Engine Trouble - intermittently won't start! Any ideas on what to look for?

[Snowbelt Spyder]

All fuel injected engines can become flooded. It just doesn’t happen that often. That’s why the ECM is programmed with an “engine clear mode”. BRP/BOSCH calls it “drowned engine mode”, or something like that. The 998 was especially sensitive to that for some reason. Probably why you heard it trying to start. It might start after sitting all night. If not, go through all of your start steps, hold the throttle wide open first, then hit the start button for about 10 seconds. Fuel is cutoff when doing this allowing the engine to clear. Then release the throttle grip back to the normal position and try the start again. Repeat once more if necessary. Let the starter cool a bit before more repeated attempts. Many 998 owners have needed to do this at some point. About once a year for my old 2012, especially after a stall or aborted start.

 

[Roadsterryder]

How about the Crank Position Sensor failing intermittently?

How would I know? She started up fine today and I drove another 25 miles with 2 stops and every time she started up again…

All fuel injected engines can become flooded. It just doesn’t happen that often. That’s why the ECM is programmed with an “engine clear mode”. BRP/BOSCH calls it “drowned engine mode”, or something like that. The 998 was especially sensitive to that for some reason. Probably why you heard it trying to start. It might start after sitting all night. If not, go through all of your start steps, hold the throttle wide open first, then hit the start button for about 10 seconds. Fuel is cutoff when doing this allowing the engine to clear. Then release the throttle grip back to the normal position and try the start again. Repeat once more if necessary. Let the starter cool a bit before more repeated attempts. Many 998 owners have needed to do this at some point. About once a year for my old 2012, especially after a stall or aborted start.

She started up this morning without any hesitation. Drove 25 miles with 2 stops. First stop after 1 mile to top of the tank and added some more Heet Injector cleaner and water remover. She started right up and I continued my trip to Home Depot. When I tried to start the engine again about 15 minutes later she did not start right away. It‘s like she tried to start but died again. Turned off the ignition right away, waited about a half of a minute, tried again, and she started right up…

 

[mecsw500]

If the engine cranks and whilst it is cranking you should see the rev counter respond. If the rev counter doesn't move then there is a possible crank sensor problem. They are notoriously finicky sensors that often get killed by heat and then become intermittent depending upon heat cycles and drive you to the point of distraction.

You can buy an aftermarket one for well under $40 off of Amazon. You don't have to tear the engine apart to get to it and change it.

If it happens more often after the engine is hot, that's when crank position sensors love to die. I've had them fail on many cars and motorcycles and spent hours chasing my tail on other miscellaneous causes. I hate them with a passion, whether they are optical or hall effect technology. They often fail to trigger error codes which makes me dislike the things further.

They should also not be short circuit or open circuit measured across their terminals when unplugged from the harness, using a ohm meter setting on your multimeter. Different types have different resistance but most should not be open or closed circuit. I'd start with cleaning up the harness connections with contact cleaner.

Frankly, after all the fuss you have had, you might want to just change it with a cheap aftermarket one. From what I was able to look up the BRP part number is 420966570 and fits a variety of BRP vehicles but you might want to check that. They are on Amazon and fit like 200 different Can Am vehicles. If it isn't the problem then you can always return it.

I found them on Amazon for pretty cheap. You might want the OEM part from BRP if it fixes the issue for long term piece of mind, but I suspect the $120 BRP part is a $30 cheapo part anyways.

 

[Snowbelt Spyder]

How would I know? She started up fine today and I drove another 25 miles with 2 stops and every time she started up again…



She started up this morning without any hesitation. Drove 25 miles with 2 stops. First stop after 1 mile to top of the tank and added some more Heet Injector cleaner and water remover. She started right up and I continued my trip to Home Depot. When I tried to start the engine again about 15 minutes later she did not start right away. It‘s like she tried to start but died again. Turned off the ignition right away, waited about a half of a minute, tried again, and she started right up…

Yeah, it's frustrating. But history has shown that every 998, unless it was a garage queen, transitions through the same series of issues that need corrected at some point. That's why EVERYBODY with any experience knew that your MAP sensor vacuum hoses would be cracked. They all did it. That's why I pointed out to you the WOT engine clearing steps above. Also, if you haven't already down so, I strongly urge you to do a canisterectomy ASAP. Use the forum search function for instructions. I wouldn't get too concerned about this or that hypothetical failure, until you've proactively taken care of the things that you know will be an issue down the road. The better news is that you have a SM5 and don't have to worry abut your shift linkage falling off. Keep at it. Good Luck.

