Gen II DOA

[S76]

Sorry I don't know how to make this short and still include pertinent data.

Parked the bike in a warm dry basement for the winter. Everything was fine. Started it a couple weeks ago. Started perfect, idled and ran perfect. After a ride of 10 or so miles the engine started cutting out above 1/2 throttle. It would die, go, die, go. The engine was a 100% cut off, not a miss, and cycled bad to good 2 or 3 times per second. Yeah, quite violent at full throttle. If I let off to 1/4 throttle or less it was fine. Seemed to get worse the longer I rode.

I'm thinking fuel delivery at this point. Removed tank and pump. Drained old gas. Tank was spotless. Checked all tank venting, cap and hoses. Pump sounded normal. No debris on suction screen. Inspected spark plugs, like new. No check engine light. Ran through all the diagnostic codes. No defects. Reassembled. New fuel. Checked fuel pressure, 43 psi. Tried to ride it again. Got 3 miles out. Engine got progressively worse and now breaking up even below 1/4 throttle. Turned around to get back and it died dead. No start. Waited 30 minutes. Bike started and I headed home. Kept running worse and worse in those 3 miles until it quit again 100 ft from my drive way. Dead sticked it in. Seems heat related.

So now I am thinking Crank sensor or Cam sensor. Even though I still have no codes. But I know they will check good when they are cool. I could just pull the trigger and get both but they are $75 ea. And those are just a guess. Searched for hours and do not see where anyone has either of these items as a confirmed failure.

Any thoughts greatly appreciated.

Bob

 

[SLK50]

I once had a bike ( not an FJR ) that had similar symptoms.

Chased a fuel delivery problem to no avail.

Turned out to be a bad coil that cut out once it got

above a certain temperature. Just sayin.

You may be right about the sensors but there should

be a way to verify their operation prior to replacement.

 

[MrZappo]

There were ZERO issues before you put it away? None? .

Very odd for a component to fail coincidentally like that. I'd always guess fuel delivery after a winter break.

How about the battery or battery connections. Have you 100 percent verified either of those?

 

[ionbeam]

S76, long time no see! Usually an abrupt cut-off is electrical. Your early Gen II is supposed to have had the ignition switch replaced and it's likely to be in the ground connector campaign. With such a significant event, if it was caused by a sensor I would expect a diAG code to be set. As previously mentioned, check your battery terminal connections. A bad Throttle Position Sensor can cause similar symptoms but usually it will cause running problems in a fairly narrow rpm band. Have the little rodents been snacking on your wiring harness in that dark, warm, dry basement?

When the engine shut off did the gauges remain functional and the dash lights stay on?

 

[Fred W]

He's alive!

(Good to see you, Bob!)

Another thing to rule out would be a bad TPS (Throttle Position Sensor). 2nd Gens were not particularly prone to bad TPSes like the 1st Gens were, but the TPS is a known weak point in any EFI system and can create running problems similar to what you describe. I had something similar on my Suzuki Vstrom that would result in an intermittent no-run situation. Since your symptoms are so severe, it should show up as some flaky readings in the diAG screen display of the sensor as you articulate the throttle.

edit - I see that Alan just said much the same thing. That's what I get for posting before reading all of the replies.

Good luck in your troubleshooting.

 

[S76]

Thanks to all for all of the ideas. Hi ionbeam and Fred, yes long time. Hardly rode at all the last couple of yrs but Mr. Bill has invited me to NAFTO so I gotta get this right.

Additional info:

Bike has the ign switch recall but is wired with a bypass relay as posted on this forum years ago.

I don"t have the factory Spider fix as I had this problem way before Yamaha got around to fixing it. All of the spiders have been modified but it was a home made fix that has worked for years.

I was able to read every digit of the TPS on the diag screen.

Bike sat for 5 months this winter and started perfect without any charger so battery and connectors is unlikely.

Bike has about 80K miles

No mice. Cats frequent the basement. I do have lots of claw punctures in my Russell seat though as they nap on the bike. GRRRR.

Today I will:

Check/Clean battery connections

Try to measure resistance of the crank sensor from the ECU and add heat

Try to measure the Cylinder Identification sensor resistance and add heat

Install spare ECU, just because I have one.

