2008 ECU swap question

[gumba]

I did Sat.morning at the 013 SW-FOG and every Gen2 owner I talked to had experienced the Cold Start Syndrome. I threw out the ECU swap thing and then thought, on my way home, where did I get that b.s.. I had fixed the problem with a better battery. My theory is that the Gen2 ECU does not like a week battery on a cold restart. I had the problem with a battery that would turn over and start, but in doing so it threw a voltage at the ECU that put it in a funk. This funk was repeatable every time I rode up in altitude on a cold morning. A new GOOD battery fixed the problem. side note: a guy at the FOG with 5 years on a battery was ready to send his scooter to the crusher with this problem.

 

[Panman]

I rode my 08 in the mountains, up to 6000 ft in April and May, when it was so cold that there were snow fluries, and never had a restart problem.

Our Mountains are lower than their flat lands??

 

[MCRIDER007]

I rode my 08 in the mountains, up to 6000 ft in April and May, when it was so cold that there were snow fluries, and never had a restart problem.

Our Mountains are lower than their flat lands??

They can be......that's why I included the actual elevations.

 

[HotRodZilla]

Yes, your mountains are lower than our flatlands. My driveway is at 5110 feet. I have an '07 and have NEVER experienced this problem. I was at SW-FOG in Salida in '13 and didn't have it either. Ride to 11,000+ feet on a regular basis and never had an issue...Even before I had the ECU recall performed. The only reason I did that was because my service manager at the time did it during an oil change and my bike was less than a year old.

There's something going on with Stealth's '08 other than the ECU, unless his is just bad.

 

[Ignacio]

There's something going on with Stealth's '08 other than the ECU, unless his is just bad.

I agree with my atmospherically-pressure-challenged friend. There's likely something else here before jumping to ECU swap conclusions. I don't know what it is and been throwing some spaghetti to the wall about seasonal fuel that may not be it either, but I'd urge the OP to go through this from scratch.

Their are some great diagnosticians that could weigh in if you'd be willing to walk through your issues closer to the beginning.

 

[stealth1]

I rode my 08 in the mountains, up to 6000 ft in April and May, when it was so cold that there were snow fluries, and never had a restart problem.

Our Mountains are lower than their flat lands??

They can be......that's why I included the actual elevations.

My house is at 5700' and we are down in the valley.

 

[stealth1]

I did Sat.morning at the 013 SW-FOG and every Gen2 owner I talked to had experienced the Cold Start Syndrome. I threw out the ECU swap thing and then thought, on my way home, where did I get that b.s.. I had fixed the problem with a better battery. My theory is that the Gen2 ECU does not like a week battery on a cold restart. I had the problem with a battery that would turn over and start, but in doing so it threw a voltage at the ECU that put it in a funk. This funk was repeatable every time I rode up in altitude on a cold morning. A new GOOD battery fixed the problem. side note: a guy at the FOG with 5 years on a battery was ready to send his scooter to the crusher with this problem.

Thanks. That was probably me. I might give the battery a try. Mine has some age on it, but seems OK otherwise. Lots cheaper than an ECU for sure.

 

[Denver_FJR]

I did Sat.morning at the 013 SW-FOG and every Gen2 owner I talked to had experienced the Cold Start Syndrome. I threw out the ECU swap thing and then thought, on my way home, where did I get that b.s.. I had fixed the problem with a better battery. My theory is that the Gen2 ECU does not like a week battery on a cold restart. I had the problem with a battery that would turn over and start, but in doing so it threw a voltage at the ECU that put it in a funk. This funk was repeatable every time I rode up in altitude on a cold morning. A new GOOD battery fixed the problem. side note: a guy at the FOG with 5 years on a battery was ready to send his scooter to the crusher with this problem.

Your scenario sounds almost exactly the same as problems I had with my '07. In frustration I swapped to an '08 ECU which made no change. I later discovered the voltage during startup was dropping to around 8.5 volts. I have since replaced battery and problem has not returned (and yeah, terminals on old battery were cleaned multiple times, always on tender, yadda, yadda).

In my case the problem was always present upon start and not related to any change in elevation, but then I live at 5200'. My theory is also the drop in voltage during startup corrupts some sensor reading within ECU. ECU voltage funk!

