Hot Restart Issue.

[Yamijunkjones]

2017 ar195, 1.8 s/c. runs great all day no hiccups or loss of rpm or any issues for that matter. That is until your shut the boat down for a minute. Try to start this mofo back up and you’re stranded for a solid 30 minutes cranking away until finally you’re lucky enough to get it to fire off. Then your back to trouble free boating. Just don’t shut it back down or you’re stranded again.
boat cold, starts no problem.. every single time
Now I know people are going to chime in saying oh these are always hard to restart hot blah blah, sounds like vapor lock.
well this is not the case. First of all your fuel pump is submerged in fuel not drawing a vacuum on the rail so vapor lock doesn’t seem logical unless someone can give me a logical explanation otherwise.
Fuel pressure maintains 53 psi hot at rail
Fuel injectors have been removed, flow tested, leak down tested
Valve lash is perfectly within across the board
Compression 135 1-4
Leak down tested held
Clean spark maintained when hot
Cam sensor has been replaced
Ecm has been swapped with good know unit (no change)
Etv angle is 6%.. usually they sit around 4% so I’m not ruling this out yet. However Yamaha says 3-7% is fine
I’ve checked for vacuum leaks, disassembled intake manifold to check delaminating on Etv isolator.
Engine temp in YDIS shows 180 F when I’m out beating on it, I’ve confirmed this value with my infrared flir gun at the temp sensor.
none of my values are out of range on my sensors everything from service manual to Yamaha support line is within spec.

I’ve also tried unplugging each 5v reference sensor 1 at a time while the engine was hot to see if the engine would kick off when hot (no luck)

I know there is a wizard out there somewhere that can make since of this sorcery, please chime in

 

[Dixemon]

Thats alot of work trying to track the problem down, much respect. I have heard of exhaust leaks filling the engine compartment and displacing oxygen causing issues. Have you had any success reproducing the failure while flushing on a hose out of the water? How about, on /Off the water, do you open the hatch and allow fresh air to circulate prior to trying to restart. Pull the air filter and try and see if it starts easier? Good luck, im sure everyone here will appreciate hearing the solution to this issue, it has been brought up numerous times.

 

[FLJetBoater]

Thats alot of work trying to track the problem down, much respect. I have heard of exhaust leaks filling the engine compartment and displacing oxygen causing issues. Have you had any success reproducing the failure while flushing on a hose out of the water? How about, on /Off the water, do you open the hatch and allow fresh air to circulate prior to trying to restart. Pull the air filter and try and see if it starts easier? Good luck, im sure everyone here will appreciate hearing the solution to this issue, it has been brought up numerous times.

I know in my situation it happens both in the water and on the hose. And when running on the hose the engine compartment was open.

 

[dzeppos]

My 242 is saying the same issue on really hot 100F-110F or more days when running it hard. My engines start but will immediately stall. Opening the engine hatch, the gas cap, and even running the engines at idle for 3-4 minutes before shutting down seem to help mitigate the issue. I can usually get it to start and stay on after 2-3 starts and hitting the no wake mode (to up the rpms). This is also more likely to happen when wake surfing with a ballast (but can happen without doing any water sports) on the back and pulling wake surfers at 6100rpms for long stretches at a time.

 

[Yamijunkjones]

Thats alot of work trying to track the problem down, much respect. I have heard of exhaust leaks filling the engine compartment and displacing oxygen causing issues. Have you had any success reproducing the failure while flushing on a hose out of the water? How about, on /Off the water, do you open the hatch and allow fresh air to circulate prior to trying to restart. Pull the air filter and try and see if it starts easier? Good luck, im sure everyone here will appreciate hearing the solution to this issue, it has been brought up numerous times.

