240hp Efi v6 2004 no spark

[No spark]

Hi all, I went to start my Seadoo 240 efi v6 and it wouldn’t start so I checked if there was spark : There is No spark on any of the 6 cdi coils. So I checked the cut off lanyard
The black and yellow wire and followed it all the way back to the ecm disconnected it and checked it for ground :No ground (until I pull the lanyard out) so I think it’s all good that side of the ecm?
Then I went to the black and green wire wire coming from ecm to cdi unit’s I understand that this goes to the pin B of all cdi units ? When I check this for ground :YES it is grounded . I’m now not sure what to check now. Help would be much appreciated.

 

[Tim75]

Hi all, I went to start my Seadoo 240 efi v6 and it wouldn’t start so I checked if there was spark : There is No spark on any of the 6 cdi coils. So I checked the cut off lanyard
The black and yellow wire and followed it all the way back to the ecm disconnected it and checked it for ground :No ground (until I pull the lanyard out) so I think it’s all good that side of the ecm?
Then I went to the black and green wire wire coming from ecm to cdi unit’s I understand that this goes to the pin B of all cdi units ? When I check this for ground :YES it is grounded . I’m now not sure what to check now. Help would be much appreciated.

Check all your ground wires. Both ends. There are several. No green connections allowed.

 

[No spark]

Hi, I have checked all ground wires took them off cleaned and checked. Would there be a way to check the ecm?

 

[Tim75]

Hi, I have checked all ground wires took them off cleaned and checked. Would there be a way to check the ecm?

No one has found a place to check ecm s. Only the maker. Motorola, I think. They are not known for failing. Google testing Mercury Marine ECM.

 

[Hawk111]

Check the damn 20amp yellow fuse inside the square black cover on side of engine

 

[No spark]

Hi the fuse is good all connections cleaned and checked .
Is there a way to check the crank sensor and if this failed would the spark stop?
Is there any way that the key switch would have a way of stopping the spark other than the yellow and black wire going to ground?

 

[IComeFromALandDownUnder]

I'm in exactly the same situation as you albeit my 2004 240efi v6 mercury is installed in a Sugar Sands.
Have you checked the CPS (should be between 306-315 ohms when turning the flywheel)?
Also check voltage across the battery whilst cranking. Should be >9.5v.

 

[cbatstone]

I have the same issue now with my 2005 SeaDoo Utopia with a 2004 Mercury 240 EFI (SN: 0E425879 - alternator/CPS version. Not getting spark to either bank of the 6 Cylinders. The boat stopped suddenly when the failure occurred.

-no water in fuel/water separator, replaced
-when key is turned, long audible beep is heard (normal)
-Confirmed open circuit on yellow/black wire in the console to the negative battery terminal with key in ON position.
-CPS Resistance 323
-I have ordered by don't yet have a service manual.

Has anyone had anything to report, any findings or suggestions of where to check next on these engines?

 

[IComeFromALandDownUnder]

I managed to find the fault in mine. It turned out to be a broken earth wire (to the coil packs) at the connector block near the top rear of the engine. In my case it was particularly difficult to find as the earthing paths at the coil packs tested ok. The problem only occurred when turning the engine over and I had to use an oscilloscope to determine what was wrong.
The oscilloscope ($100 usb one off ebay) was invaluable as it let me see the pulse signal at the packs and check each earth as the engine was cranking over. BTW the boat had already been to two mechanics and both said it was the ECM. Lucky I didn't pony up for a new one at $3500 that would've been a waste of money!

 

[cbatstone]

On mine, the Coil Packs are grounded to the plate they mount to which is grounded to the block via an exposed short piece of metal webbing, like a wide braded metal wire without any insulation. Was this wire your issue, or something else? Trying to understand what you said was hard to find so I can check it. Thank you!

 

[IComeFromALandDownUnder]

That's different to mine which has a s/n of OE426nnn. Is yours an Optimax or maybe it's been modified? I only have one connector (with 5 pins) going to each coil.
Here's a picture of mine...

 

[cbatstone]

Not an optimax, looks the same as yours. I'm just trying to understand where/what you are describing, and more about what you had to do to fix it. At the connector block, are you saying that in the connector itself the ground wire (unsure which color) was bad?

I was thinking you were describing the ground mount to the metal plate the cdi coils are all mounted to.

 

[IComeFromALandDownUnder]

The coil packs are not grounded through the two bolts that secure them. If you remove the connector to a coil pack you'll see 5 pins (a-e). These are:
A: EST (electronic spark trigger). This is the trigger from the ECM.
B: EST low. This is the return gnd path to the ECM.
C: secondary gnd (black)
D: primary gnd (black/white)
E: +12v (red/yellow)

I'd start by checking 'E' (the 12v) feed. This goes to the 20a fuse and should be live when ignition is on. Then check ''D' (primary gnd) continuity against the engine block.

 

[IComeFromALandDownUnder]

So my problem was a broken wire going into the connector block on the back of the engine (circled in red). The wire had broken just where it went into the underneath connector. The earth wiring from each pack is joined into one wire before this point so it affects all coils. My continuity checks at the coil packs were perfectly ok however when cranking there was a disconnect. Could only see this using an oscilloscope.

 

[cbatstone]

Making progress...
I'm not seeing +12v on E: Red/Yellow at the CDI Coil, and I'm not seeing +12v in half of the fusebox to the same Red/Yellow wire. I do see +12v on one side of the fusebox where the 20 & 15A fuses are. The 20A in that bay is the key-on circuit as re-setting the fuse gives the long beeeep and actuates the main Relay, which is where my issue is.