 

[Roadsterryder]

Here we go again.
Started up this morning no problem, drove to the doctors office and when I got back out 50 minutes later she didn’t start… grrrr.
I should say it tried to start but then died. Holding the throttle wide open and for 10 seconds and then tried again… nothing. I will wait another 15 minutes and try again. When I get back home I will disconnect the canister as suggested.

 

[Snowbelt Spyder]

Well, it’s more than JUST disconnecting the canister. Must plug the line leading up to the purge valve, too. Follow the steps that you’ll find on the forum. BajaRon has a good write up from back when.

 

[Roadsterryder]

Well, it’s more than JUST disconnecting the canister. Must plug the line leading up to the purge valve, too. Follow the steps that you’ll find on the forum. BajaRon has a good write up from back when.

I will check into it. Right now waiting for the tow truck.

 

[Roadsterryder]

Well, it’s more than JUST disconnecting the canister. Must plug the line leading up to the purge valve, too. Follow the steps that you’ll find on the forum. BajaRon has a good write up from back when.

I just read the write up from BajaRon and also watched a YouTube video about it. It looks pretty much straight forward to seal the line #19 and reroute the line from the tank. Still waiting for the tow truck so I had plenty of time… lol.

 

[Snowbelt Spyder]

I just read the write up from BajaRon and also watched a YouTube video about it. It looks pretty much straight forward to seal the line #19 and reroute the line from the tank. Still waiting for the tow truck so I had plenty of time… lol.

Hot start/heat soak start issues is what that would correct, along with random stalling at idle. Hoping that helps. Keep at it. You’ll get this worked out at some point.

 

[Roadsterryder]

Just 5 minutes before the tow truck arrived I tried to start the engine again and it started. Cancelled the tow truck and drove back home without issues.
Got the canister out, plugged the hose to the purge valve #19 and now trying to find a good place for the filter that goes on the line from the tank. I’m assuming it should be located higher than the top of the tank.

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[Snowbelt Spyder]

Just 5 minutes before the tow truck arrived I tried to start the engine again and it started. Cancelled the tow truck and drove back home without issues.
Got the canister out, plugged the hose to the purge valve #19 and now trying to find a good place for the filter that goes on the line from the tank. I’m assuming it should be located higher than the top of the tank.

View attachment 255527 - View attachment 255528

Not really. Mine wasn’t. You don’t need to try to prevent a siphon or anything like that. The tank will still breath in and out just like always, but now through the modified vent line directly to atmosphere. The filter keeps the incoming air clean, plus it makes for a convenient coupling to connect the two hoses together. FYI, The tank has a roll-over valve at the top vent of the tank. It’s the high point in the system. You don’t need to go higher. It's probably too late now, you've already done it.

BUT, you need to keep the purge valve connected to its electrical connector. It’s unplugged in your picture. Otherwise you get a failure code for that. The computer never knows that the line is plugged, but it knows if the valve is unplugged. The whole idea of doing this mod is to eliminate the vacuum / air leak that is inherent in the operation of the system. If the purge valve is leaking when shutdown, then fuel vapors from the tank saturate the intake manifold, displacing the air and preventing a hot or heat soak start. Standard symptom on pretty much any vehicle. I feel good that this makes a difference for you. (a statement that will probably come back to bite me)

 

[mecsw500]

Going back to the crank sensor. When it doesn't start, as it's cranking does the rev count move or not? If it doesn't, then I'd look at the crank sensor, they often fail when hot as their failure mode and start working again as they cool off.

 

[Roadsterryder]

Going back to the crank sensor. When it doesn't start, as it's cranking does the rev count move or not? If it doesn't, then I'd look at the crank sensor, they often fail when hot as their failure mode and start working again as they cool off.

I never paid attention to the rev count but I will when it happens again.
Right now I did the canisterectomy and it is getting late here in Michigan.

 

[mecsw500]

Yes, if the crank sensor is working, just turning the engine over will give you enough revs to make the tachometer needle move a bit. If the crank sensor is playing up when it's not starting, then the tachometer needle won't move at all. You can get them cheap off Amazon for like $40.

 

[Roadsterryder]

Yes, if the crank sensor is working, just turning the engine over will give you enough revs to make the tachometer needle move a bit. If the crank sensor is playing up when it's not starting, then the tachometer needle won't move at all. You can get them cheap off Amazon for like $40.