My 242 is saying the same issue on really hot 100F-110F or more days when running it hard. My engines start but will immediately stall. Opening the engine hatch, the gas cap, and even running the engines at idle for 3-4 minutes before shutting down seem to help mitigate the issue. I can usually get it to start and stay on after 2-3 starts and hitting the no wake mode (to up the rpms). This is also more likely to

So I have removed my intake box completely, engine hatch open, getting as much fresh air as possible into engine bay with no change. I can duplicate the issue on hose if I choke my water down a bit and get the engine temp up to mimic lake around 180f. Also should note that hole fuel system has been cleaned and filled with fresh 93 octane fuel. I’m still curious as to why my Etv angle is showing 6% I’m going to dig into this further today. I will report back

 

[Yamijunkjones]

Also for a little knowledge, these boats aren’t equipped with a enricher nor does the ecm recognize a cold start from a hot one, each start up is the same, the ecm batch fires the injectors causing every start to be considered a cold start, this is why these start like shit when hot. However I’m very familiar with hot restarts taking a few cranks to get these to fire. My boat just will not start for the life of it until engine temps drop to near ambient air temperatures

 

[motomark73]

Mine is worse when wake surfing also. My current theory is higher loads cause higher running temps exacerbating the situation. I found some related Yamaha ECM threads for outboards on the Hull Truth. I'm assuming their ECM control logic is at least similar. The basic premise is either a relay or sensor is beginning to fail short and drawing down the 5V signal for all ECM inputs, making it nearly impossible to troubleshoot. ECM will allow motor to keep running even as there is a "developing" issue as the heat induced parasitic loss in the bad component pulls the entire ECM 5V baseline down. When you shut motor down and try to hot start, the ECM is now below 5V; there may be more stringent controls in place that wont allow motor to start or possibly you just end up with a calculated fuel and spark timing based on bad system voltage that just won't support ignition. As motor cools, the failing component starts acting normally, the parasitic loss on the 5V baseline goes away or gets to a threshold where the calculated value falls into normal range as if you were back a 5V baseline and all control logic begins working again. Not sure if there is any merit to this, but it could explain why it is so hard to troubleshoot. The parasitic loss on 5V baseline could probably be any # of components or even a poor ground in a harness somewhere.

 

[FLJetBoater]

Mine is worse when wake surfing also. My current theory is higher loads cause higher running temps exacerbating the situation. I found some related Yamaha ECM threads for outboards on the Hull Truth. I'm assuming their ECM control logic is at least similar. The basic premise is either a relay or sensor is beginning to fail short and drawing down the 5V signal for all ECM inputs, making it nearly impossible to troubleshoot. ECM will allow motor to keep running even as there is a "developing" issue as the heat induced parasitic loss in the bad component pulls the entire ECM 5V baseline down. When you shut motor down and try to hot start, the ECM is now below 5V; there may be more stringent controls in place that wont allow motor to start or possibly you just end up with a calculated fuel and spark timing based on bad system voltage that just won't support ignition. As motor cools, the failing component starts acting normally, the parasitic loss on the 5V baseline goes away or gets to a threshold where the calculated value falls into normal range as if you were back a 5V baseline and all control logic begins working again. Not sure if there is any merit to this, but it could explain why it is so hard to troubleshoot. The parasitic loss on 5V baseline could probably be any # of components or even a poor ground in a harness somewhere.

Very interesting!
my boat has been in active “service” at the dealer for over 1.5 weeks now and I know that @73 vega has his in and Yamaha corporate techs haven’t had much luck yet either.

 

[I_squared_r]

It looks like you've checked a lot of things, but I would suggest going back to the basics and start from there. I can think of 3 problems causing the hard start:
1. No fuel
2. Too much fuel
3. Weak spark

Try to narrow it down.
1. Take out the air filter and spray starter fluid into the intake while cranking it.
2. Remove the spark plugs and crank over the engine to remove excess fuel. Reinstall and try to start again.
3. Install adjustable ignition spark tester on each individual coil. I would see how many KV you're getting on each coil. Maybe you have 1 or 2 weak coils

 

[sx998]

Had this with my 192. I changed the Stator / Pickup coil. Cylinder 1 and 4 would spark but not 2 and 3. Try checking those cylinders for spark next time it doesn’t want to fire.

