
new plugs, new ignition coil 2 & 3 cyl.
correct ohm reading pulse coil.
in dealer mode no faults.
new air cleaner.
fuel pressure regulator is ok according to manual.
fuel pump is working correctly.
throttle bodies cleaned, starter valves sync'ed.
Overnight #2 cyl will fill with gas, all plugs will foul upon trying to start.
clean plugs bike runs great until it sits overnight, then the entire process must be repeated.
I've only been working on bikes for 40 plus years, taught motorcycle mechanics for 20 years and this puppy has me stumped. If I had acess to another ECU I would try it but, I don't think it's an ECU problem cause once the plugs are cleaned it runs great until it sits for a period of time.
One free atta-boy to anyone who can lead me in a direction I haven't been.

[ucfmotorcycle1]

Somethings keeping that injector open. Could be electrical. Possibly two leaky injectors? I've seen two components go bad back to back before. Try cleaning everything as you say and then disconnect the battery and let it sit overnight. If it happens again this eliminates an electrical/ECU problem. If it runs fine then theres your problem.

[msalser1000]

Have you checked all you grounds. I had a 600rr with the same thing. The grounds were all coroded and it was making an injector stay open.

[denzee]

Could it possibly be one of the other injectors? Maybe it's crossing over somehow through a balance tube or something. Try unplugging each injector separately over 4 nights to identify another faulty injector signal. Failing this, remove the injectors and let them hang outside their ports plugged in and watch. I'm not familiar with the starter valves but you can maybe do something similar to isolate. Seems the problem is more likely mechanical than electrical since the key is off when this occurs and it runs fine after. Good luck and let us know Rd.

[nedro]

I'll take response #2 and #3 for a thousand Alex.

You will find the problem if you check those thoroughly.

And response #4 just takes all the fun out of it by telling you how to diagnose it. In Cartman's voice, "That's a bad Densee."

[robert mcvey]

it is definitly the gigling pin .

[RdRcr150]

it has new gigling pin and muffler bearings

[RdRcr150]

Turns out to be a bad fuel pressure regulator...bleeding fuel into the vacuum line.

[denzee]

Originally Posted by RdRcr150

Turns out to be a bad fuel pressure regulator...bleeding fuel into the vacuum line.

How did you find the problem RdRcr? It must be tapped into #2 to get vac or in the vicinity. Glad you found the prob. I thought the reg checked out ok.

[RdRcr150]

According to the service manual it is working fine...however when the system is powered up it leaks fuel into the vacuum line on the backside. The service manual only checks peak pressure not for diaphragm failures. A guy on the WERA board had a VTX that did the samme thing and gave me the heads up. All you have to do is power up the system with the vacuum line disconnected and the problem becomes evident.

[denzee]

As Maxwell Smart always said " the old fuel pressure regulator leaking fuel through the diaphram trick. The second time I've been fooled by that one". A little humor. Glad you nailed it RdRcr.

[ratdog]

it's the same on many honda's

# 2 fills because it's low when the bike is leaned over

if #2 fills, check your diaphragm

just had the same thing happening on a 79

[RdRcr150]

It's one of those problems that have you saying,"Oh man how did I miss that?" In hind sight it frustrates me as a professional mechanic, because it seems so simple and apparent afterward. It does make you think about your processes and self analyze your procedures. In the end it makes me a better mechanic.