Suddenly won't fire 😩

Randall-in-Mpls

Randall-in-Mpls

Yearling Deauville owner!
Joined
Jan 19, 2023
Messages
110
Location
St Anthony, MN
Bike
2010 NT700V, 1978 CX500
Looking toward the great weather this week, I uncovered the NT Sunday night. Despite being asleep since early December, it started with no hesitation.
Monday morning, I rolled it out for my commute to the office. It would crank, but not fire. Ran the battery down with repeated attempts. It was on the 2A charger overnight, but I haven't tried again.
Someone, please point out something stupid I've overlooked!
I can hear the fuel pump coming on with the switch. I can't imagine both plugs fouling at the same time, and one would allow it to run, if poorly.
I can't think what would have changed to cause this between Sunday night and Monday morning. Any insights before I dig out the service manual tonight?
Thanks.
 
Obvious ones are kill switch and not in gear with side stand down, but presume you have checked those! Crankshaft position sensors can fail, but usually give problems when warm before failing. There is fuel in the tank of course..... Poorly batteries (how old is it?) can also give the same issue, otherwise it could be dodgy electrical connection to the ECU or in the starter switch itself. Will probably start fine now.....!!
 
It turns over, so the kill switch and neutral/clutch lockout won't be suspects. I have considered the sidestand switch.
Monday morning, I was sitting on it in neutral with all stands up. Monday evening in neutral on the center stand, which usually works. A short in the side stand circuit isn't unheard of. Is that a known gremlin on this model?
I'll try to pull a plug tonight. That should show me whether it's fuel or spark that's missing.
Thanks.
 
The Side Stand switch connects to ground. So if either side of the switch "shorted to ground" this wouldn't prevent the starter motor from turning and the engine starting.

Add some fresh fuel if it's been 3 months. Charge it. Try again.

Just past experience but not really able to explain it... On a few rare (2 or 3 times) my NT won't start 1st try has been when it was either 1) last started and not warmed up fully OR 2) I may have accidentally had throttle open with a fat hand or glove. Either way, it either started by cranking it longer or I recall it once needing the throttle open some while cranking and it started. Not sure, but it acted flooded but eventually started and was fine after that.
 
The crank position sensor is a possibility, but yours doesn't match the usual symptoms of intermittently failing while hot. So that doesn't seem too likely.
It has been sitting a while so maybe some electrical connection issue??

Arknt
 
dnktng said:
The Side Stand switch connects to ground. So if either side of the switch "shorted to ground" this wouldn't prevent the starter motor from turning and the engine starting.
Click to expand...
No problem getting the starter to turn. Just no combustion.

Add some fresh fuel if it's been 3 months. Charge it. Try again.
Click to expand...
E0 in the tank, which doesn't go stale like the corn-beer garbage. It started happily on the old gas Sunday evening.

On a few rare (2 or 3 times) my NT won't start 1st try has been when it was either 1) last started and not warmed up fully OR 2) I may have accidentally had throttle open with a fat hand or glove. Either way, it either started by cranking it longer or I recall it once needing the throttle open some while cranking and it started. Not sure, but it acted flooded but eventually started and was fine after that.
Click to expand...
I tried a little throttle, as my older machines like on a cold start, but no change. FI shouldn't need that, anyway.
Cranked until the battery ran down. After a full charge, it spins eagerly, but still no combustion.

The only thing I changed was to remove the rear case and tighten the two rear mounting bolts on the Givi rack. Unless there's a kill circuit wire in the tail that got pinched, I can't see how that's a factor. I'm guessing the kill switch is power on for ignition, unlike my old CX which grounds the signal to kill it, so a pinched wire should blow a fuse, rather than merely inhibit spark.

I grabbed my shop manual from the garage. I'll go through it tonight to see what plastic I need to remove to learn anything.

Thanks.
 
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After fixing the mirror on my truck, I didn't get too much into the NT. I did confirm the sidestand switch is operating properly. Next chance will be Thursday evening when I'll pull the forward plug to look for spark and sniff for fuel.
 
Will a basic automotive ODB2 scanner work with this, or would l need something special?
I'm finding lots of gadgets in the wiring diagram that could be behind this. Regardless of no fuel vs no spark, a scan might be the best place to start.
 
OB2 scanner doesn't work. If any codes, they flash a two digit flash of long and short with the engine light flashing.

Have the spark plug cap recall been done?
 
