Mercury 240 efi engine won’t start after trying all

[ed8widge]

2003 seadoo utopia with mercury engine 240 efi . Voluntary stop engine at sea and never want to start again. All seem normal, test spark plugs, test filter, test compression, check sensor but still no start . Tried everything no luck @Dr Honda @tim any one anyidea???

 

[CarewPat]

The first thing you'll want to do is confirm you have spark. This can be done using a spark gap tester.

Disconnect all spark plugs. Attach the tester to each spark plug wire and attach the other end of the tester to a good ground. Have a friend crank the engine and confirm you have a good bright blue spark on every cylinder.

 

[ed8widge]

The first thing you'll want to do is confirm you have spark. This can be done using a spark gap tester.

Disconnect all spark plugs. Attach the tester to each spark plug wire and attach the other end of the tester to a good ground. Have a friend crank the engine and confirm you have a good bright blue spark on every cylinder.

I have spark, on each plug and wire.

When I took the first plug out, the engine runs on 5 cylinders, when I put the plug back in it will not run. The battery is new 12volts on my tester. Can it be a starter motor that does not have enough power for the engine compression? How do I test Starter to know if it turns the engine enough?

 

[Tim75]

Check your vst pressure.
Check the injector wire harness. Connector is round, low, starboard, 4 wires. No green connections allowed.

Does the starter turn the engine with 6 plugs in?

I have spark, on each plug and wire.

When I took the first plug out, the engine runs on 5 cylinders, when I put the plug back in it will not run. The battery is new 12volts on my tester. Can it be a starter motor that does not have enough power for the engine compression? How do I test Starter to know if it turns the engine enough?

.

 

[ed8widge]

Check your vst pressure.
Check the injector wire harness. Connector is round, low, starboard, 4 wires. No green connections allowed.

Does the starter turn the engine with 6 plugs in?


.

Ok, I will check the vst, I don't have the adapter that goes to the little valve in the side . Can I use the exit hose to check the pressure?

 

[Dr Honda]

Don't need an adapter. It's a standard shrader valve to a tire. Just use a lock-on style tire pressure gauge.

 

[ed8widge]

Don't need an adapter. It's a standard shrader valve to a tire. Just use a lock-on style tire pressure gauge.

fuel pressure is 34 psi, but what I realized it only stars cold. It quickly starts at the turn of the key, connected the water hose let it run about 5mins to warm up and again will not start no matter how much I tried.
This morning I tested the temp sensor, I got 9000 ohms when cold on both. Could it be the sensors? It wouldn't turn off when started but won't start again when hot, why? Last time I was in the middle of the ocean when voluntary turn it off and it wouldn't start. Any Idea? thank you

 

[Dr Honda]

Normally... with what it's doing, it's because the engine is flooding. (fuel) When the injectors are going bad... they leak. So, when you turn off the engine... the pressure in the system pushes what's left of the fuel in the injection system, into the engine. That wets the spark plugs, and makes it hard to start. BUT... after a few hours... that evaporates, and it will restart.

Try this again, and see if it holds pressure in the fuel system... and for how long. Next... pull all the spark plugs, and crank it over for a few seconds... put the plugs back in... and see if it starts. I know it won't be easy with it hot... but it could help. Also... check the resistance of the temp senders hot.

 

[ed8widge]

will do, first thing in the morning

 

[Blackbartman]

I am having this same issue on my 2001 Challenger 240 EFI M2. It starts up cold in literally 1 second and will run strong all day. It runs between 5800 and 6200 rpms at a top speed of about 46. Compression is 120 across all 6. But when I shut it off, I get one chance to restart it by turning the wheel all the way left. Sometimes works sometimes doesn't. If i try to start it without turning the wheel it will not start. After that it floods out and simply will not restart for about 2 hours. It has spark and obviously fuel because it floods. I will try testing the fuel pressure and see if it drops after running it and parking it. How hard are the injectors to remove? (If I am putting anyone off by jumping on this post, please tell me and I'll stop).

 

[ed8widge]

Normally... with what it's doing, it's because the engine is flooding. (fuel) When the injectors are going bad... they leak. So, when you turn off the engine... the pressure in the system pushes what's left of the fuel in the injection system, into the engine. That wets the spark plugs, and makes it hard to start. BUT... after a few hours... that evaporates, and it will restart.

Try this again, and see if it holds pressure in the fuel system... and for how long. Next... pull all the spark plugs, and crank it over for a few seconds... put the plugs back in... and see if it starts. I know it won't be easy with it hot... but it could help. Also... check the resistance of the temp senders hot.

I pulled out all the plugs. I got them all flood with fuel. I was genuinely afraid that it could be the injectors ( expensive ). I read the book again and find out that if the regulator on the vst wasn't working that also would also cause too much pressure delivered to the injectors therefore engine will flood. I checked the regulator and changed the vacuum hose apparently it was clogged and that resolved. I did turn it off started it back on like 4 times, the rest is to try it in the water hoping that was the problem. I don't know if I still have problem with my injectors , I recall the book mention that without the regulator the pump can deliver up to 90 psi of pressure. I guess that was too much for the injector to stay closed.
I will update over the weekend, thank you so much all for your advices.

 

[Tim75]

I pulled out all the plugs. I got them all flood with fuel. I was genuinely afraid that it could be the injectors ( expensive ). I read the book again and find out that if the regulator on the vst wasn't working that also would also cause too much pressure delivered to the injectors therefore engine will flood. I checked the regulator and changed the vacuum hose apparently it was clogged and that resolved. I did turn it off started it back on like 4 times, the rest is to try it in the water hoping that was the problem. I don't know if I still have problem with my injectors , I recall the book mention that without the regulator the pump can deliver up to 90 psi of pressure. I guess that was too much for the injector to stay closed.
I will update over the weekend, thank you so much all for your advices.

My regulator seems to have died a couple of years ago. I had 80psi at vst. $300 for reg. I installed a racer regulator and set it for 36psi. All good. Also had injectors serviced. The best $120 spent on the engine. Higher RPM, less fuel consumption, better acceleration, smoother idle. Don't bother with "miracle cures" in a bottle. They don't work. Injectors need to be removed and serviced on a flow bench. Every big city probably has a shop that can do it. Merc charges about $800 for 6 injectors. Keihein (sp) Japanese brand.

Getting them out is not too bad; if you like standing on you head bent over and stretching your guts on the back seat. 12 bolts, 2 nuts, 3 hoses, 3 electric harnesses. Approximately. If you pay attention to the details called out in the service book, you can install 2 larger bolts to remove the throttle body intact. You will need to order the 3 gaskets. Check all the small black hoses for security and cracks. Inspect reed valves while you have throttle body removed.

 

[ed8widge]

thanks to all specially Dr Honda and Tim, Boat is running fine now,until next question.

 

[Blackbartman]

2003 seadoo utopia with mercury engine 240 efi . Voluntary stop engine at sea and never want to start again. All seem normal, test spark plugs, test filter, test compression, check sensor but still no start . Tried everything no luck @Dr Honda @tim any one anyidea???

Did you ever solve this issue?