Start trouble

Fred.ska

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Dec 15, 2018
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Hi all!

Just got my first S10 a few months and have run into my first problem. I would be very grateful for any advice.

A week ago I was changed one of the main lightbulbs and turned the bike off / on a couple of times to check that every was working.

The next day it would not start. The engine cranks but it doesn’t fire up. I’ve done the following.

Charged and measured the battery voltage
12.8v when bike is off
12.5v when ignition is on
10.5v when cranking

Changed air filter. Old one looked ok, but changed it anyway.

Changed all 4 spark plugs
Old ones weren’t great and probably were ok to change.

Unfortuneately, nothing has changed!

Any tips on next steps would be highly appreciated!
 

EricV

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It's not a big problem, just the classic hard start issue that sometimes occurs when you fire up the bike and shut it off w/o it fully warming up. This often happens when someone washes the bike, then fires it up to run it back into the garage. Checking new stuff has similar cycle sometimes.

If you don't tend to use the kill switch, this can occur w/o starting the bike too.

What happens is that the cold start enrichment cycle has dumped a bit more fuel into the cylinders and it's washed down the sides, taking the film of oil with it. This means low compression w/o the oil to seal the rings to the cylinder walls.

Pull the fuel injection fuse. Crank the bike until it starts to pop. Shut down, key off, kill switch to stop. Replace the EFI fuse. Key on, kill switch to run, crank the bike. If it doesn't fire right up, go to 3/4 throttle and keep cranking. It should catch and fire up before the battery runs down. If it doesn't, jump it with the car/truck and continue, but don't crank for more than 30 seconds at a time and let it cool a bit before trying again.

Once you get it started, let it warm up to at least 165 water temp before you shut it down. You should be fine after that. These bikes do not like to be fired up and then shut down w/o full warm up. End result is multiple cold start cycles and flooded engine.

Please report back after and tell us what you did and how that went. Also, take a few minutes to fill out your profile, at least with location. Just state or country if you prefer. City/state is nice. Or city/country for EU. It gives context to your posts and makes it easier to answer questions as well as understand your perspective.
 

Fred.ska

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Thanks for the detailed reply Eric. I’ve updated my profile with location.

Unfortunately, it didn’t get the bike to start. I’ll give it one more try tommorow, and if it still doesn’t fire I’ll just have to try to get it sent over to a mechanic.
 

EricV

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Considering the things you have done to the bike, are you sure you plugged the intake air temp sensor back in when you re-installed the air box? Throttle side, two wire plug. The sensor fits into a rubber grommet in the side of the air box. it gets forgotten sometimes.
 

EricV

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I would also consider jumping it. At a certain voltage the ECU won't fire the injectors. I can't remember what that is, but 11v is stuck in my head. If that's right, your battery might not be holding up under load and the voltage may be too low when cranking to allow the ECU to fire the fuel injectors.

If you end up needing to replace the battery, replace it with a YTZ14S. It's the same physical size, but heavier with more CCAs.
 

Dogdaze

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All what Eric mentioned, if you raised the tank, check to see if the breather hoses from the tank are bent/ crimped, this has been a known cause too.
 

backfill

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I have had this issue and for the same reason. I started the bike and shut it off without letting it warm up. I tried multiple times to start the bike but no luck. My brother is a GM mechanic and he suggested holding the throttle wide open while holding the starter. It cranked over a few times then fired right up. I am more careful now to make sure the bike warms up before shutting it off and have not had the issue since.
 

squarebore

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I have had this issue and for the same reason. I started the bike and shut it off without letting it warm up. I tried multiple times to start the bike but no luck. My brother is a GM mechanic and he suggested holding the throttle wide open while holding the starter. It cranked over a few times then fired right up. I am more careful now to make sure the bike warms up before shutting it off and have not had the issue since.
When it wont start that is the first thing to try. Happened half a dozen times on my gen 1 and WOT got it going each time. Never had to pull the FI fuse.

Sent from my SM-T580 using Tapatalk
 

GearheadGrrrl

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Happened to me once in 50k miles on my '13, gave it WOF while cranking and after a couple seconds it started. Lately I've noticed some slow starts when warm so I've been experimenting a bit- left it out overnight and it started right up at 20-30 F but then was slow starting after I shut it off when warm. Could be the wiring harness problems that led to the recall, could be that the S10's computer has trouble adapting to 40 F temps and a warm engine. Or could be that I need to quit being a cheapskate and replace the original battery...
 

Paqard

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Washington State
Hi all!