I haven't heard of that. What would indicate it's been done?
Would both caps fail in the same moment?
 
OBD2 don't work.

This this the normal sequence. Turn the key on. Listen for fuel pump. Note that MIL comes on for short time and then goes off. If it stays on, read it per below thread.

If everything seems normal in the above, crank the starter for >10 seconds to see if a MIL does come on, then read it per the below thread.

[How To] - Read & Reset MIL | How To's

Read & Reset Maintenance Indicating Light (MIL), aka Check Engine Light (CEL) Before STARTING the NT, verify the MIL light has cleared after the short self-check. If the MIL stays on after the short self check, don't start the NT or cycle the ignition switch to clear the MIL. If the MIL is...
www.nt-owners.org

If you have a Honda Shop Manual your troubleshooting should start with chapter 6. Chapters 20 and 21 are valuable and you may end up there too.
 
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Spark plug cap recall, might find out by previous owner or VIN# at dealer to run it
 
Randall-in-Mpls said:
Looking toward the great weather this week, I uncovered the NT Sunday night. Despite being asleep since early December, it started with no hesitation.
Monday morning, I rolled it out for my commute to the office. It would crank, but not fire.
Click to expand...
Possible rodent infestation? They love working their little teeth on those cables...
(Had a similar symptom after doing service on my GF's NT700VA due to missing to attach aft flap-position sensor connector upon re-attaching the throttle bodies...
Won't throw a fault code, cranks but not firing...)
 
dnktng said:
OBD2 don't work.

This this the normal sequence. Turn the key on. Listen for fuel pump. Note that MIL comes on for short time and then goes off. If it stays on, read it per below thread.

If everything seems normal in the above, crank the starter for >10 seconds to see if a MIL does come on, then read it per the below thread.

[How To] - Read & Reset MIL | How To's

Read & Reset Maintenance Indicating Light (MIL), aka Check Engine Light (CEL) Before STARTING the NT, verify the MIL light has cleared after the short self-check. If the MIL stays on after the short self check, don't start the NT or cycle the ignition switch to clear the MIL. If the MIL is...
www.nt-owners.org

If you have a Honda Shop Manual your troubleshooting should start with chapter 6. Chapters 20 and 21 are valuable and you may end up there too.
Click to expand...

Even if the MIL isn't on, use this procedure to check if any fault codes are present in the ECU. If there are, you at least have a clue where to begin your diagnosis.

Mike
 
dnktng said:
OBD2 don't work.

This this the normal sequence. Turn the key on. Listen for fuel pump. Note that MIL comes on for short time and then goes off. If it stays on, read it per below thread.

If everything seems normal in the above, crank the starter for >10 seconds to see if a MIL does come on, then read it per the below thread.

[How To] - Read & Reset MIL | How To's

Read & Reset Maintenance Indicating Light (MIL), aka Check Engine Light (CEL) Before STARTING the NT, verify the MIL light has cleared after the short self-check. If the MIL stays on after the short self check, don't start the NT or cycle the ignition switch to clear the MIL. If the MIL is...
www.nt-owners.org

If you have a Honda Shop Manual your troubleshooting should start with chapter 6. Chapters 20 and 21 are valuable and you may end up there too.
Click to expand...
Thanks for that. I'll try it next chance I get.
 
ST1100Y said:
Possible rodent infestation? They love working their little teeth on those cables...
(Had a similar symptom after doing service on my GF's NT700VA due to missing to attach aft flap-position sensor connector upon re-attaching the throttle bodies...
Won't throw a fault code, cranks but not firing...)
Click to expand...
I haven't seen any evidence, but I'll look closer. Thanks.
 
Before you tear into it, see if it starts after a day or two of rest. If it doesn't fire immediately, open the throttle all the way while cranking just like the engine is flooded, it may have been flooded. It is hard to flood a FI engine, but under the right circumstance, it can be done.

Mike
 
No MIL code, at power on or after a long crank.
dnktng said:
Either way, it either started by cranking it longer or I recall it once needing the throttle open some while cranking and it started. Not sure, but it acted flooded but eventually started and was fine after that.
Click to expand...
mikesim said:
If it doesn't fire immediately, open the throttle all the way while cranking just like the engine is flooded, it may have been flooded.
Click to expand...
Following this bit of advice, though, I did get it to start and idle. Unless the forecast is wet, I'll ride it tomorrow.
Thanks, all, for your help and advice.
 
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