 

[stealth1]

I did Sat.morning at the 013 SW-FOG and every Gen2 owner I talked to had experienced the Cold Start Syndrome. I threw out the ECU swap thing and then thought, on my way home, where did I get that b.s.. I had fixed the problem with a better battery. My theory is that the Gen2 ECU does not like a week battery on a cold restart. I had the problem with a battery that would turn over and start, but in doing so it threw a voltage at the ECU that put it in a funk. This funk was repeatable every time I rode up in altitude on a cold morning. A new GOOD battery fixed the problem. side note: a guy at the FOG with 5 years on a battery was ready to send his scooter to the crusher with this problem.

Your scenario sounds almost exactly the same as problems I had with my '07. In frustration I swapped to an '08 ECU which made no change. I later discovered the voltage during startup was dropping to around 8.5 volts. I have since replaced battery and problem has not returned (and yeah, terminals on old battery were cleaned multiple times, always on tender, yadda, yadda).

In my case the problem was always present upon start and not related to any change in elevation, but then I live at 5200'. My theory is also the drop in voltage during startup corrupts some sensor reading within ECU. ECU voltage funk!

Thanks for the input.

I guess my primitive mind was just having a hard time grasping the bad battery scenario Since in every other condition it seems to work fine.

I guess with today's modern electronics There is more to batteries than just good and bad. Some definite gray areas.

Especially thanks for the info about changing your ECU with no improvement. Glad I didn't go down that expensive road yet.

I would order a new battery today except for the fact that we are awaiting news from my daughter who is expected to deliver our 3rd grandchild any day now.

When we get the call we are headed for Las Cruces for a while.

Editing to add that this forum is definitely a great resource for information,

Especially for those of us who live in relatively remote areas.

 

[ionbeam]

...I later discovered the voltage during startup was dropping to around 8.5 volts. I have since replaced battery and problem has not returned...

8.5 volts is getting down towards the minimum voltage for the coils to produce an energetic spark at engine cranking speed.

The ECU monitors electrical system voltage at the fuel injectors and the voltage can be read via diAG so you can see what the ECU is reading.

 

[Denver_FJR]

8.5 volts is getting down towards the minimum voltage for the coils to produce an energetic spark at engine cranking speed.
The ECU monitors electrical system voltage at the fuel injectors and the voltage can be read via diAG so you can see what the ECU is reading.

I knew I could get voltage through diAG and had checked it many times while engine off, but I can't recall that I ever monitored while engaging the starter. It was also before I learned (via an ionbeam post thank you very much) that below 9 volts was likely in the trouble zone, so even if I had looked it wouldn't have thrown a flag up.

At that time the engine seemed to turn over fast, start quickly and I never had the typical low voltage clock/trip meter reset signs so it threw me for a while.

 

[stealth1]

Well I guess it's time for an update.

Since my last post in this thread I have spent a week in Las Cruces where I now have a new grandson born on the 17th of October. Mother and baby are both doing fine.

Now confession time.

I am an ignorant Luddite.

I assumed that since my battery always held a charge and always started the bike that it was fine. Evidently not so in this modern high tech world.

My new battery arrived yesterday afternoon. I charged it and installed it last night.

I took a 76 mile ride this afternoon up to Cedar Breaks (10,000') and Duck Creek (about 9000'). Temps in low 50's both places.

At both locations when I tried to restart the bike It fired instantly, idled smoothly, and took gas without a hiccup. Could not have asked for better fueling or performance.

Anybody want to buy a slightly used (6 yr old) battery that will start your bike and hold a charge?

 

[petey]

Good to know....glad you have it sorted....you'll sleep better tonight...

 

[Spud]

I too had a couple of weird starting experiences that scared the crap out of me because I was alone a LONG ways from anywhere... High altitude and cold. Once at Bryce Canyon in March or April, 9000 feet and high 20's, bike damn near wouldn't start, I roll started it down the road and it ran fine once going. Happened again at Old Faithful on an early spring ride. Wouldn't run right for a bit.

Replaced battery--good to go. No problems since in similar conditions. For around $100 a fresh battery is a great investment, especially when you need to cold crank in the high Rockies after freezing nights... Not that it's the answer to everything, but it is to a lot of things on this bike it would seem.

 

[Denver_FJR]

... It fired instantly, idled smoothly, and took gas without a hiccup. Could not have asked for better fueling or performance.

Right on! And cheaper then a replacement ECU.

 

[stealth1]

... It fired instantly, idled smoothly, and took gas without a hiccup. Could not have asked for better fueling or performance.

Right on! And cheaper then a replacement ECU.

And thanks again to all the forum members who helped point me in the right direction.

And I did sleep better last night.

 

[richsp51]

Nice post, thanks for the follow up as this is interesting info on one of the possible effects of a weak battery. Also, congratulations on the new grandson!