Gen II - Strange Cold Start Issue

I'm new to the board and have really enjoyed reading all the threads. I got my 2007 FJR second hand and can't keep my hands off it. Love that thing. Last week I rode 2,200 miles on my first sport touring trip from Houston to Big Bend and back - taking every curvy road I could find. In the Davis mountains I ran into some early morning trouble with the FJR - I tried to find the issue in another thread but didn't see anything like I experienced.

So, it was chilly in the Davis Mountains over night, getting into the lower 40's and would be about that when I went out to wipe down and warm up the bike while packing. The bike never had a problem starting nor idling. But when I tried to rev the engine it would often stall. I finessed the throttle to get the revs up to 3,000 - 4,000 to really get it warm, let off the throttle to idle and when I try to rev the engine again it would stall. I got the engine hot after some time and would try to do loops in the parking lot as if moving the bike would magically make a difference. I'd rev the engine pretty high by finessing the throttle to 5,000 rpm and feather the clutch in 1st gear and it would kill the engine like I was pulling an elephant. I then remembered something that a bike mechanic recently told me about ECU's being tempermental so I tried something for the hell of it. I turned the ignition all the way off and started the bike again after having the engine hot. Once restarted this way the FJR acted completely normal. The next three days I had similar issues and instead of fighting it I would heat up the engine at idle, shut the ignition all the way off and then restart and it would act normal.

Now that I'm back in Houston it's not so chilly the bike starts and runs from cold with no issues - I don't have to warm up and restart.

The altitude recall doesn't seem to fit the symptom here. Any suggestions?

Thanks!

FJR Freak

Did the auto choke work correctly when you started the bike cold? The FJR auto choke uses coolant controlled wax type choke to gradually bring the RPM back down as the coolant heats up the wax in the choke unit.

Are there any mods done to the bike, like a Power Commander and/or CO settings adjustments (assumes the Barbarian mod to the ECU plug) to help make the fueling richer?

Also, the fuel you had in the tank during that episode might have been dodgy.

It's an '07...check the VIN with your dealer and be sure the altitude sickness ECU swap was done.

HotRodZilla said:

It's an '07...check the VIN with your dealer and be sure the altitude sickness ECU swap was done.

Click to expand...

FJRFreak,

The Yamaha mothership (1-800-962-7926) can tell you if all recalls are done, for any year bike by VIN.

Cheers,

infrared

Thanks for the replies. I haven't made any mods myself yet but not sure about previous owner. It's time for some serious maintenance after my trip so I will start digging. I will also call dealer to see if it got a new ECU for the altitude recall.

I was wondering about the choke or crappy gas too but I'm skeptical of either being the issue. Because shutting ignition off after getting it hot seemed to reset something and it would act normal from that point on.

possible temp sensor problem, check the connection. Have you looked to see if a trouble code has come up?

I have an '07 too and it can be temperamental at times. First check for the ECU swap recall as mentioned. Second, if you haven't already done it, is the Barbarian Mod. Add 4 or 5 to each setting. Huge difference. Third is up the idle. Everyone says 1100 but mine doesn't do well there, kinda jumpy. I went to 1175. Perfect! Fourth is check your ground spiders!!! If the one up front, left, by the glovebox is wonky you'll get the symptoms you describe.

OK, thanks again for all the info folks. Update:

I got under the tank last night to check that the Black Widow grounding spider recall had been done - it was which made me feel instantly relieved after reading all the threads on this site.

Per infrared, I called the Yami mothership and they confirmed that the grounding harness work and the altitude fix had both been done to my bike. So, check and check.

I will now research running Diagnotics mode. The temp sensor, choke, and barbarian mod suggestions I will all look into as well. The bike idled fine so I don't see this as a low/flaky idle issue. Also, when I was warming up the bike at idle it seemed to know it warmed up because it transitioned from fast idle to slow idle after a few minutes as normal. This is just a real mystery why shutting the ignition off and turning it back on would seem to reboot the ECU to work right. Now that I'm back in balmy Houston I wonder if I can troubleshoot it well.

As rbentnail mentioned, check your (warm) idle speed. Very common to have issues with stalling if under 1100. I never felt the need to do the Barbarian mod but others have liked the difference in fuelling at low RPM.

Also be aware that just b/c the wiring harness recall was "done" that doesn't mean any parts were replaced or you won't have any problems ever again. The harness recall required an inspection be done. If any defects were found the harness is replaced. If not, then no parts are replaced. You have to delve deeper with Mammy Yammy to get something other than "the recall was done". Also, even with the recall, not all the ground spiders (8 of them) were addressed. We're still seeing problems with others.

Don't take anyone's word for it. Get in there and inspect your spiders yourself!!

It's difficult to troubleshoot if you are unable to repproduce the problem.

I pulled my hair out over a similar problem and the answer turned out to be a new battery even though the battery had always held a charge and never failed to start the bike. If the voltage drops below a certain level while starting it seems to confuse the ECU and a handful of throttle can straighten it out.

stealth1 said:

It's difficult to troubleshoot if you are unable to reproduce the problem.I pulled my hair out over a similar problem and the answer turned out to be a new battery even though the battery had always held a charge and never failed to start the bike. If the voltage drops below a certain level while starting it seems to confuse the ECU and a handful of throttle can straighten it out.

Click to expand...

This ^^^.... and I pulled my hair out too!

While not frequently reported, a few of us have been caught with marginal batteries and seen these symptoms. Bike appears to start fine and battery passes static voltage tests but low RPM throttle response and idle is erratic. My theory is with a marginal battery, during startup the voltage drops to a level that somehow corrupts something in the ECU. I'm guessing in your case the cold weather at Big Bend may have reduced battery capacity enough to trigger it. After you warmed up the bike and charged the battery a bit, then shut off ignition (clearing ECU) and restarted, the battery capacity was now enough to prevent problem.

You could check the sensors using the dash DIAG utility to confirm it's not a sensor gone bad, but they're pretty reliable (other than the TPS which there was a bad batch). If it's not happening now, wouldn't worry too much about it but as the battery ages I expect it will become more frequent.

I did check most of the grounding circuits and they looked good. I put some dielectric grease in them.

Since this is a used bike I'm not sure how old the battery might be. I like the theory of a weak battery as it would also be susceptible to the cold.

I think that the battery is suspect. Mine is an 08 and that was exactly the issue. Get a new yuasa or other high quality battery and let us know.

Best of luck.