Charged and measured the battery voltage
12.8v when bike is off
12.5v when ignition is on
10.5v when cranking

You've done all the trouble shooting you need right there. It isn't starting with 10.5v when cranking. I assume the bike was not running with the lights on when you tested the new bulb installation. It brought the already marginal battery down too low to start the bike. Recharge the battery , replace the battery or jump start it. NOTE : DO NOT start the other vehicle if it is a car as the amps produced and delivered from it will potentially fry things! It'll be too much for your "little" bike battery. Just hook up the jumper cables and start the bike. Then disconnect the cables.
 

richarddacat

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I’ll remember these tips because I just experienced a hard start.
I’ve had my ECU out for a flash (thanks Anthony) and had the battery disconnected until it got back, about 7days. I reinstalled it and put the battery charger on it overnight.

Right after I plugged the ECU back in I did start it, no problem then but the next day it cranked and cranked, almost like no fuel. Finally started, rode two hours without stopping, got home shut off and restarted without issue.
I don’t remember the fuel pump kicking in when I turned on the key......? I’ll recheck.
 

EricV

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Happened to me once in 50k miles on my '13, gave it WOF while cranking and after a couple seconds it started. Lately I've noticed some slow starts when warm so I've been experimenting a bit- left it out overnight and it started right up at 20-30 F but then was slow starting after I shut it off when warm. Could be the wiring harness problems that led to the recall, could be that the S10's computer has trouble adapting to 40 F temps and a warm engine. Or could be that I need to quit being a cheapskate and replace the original battery...
That's interesting behavior. I wonder if the artificially warm air box Vs the much colder air coming in had some impact?

Might be worth double checking grounds, just for the heck of it. A little corrosion makes a big difference, but I would expect it to be uniform, regardless of cold or warm start. Hmmm.
 

EricV

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I’ll remember these tips because I just experienced a hard start.
I’ve had my ECU out for a flash (thanks Anthony) and had the battery disconnected until it got back, about 7days. I reinstalled it and put the battery charger on it overnight.

Right after I plugged the ECU back in I did start it, no problem then but the next day it cranked and cranked, almost like no fuel. Finally started, rode two hours without stopping, got home shut off and restarted without issue.
I don’t remember the fuel pump kicking in when I turned on the key......? I’ll recheck.
I'm thinking you didn't let it warm up when you started it after plugging in the ECU?
 

richarddacat

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I'm thinking you didn't let it warm up when you started it after plugging in the ECU?
Hopefully that was it. How does that have an effect on it?
I wanted to make sure it started before I buttoned everything up, pretty much on and off.
 

EricV

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Hopefully that was it. How does that have an effect on it?
I wanted to make sure it started before I buttoned everything up, pretty much on and off.
See earlier posts. Cold start routine causes a rich condition, etc. Flooded, low compression, no start.
 

Fred.ska

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Well guess who just got his S10 running again!

I can’t tell you exactly what did it in the end as I combined the advice of pulling/replacing the fuel injection system fuse and jumping with a 1200 amp jump starter.

What I can tell you is the following

1) I’m very grateful to those that responded to my thread post and got me going again. Thank you very much!

2) I’m never shutting down the bike before it’s properly warm again!

3) I’m buying a new battery.


Now that the bike is back to life I have a bunch of questions/observations

When I removed the fuel system fuse and cranked the bike I was able to get it to fire while holding the ignition button but after I replaced the fuse it didn’t fire the first few times. My questions are

1) Were the cylinders still getting fuel despite the fuse being removed?
2) Anyway to make sense of that observation or was it just coincidence?

What is the consensus with regard to use of ignition key and kill switch for starting and stopping the S10 and what is the rationale behind it?

Eric, you recommended the YTZ14S. Do you have a manufacturer you would recommend?

Thanks again all!
 

EricV

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Hi Fred - Glad you got the bike started! Well done. And thanks for reporting back.

No new fuel was getting to the cylinders with the fuse out. You were burning the residual fuel from being flooded. Once you got enough air in to offset the excess fuel and the air/fuel ratio got to where it would pop and trie to fire up, it should have been good to go for a fresh start with normal conditions.

After you put the fuse back in, it may simply be that the system needed to prime a bit before you got normal fuel flow from the injectors. Normal start routine is to turn the key on, kill switch to run, wait for the gauges to finish their sweep and by that time the fuel pump should have come on and pressurized the system, then shut off, then crank the bike until it starts. (which normally doesn't take much)

I prefer the Yuasa batteries. Others have had good luck with different brands. Odyssey has also been good for me in the past. They like to market as a dry cell so they can be shipped easier, but they are really an AGM just like the other brands. You can do a search on Battery and see what pops up. There have been some good reports with lesser known brands. Any YTZ14S should crank faster than the 12 did and you should notice the difference in starting.
 

NewAdvRider

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My 2017 wouldnt start this morning.

Had to go to work so I took the cage. I'll probably be able to skip out a bit early today and mess with it. I washed it saturday, sounds a lot like Eric V's description.

Rather than having to take out the FI fuse, etc, isn't the flooded situation from too many cold starts something that one that would 'fix' itself if I let the bike for several hours, like it's doing now?

Or am I just hoping very strongly that I will get home and it will just start?
 
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