Merc 240 efi won't re-start

[Tim75]

I did the old style tps swap about 4 years ago and still works well. The old pn was 14851T. Good luck finding one. I paid $125.

2 of 3 wires match color, 3rd is connected to the other odd color. Fitment & adjusting is to the book.
Who paid $60 for test harness? I found it for $25 new online. As Dr said, it can be done wthout it, but it does make the job easier.

Still seems like you have components that are failing hot-soaked. Even injectors. Check fuel pressure while hot.

 

[Andy9236]

Was there a final solution to this problem? I’m having the same problem in my 2003 speedster 240 with Merc v6 m2 efi (newer engine version). Ran fine all day Saturday, started and stopped a bit while out tubing. Then we stopped to swim and the boat would not restart. Got pulled back to the camp and once I got there it turned over just fine. First time this has happened and I would like to take it out next weekend but fear it not restarting on me and getting stuck out there.

 

[AnviL Man]

Was there a final solution to this problem? I’m having the same problem in my 2003 speedster 240 with Merc v6 m2 efi (newer engine version). Ran fine all day Saturday, started and stopped a bit while out tubing. Then we stopped to swim and the boat would not restart. Got pulled back to the camp and once I got there it turned over just fine. First time this has happened and I would like to take it out next weekend but fear it not restarting on me and getting stuck out there.

Are you making sure you properly vent the engine bay for 5 minutes or so before trying to restart? From my experience this is critical for it to restart properly. I have the 03 Speedster as well and the only few times I had a no restart is when I didn't allow enough time venting before starting. This boat has been 100% reliable since I bought it a few years ago. Never an issue but it doesn't like to be restarted immediately after shutting it off. So now that I know this I always make sure if I shut it off I leave it off for a while and also make sure to vent it for 5 minutes atleast.

 

[LesPaul]

Turned out to be the TPS (throttle position sensor). Bit the bullet and replaced it and she runs like a champ.

 

[reeyou]

Are you making sure you properly vent the engine bay for 5 minutes or so before trying to restart? From my experience this is critical for it to restart properly. I have the 03 Speedster as well and the only few times I had a no restart is when I didn't allow enough time venting before starting. This boat has been 100% reliable since I bought it a few years ago. Never an issue but it doesn't like to be restarted immediately after shutting it off. So now that I know this I always make sure if I shut it off I leave it off for a while and also make sure to vent it for 5 minutes atleast.

In my case, it was port side temperature sensor. I took it out and tested it, readings were off. It's relatively cheap and easy to replace.

 

[Sportster-2001-951C-Stock]

Yes, don't overlook the throttle position sensor. The low speed air/fuel mixture relies on this sensor.