Inspect spiders and associated wires by the engine.

I wonder if it could be that ignition switch bypass relay? I could remove it and energize it and let it cook for a while to see if it opens. Although I should have seen the gauges going dead when it hiccups.

Well it's a dreary day today in CT so may as well puts with this in the basement.

Stay tuned.

 

[ionbeam]

TPS note -- I was never able to detect a problem with my TPS no matter what I did until I back-probed the connector, Velcroed my DMM to the handlebars and took it for a drive. The DMM clearly and immediately identified the TPS voltage drop-out at the same time as the engine misfire.

 

[kieefjr]

I'll assume you checked the air filter.

 

[S76]

IT'S ALIVE !!!!!!

Found the problem. It was, and is, embarrassing. I don't think I have ridden this bike 500 miles in the last 3 yrs. due to involvement with my sons race car and life in general. And I have not performed any maintenance either in that time frame except oil. So this morning I tore it all apart consuming large amounts of basement floor space for all the plastic etc. Then I spotted it. There is a aluminum cross brace on the frame that holds the back of the gas tank. When I installed the PC III years ago I used one of those attach bolts for the PC III ground wire. Well apparently the last time I had things apart I only hand tightened those bolts and now 3 yrs later it loosened up enough to make the ground connection intermittent. Tightened it up and reassembled everything and rode 40 miles.

PERFECT!

Thanks to all for your input and ideas.It is nice to know that you have some backup and unbiased thoughts when facing these type of problems that seem overwhelming. The forum is awesome.

Thanks

Bob

 

[ionbeam]

Glad you found it!

Glad it was a clear cut solution so there are no ongoing worries.

Glad it was so inexpensive to fix.

And so, it was electrical. Just not quite like we were expecting.

 

[FJRPittsburgh]

Woo hoo! It always feels good to resolve the problem. Good on ya!

 

[CCook82]

Good detective work. Pain but could have been never ending and you got familiar with it again.

 

[dcarver]

always nice to find the smoking gun!

 

[HotRodZilla]

Years ago, I installed a PC-III on my VTX. I started getting a weird stumble every now and then. Went through two services and the dealer couldn't repeat it. I. The way home from a trip, the bike barely ran. I got home, but had to trailer it to 5he dealer cuz it wouldn't run for more than 3 or 4 seconds.

They found the loose ground and all was well. Didn't even charge me to fix it. Since then, I've suggested checking the ground on every bike with problem with a PC-III installed, and that's never been it. Now when I forget, guess what...Oh, well, glad you got it!!

 

[S76]

So glad this is resolved. Now on to a valve check and installing the newer cam chain tensioner and we are good to go to NAFTO. Except, for a couple new Dunlops right before I leave. Now if I can keep Mr. Bill from wanting to camp on the way life will be good. Lol

 

[Fred W]

Bob,

On the new chain tensioner. look for a green dot.

There is no "Trade" in NAFO. Though you may start something new.

Dunlops are so last decade. All the cool kids run Michelins / Bridgestones in all sorts of combinations on their FJRs. Or Conti TKC80's in the dirt.

You will never catch Mr Bill not wanting to camp. Being a cheap prick, I kind'a like him for that. A good sleeping pad is what you really need.

Why aren't you riding to FODS with us on Memorial Day? Don't you still have that KLR?

PS - Say hi to Hope from Josie and me.

 

[Mihalis fjr]

Bob,
On the new chain tensioner. look for a green dot.

Fred,

As about the blue or green dots,only the CCT spare part that they send to US have these dots on and i don't know why..The CCT that they send to Europe they haven't any dot on blue or green...Really don't know why..?!Just today i was in the Yamaha dealer and i saw the last version CCT ''probably is the new version'':1 MC-12210-00and it hasn't any dot on green or blue.The dealer told me that he never saw a dot on blue or green..Very strange......

 

[RaYzerman19]

As long as you can identify it as the newest design version, that's really what counts. There are those with blue, no dot and green dot as supplied to the US too. As they run out, only the green dot ones will be left.

 

[gixxerjasen]

Awesome, gotta love inexpensive fixes, even if they are a little embarrassing. I was thinking rodents, which I'm quite glad for your sake that it wasn't. But it has happened before.