When the main power to the engine is enabled by the Key turning to the ON position, the main Relay is activated with an audible click, and then de-activates about 2 seconds later. During this brief moment where it's electromagnet is energized, I have 12v to the other side of the fuse box (Red/Yellow Wire). I need a hypothesis for why the solenoid would dis-engage on its own after 2 seconds.

Additionally I cleaned/sanded all the red power wires going onto the main Solenoid post, Checking, Sanding and Torqueing every ground I can find for good measure. Still no electrical diagrams yet as I'm waiting for the manual to be delivered.

 

[IComeFromALandDownUnder]

When the ignition is turned on, the ecm completes the gnd circuit for the main relay for a short time (which runs the fuel pump ready for start up). This is about 2 seconds. It won't re-energise again until the ecm receives a pulse from the crank position sensor when you crank it over to start. Check the 12v again whilst cranking over.

 

[IComeFromALandDownUnder]

BTW I got my manual as a pdf off eBay. Only $10 and delivered to my email next day. Absolutely invaluable!

 

[cbatstone]

When the ignition is turned on, the ecm completes the gnd circuit for the main relay for a short time (which runs the fuel pump ready for start up). This is about 2 seconds. It won't re-energise again until the ecm receives a pulse from the crank position sensor when you crank it over to start. Check the 12v again whilst cranking over.

All makes sense as jumping the relay runs the fuel pumps indefinitely. I pulled the coil connector, tested the CDI terminal E - yellow/red while cranking and like you said after a few revolutions I get 9 volts, but not 12.

I did notice one rib of the alternator belt had tore/spun off and I was thinking this could have damaged the CPS but from what you say the ECM is getting signal from the CPS if it is supplying power to the coils. I would think the CPS either works or doesn't and would not be responsible for the voltage sent to the CDI terminal.

My manual arrives later today or tomorrow but I am out of ideas. The grounds on the CDI terminals seem to check out and the connector pack where yours was broken shows no sigh of wear, top or bottom. I had my battery tested by a shop and it is fine, and fully charged.

 

[cbatstone]

The Crank Position Sensor may still be at fault. I don't have the testing specs for it and one thing I did notice was that the belt lost a full rib, as in stripped from the belt. The report of when the engine failed was right after a cavitation event where the engine revved high, which may have been the moment the strip peeled off and damaged the CPS along the way. Conflicts still with the fact that at least 9v is still getting to the CDI harness, but the report of the incident can certainly place the CPS at the center of damage whenever that belt did come apart.

Any CPS testing info in the manual I can reference?

 

[IComeFromALandDownUnder]

Keep going..it sounds like you're making great progress. I would day the CPS is ok as, like you say, the ECM has received a signal from it and is activating the relay. The voltage level to the coils won't be dependent on the CPS. My laptop is at work so give me a couple of hours and I'll see if there's a CPS test procedure...I'm sure there is. I tested mine by disconnecting the cps harness and testing the resistance as I manually turned the flywheel by hand. Checked that the resistance changed as it went past a 'tooth'.
Can you measure the voltage between the battery + and pin 'E' on a coil whilst cranking. You should get close to zero volts I'd imagine. If not then work back to the 20a fuse to see where the voltage drop is occurring.
I know I probably sound like a broken record but you may have to invest in an oscilloscope. I blew $800 at marine mechanics (one was a Mercury specialist) and neither could diagnose my problem.

 

[IComeFromALandDownUnder]

The manual only says that cps should be between 320-350ohms between the two sensor pins (yours was 323 I recall). No other testing is mentioned for it unfortunately.

 

[IComeFromALandDownUnder]

How did you go?

 

[cbatstone]

It was a flurry of troubleshooting over my vacation week at the lake. I'm now back home and 4 hours away from the boat so I won't get back until early September to hopefully get it running before bringing it home for the winter.

I did take my 2 year old Gel Cell battery to the auto parts store to have it tested and they charged it over night to eliminate that variable.

The way the boat failed (while running under power, suddenly, at a time of cavitation with momentary increased RPM's. My hypothesis for now will be that the CPS Failed when the the aftermarket alternator belt (1 rib too tall) came apart finally at that high rev, beat the snot out of the CPS wearing a solid groove in the top and causing it to malfunction (in some way that an OHM reading doesn't catch) before throwing that strip of belt to the engine bay.

It makes sense, and its relatively cheap to find out. So hopefully I'll have a better update in about a month or so to eventually close this one out. Thank you for all of your help, understanding the logic of the systems was very helpful, and your advice gave me several paths to follow to keep moving on it.

 

[IComeFromALandDownUnder]

You're more than welcome. I concur with your thinking about the CPS and when I was trouble shooting mine I changed that out first as it was relatively cheap.
Best of luck and let us know how you get on.

 

[cbatstone]

So I've returned the boat home, and have it at the shop of a local auto mechanic I use. He and I went through it again last night. I have the full mechanical manual at my disposal, and I understand the startup ignition sequence. I have verified that the CPS Does not appear to be the issue, as the main relay re-energizes after cranking and the 9.5+ volts is seen on at the coil packs on the red/yellow wire.

I believe the only remaining items would be a grounding issue of some kind, or the rare-to-fail Motorola ECM not completing the grounding of the coils driver for each spark impulse. I am not aware of anything else which could prevent spark at all 6 coils so let me know if you know otherwise. With the ECM said to rarely fail, I'm at the moment assuming it is not the problem. I will remind here now that the engine did shut off suddenly while running and under load.

I've got some follow up questions about your use of the oscilloscope in locating a bad ground. He does have an oscilloscope and he suggested a test light to actually pass current through the grounding wires, so we do plan to do that at each segment of wire between the ECM > Big Coil Pack Connector > Individual Coil Packs

Can you describe the method in which you used the oscilloscope to find your grounding issue? Did you have everything connected and then back-tap the connectors? Looking for any guidance to narrow down the suspects and test this properly.