Di run-on

[AZ Sea Doo XP]

I had a friend of mine whose Di would not shut off. He removed it from the lake, ran the engine for a few seconds and pulled the key. the engine kept running. he said it took a long time but the engine finally stopped. I wasnt there but what would you do in a situation like that? I had it happen on a carb 951. I pulled the choke and that stopped the engine. I would assume something would have to be wrong for this to happen, but what do you do to stop it?

 

[XP 787]

Air leak, you did the right thing pulling the choke

 

[manolocross]

Air leak, you did the right thing pulling the choke

Noooo he said it happened on a DI ( DIRECT INJECTION) ski... that means it DOES NOT have a choke. So the question is if a DI goes on a lean runaway.... how do you stop it??????
Good question....

 

[Coastiejoe]

Stuck DESS could cause that.

 

[XP 787]

Noooo he said it happened on a DI ( DIRECT INJECTION) ski... that means it DOES NOT have a choke. So the question is if a DI goes on a lean runaway.... how do you stop it??????
Good question....

My mistake. He said he did it once on a carbed 951. How do you stop a runaway on a DI?

 

[AZ Sea Doo XP]

I cant think of a way other than staring at it until the pistons get sticky. not a solution!

 

[jhjesse]

Did the engine runaway or just run at idle?

 

[AZ Sea Doo XP]

after a day at the lake, he put the boat on the trailer and started/revved it up. it dropped to idle and wouldnt shut off. eventually it stopped by itself a couple of minutes later.

 

[jhjesse]

No runaway. I would start by replacing dess post. Next I would Disconnect all electrical plugs clean with contact cleaner, reconnect using dielectric grease.

If no luck, maybe take a hard look at the start/stop button.

 

[Chester]

Stuck DESS could cause that.

Yup, I'd start by testing the DESS post.

Chester

 

[jasonham41]

From what your saying it didn't run away like a carbed ski, it just kept going at idle.
Very likely a sticky dess post.

 

[AZ Sea Doo XP]

how do you fix a sticky DESS post?

 

[jasonham41]

If you still have the fault active, you can try tapping the post with the handle of a screw driver or similar to confirm its the switch contacts sticking.
The only fix is to replace the switch.

 

[AZ Sea Doo XP]

so if i tap on it and it doesnt stop running, the engine may end up seizing. do you have any idea how to get the engine to stop running if tapping the dess doesnt work? thanks!

 

[jasonham41]

Safer way would be to test the switch with a multimeter. Disconnect the switch and find the wires that change open/ closed circuit. Or if you can't find a switching pair of wires that would confirm a switch fault.

 

[Chester]

Does the stop button work?

Chester

 

[Chester]

how do you fix a sticky DESS post?

By replacing it. Test it first.

Chester

 

[AZ Sea Doo XP]

Hypothetical situation. My Di engine is running. I pull the key. It keeps running. I tap the DESS post. It keeps running. My question is this. IF the engine keeps running after the key is removed, how do I stop the engine to keep it from seizing? I would think I would have very little time before engine damage occurs

 

[jhjesse]

Umm...I guess if you are "hell bent to leather" to start the ski before testing or replacing the dess post, then start it and if it won't cut off at idle then just pull the plug wires.

 

[AZ Sea Doo XP]

"Umm...I guess if you are "hell bent to leather" to start the ski before testing or replacing the dess post" why would I replace a post that is good? I want to know what to do IF I SHOULD EVER RUN INTO THIS SITUATION.
"then start it and if it won't cut off at idle then just pull the plug wires." pulling the plug wires will probably do nothing since the plugs are already hot.

 

[AZ Sea Doo XP]

I figured it out. IF the engine continues to run-on, for whatever reason, I will pull the EFI fuse. That should do it. Now I have a plan should this occur on my boat like it did on a friend of mines.

 

[jhjesse]

"Umm...I guess if you are "hell bent to leather" to start the ski before testing or replacing the dess post" why would I replace a post that is good? I want to know what to do IF I SHOULD EVER RUN INTO THIS SITUATION.
"then start it and if it won't cut off at idle then just pull the plug wires." pulling the plug wires will probably do nothing since the plugs are already hot.

Wow nice! Note to self: No more attempts to help out here.

I'm out. Good luck!

 

[AZ Sea Doo XP]

I appreciate your help! I do. That being said, couldnt I also say something similar after looking at your post in regards to the "hell bent for leather" and say "No more requests for help here"? just saying. Again, thanks for your help.

 

[Chester]

Wow nice! Note to self: No more attempts to help out here.

I'm out. Good luck!

Actually, you are right and AZ is wrong. When a DI won't shut off, pulling the plug wires will work as it's not like it's a carbureted run away. However, pulling the plug wires could damage the ignition coils. The best way is to cut power to the fuel pump or injectors by disconecting them or pulling the fuse.

Chester

 

[Chester]

I figured it out. IF the engine continues to run-on, for whatever reason, I will pull the EFI fuse. That should do it. Now I have a plan should this occur on my boat like it did on a friend of mines.

Does the stop button work?

Chester