 

[FLJetBoater]

Had this with my 192. I changed the Stator / Pickup coil. Cylinder 1 and 4 would spark but not 2 and 3. Try checking those cylinders for spark next time it doesn’t want to fire.

The pickup coil requires the engine to be removed right?

 

[sx998]

Yes. Probably best to test it with a meter first. The plug is in the back of the engine.

 

[ReelFishingSWFL]

Having similar issues did you ever resolve this? Was it the coil?

 

[LoWeLL216]

Mine does this as well (2016 AR240). Never both engines - always just one.

I don't know why this seems to work, but what I do is use the running motor to slowly pull forward then start the other one.

It almost always works. I have no idea mechanically why this would make a difference.

 

[Beachbummer]

I am curious if trying to start with wide open throttle for a few seconds helps... Followed by normal start.


My theory is that there may be a slow fuel leak from injectors, and allowing the engine to crank at full throttle would move enough air to fix the mixture.

Just a thought.

 

[FSH 210 Sport]

I am curious if trying to start with wide open throttle for a few seconds helps... Followed by normal start.


My theory is that there may be a slow fuel leak from injectors, and allowing the engine to crank at full throttle would move enough air to fix the mixture.

Just a thought.

The throttle lever will not allow that since there is a lockout that prevents starting at anything above idle.

EFI dirt bike has the issue of a fuel injector leaking down after shut off… fine if you started it right back up, but if it sat for 15 mins or more it would take a while to get started. A weak battery that allows voltage to drop below 10.5 volts will also impact hot restart capability. Running too high of an octane fuel will also affect hot starts.

I’ve had the issue twice I think, what I do now after running hard is to wait until the oil cooler discharge water is cool to the touch, and while I’m waiting for that water to cool down I run the bilge blowers to get all the hot air out of the engine bay.

 

[Beachbummer]

Our older throttle mechanism had a button at the base of the lever to increase rpm while on neutral and it would still crank. Probably things have changed.

 

[lazergeek]

I think @ReelFishingSWFL already replaced injectors and ECU which should have eliminated a leaky injector. He has some other stubborn gremlin.

 

[FSH 210 Sport]

I think @ReelFishingSWFL already replaced injectors and ECU which should have eliminated a leaky injector. He has some other stubborn gremlin.

And I think he found another issue that seems to have solved the starting issue.. he found heavy, and I mean heavy corrosion on the back of the fuse box where one of the multi pin connectors attaches. I think he said that fixed his hard start issue, but now he thinks he has an over heat on the hose, I told not to worry about issues on the hose, go out and run it and have some fun.

 

[ReelFishingSWFL]

And I think he found another issue that seems to have solved the starting issue.. he found heavy, and I mean heavy corrosion on the back of the fuse box where one of the multi pin connectors attaches. I think he said that fixed his hard start issue, but now he thinks he has an over heat on the hose, I told not to worry about issues on the hose, go out and run it and have some fun.

Well, I thought I found the issues today. It gave me a hard time again, and finally, it stopped working completely. I discovered that I'm not getting fuel to the injectors. At first, I thought the ECU went out again! However, when I plugged it into my friend's boat (which is the same model), it started his boat without any problem. I also used his ECU on my boat, but it still had the same issue of a hard start, or rather, no start at all. After that test, I ruled out the ECU as the problem. Now, I suspect it's the Pulser coil causing the trouble. I have checked every single safety switch, and they are all fine, including the neutral switch. My technician plugged in his computer, but I'm not getting a Pulser coil code. However, what's strange is that the motor is spinning at 250 RPM at startup without spraying fuel, while it should be around 600 RPM to start. After making several calls to different dealers and talking to master technicians, most of them believe that the Pulser coil is the reason why the RPM readings are incorrect and the injectors are not spraying. Another thing worth mentioning is that the motor definitely sounds like it's spinning a lot harder than 250 RPM. What do you guys? think?