I will check. But, where is the crank sensor located?? I have no idea.

 

[Roadsterryder]

Not really. Mine wasn’t. You don’t need to try to prevent a siphon or anything like that. The tank will still breath in and out just like always, but now through the modified vent line directly to atmosphere. The filter keeps the incoming air clean, plus it makes for a convenient coupling to connect the two hoses together. FYI, The tank has a roll-over valve at the top vent of the tank. It’s the high point in the system. You don’t need to go higher. It's probably too late now, you've already done it.

BUT, you need to keep the purge valve connected to its electrical connector. It’s unplugged in your picture. Otherwise you get a failure code for that. The computer never knows that the line is plugged, but it knows if the valve is unplugged. The whole idea of doing this mod is to eliminate the vacuum / air leak that is inherent in the operation of the system. If the purge valve is leaking when shutdown, then fuel vapors from the tank saturate the intake manifold, displacing the air and preventing a hot or heat soak start. Standard symptom on pretty much any vehicle. I feel good that this makes a difference for you. (a statement that will probably come back to bite me)

I did plug in the valve. I was planning on taking more pictures but I got so wound up that I totally forgot. The existing vent hose was long enough to plug in the filter and attached it next to the air box and I added hose to the other side and routed it to the front near the steering box. That should work. Before I plugged in the filter and before I secured everything with ty wraps I started the engine and she started right up. Then after I finished everything and reinstalled the cover I tried to start the engine again and she acted just like before… didn’t start. Checked for code…nothing. Opened the throttle all the way and pushed the starter for about 7 seconds. Tried again… nothing. Waited 2 minutes and she started right up. Drove the Spyder for about 7 miles with no problem. Backed into the garage and turned the engine off. Waited about 10 seconds and she started right up again. I am done for tonight and I will see tomorrow. Thanks for all your help. It‘s greatly appreciated.

 

[mecsw500]

I will check. But, where is the crank sensor located?? I have no idea.

Down on the left side of the engine by the magneto. It's a black plastic sensor with one bolt and a two wire cable about a foot long, or less. It's easy to change once you have the Tupperware off. Basically as the magneto spins it triggers the sensor every revolution. This indicates to the ECU that when you are thumbing the starter that the crank is actually turning.

The sensor tells the ECM the crank is turning which drives the engine tachometer. If the sensor is not telling the ECM anything, the tachometer won't flicker on startup, there will be no fuel injected and no spark. This stops the injectors continually pumping fuel into a stationary engine leading eventually to a potential hydraulic lock or a fire blowing back into the air filter.

They are very cheaply made yet proper function is essential for the engine to start and run. They love to go intermittent based on temperature and drive owners to the point of insanity.

I'm not saying this is your problem, but for $40 off Amazon for a cheap replacement, the 20 minutes it takes to change it to eliminate that as a possibility, would be where I would go next. You have covered just about every other thing I can think of, all the obvious things, I just don't really know what to suggest next other than an exorcism or a Buddhist blessing ceremony.

 

[Roadsterryder]

Down on the left side of the engine by the magneto. It's a black plastic sensor with one bolt and a two wire cable about a foot long, or less. It's easy to change once you have the Tupperware off. Basically as the magneto spins it triggers the sensor every revolution. This indicates to the ECU that when you are thumbing the starter that the crank is actually turning.

The sensor tells the ECM the crank is turning which drives the engine tachometer. If the sensor is not telling the ECM anything, the tachometer won't flicker on startup, there will be no fuel injected and no spark. This stops the injectors continually pumping fuel into a stationary engine leading eventually to a potential hydraulic lock or a fire blowing back into the air filter.

They are very cheaply made yet proper function is essential for the engine to start and run. They love to go intermittent based on temperature and drive owners to the point of insanity.

I'm not saying this is your problem, but for $40 off Amazon for a cheap replacement, the 20 minutes it takes to change it to eliminate that as a possibility, would be where I would go next. You have covered just about every other thing I can think of, all the obvious things, I just don't really know what to suggest next other than an exorcism or a Buddhist blessing ceremony.

Thanks for the info.
I ordered one from Amazon and I will have it Friday. $23 compare to $114 OEM. I will drive the Spyder around town today to see if I have any more problems since I changed the hoses on the MAP and did the Canister thing. And when it happens I will watch the Tachometer for sure.

 

[mecsw500]

Let us know what transpires, we are all invested now.

 

[Roadsterryder]

Let us know what transpires, we are all invested now.

Will do.