Monsoon 335 No Start

[Trumpetrhapsody]

2003 Indmar Monsoon 335 running MEFI4. Had a senior moment and routed the cannon umbilical between the manifold crossover and manifold, which melted the sheathing on the grey and light blue ( supposedly tacho and oil pressure ) wires while underway. Popped two fuel pump fuses and much cranking (stranded) before getting towed in and finding the melt. Cleaned up the wires, new fuse, but now it seems like I'm not getting any spark. I'm getting a DTC 81 (12 12 81) from the OBD paperclip/LED trick, so I have a MEFIburn scanner coming in later this week to get the specific sub-code. I've checked all the fuses and relays, connectors all look healthy, distributor and coil have power, it just seems like the ECM isn't commanding spark or the coil/dizzy aren't doing their job.

I'm concerned that I've fried the ECM. I read some folks saying the ECM is sensitive to low/high voltage, and that a reflash has solved issues similar to this. I contacted Indmar customer email support (they responded within 30min on Memorial Day, amazing!), and they said their Diacom files aren't compatible with MEFIburn so doing my own reflash isn't an option. I'm not sure if that's true or if they just don't want to give them out. They didn't think a reflash would help anyway, calling the 81 codes "inconsequential" and saying the engine usually still runs with them.

We'll see what the scanner says I guess. I believe the folks who make MEFIburn offer ECU repair, so either that or shipping it to Indmar might be an option before I straight replace the ECM ($$$$).

Edited May 29, 2018 by Trumpetrhapsody

[MadMan]

8 minutes ago, Trumpetrhapsody said:

 melted the sheathing on the grey and light blue ( supposedly tacho and oil pressure )

I believe the tach wire is driven by the ignition module in the distributor, you could replace it with an auto parts store one.

[electricjohn]

Code 81 is 1) fuel pump driver circuit failure.

                    2) injector driver circuit failure.

                    3)sensor reference voltage out of range. 

You are correct with the wire colors, but the tach signal comes from the ECM (terminal J1-14), not the distributor.

[Trumpetrhapsody]

4 hours ago, MadMan said:

I believe the tach wire is driven by the ignition module in the distributor, you could replace it with an auto parts store one.

The more that I think about it, the more a dead ignition module makes sense. If it fried, it might be throwing the voltage ref out of range. I would also expect the module to try to run the engine at base timing even if the ECM was having troubles. Thanks for the suggestion - i'll pick one up locally and give it a try.

[98sportsterlx]

Just throwing this out there but I have a spare unused ecm for mefi 4b if that is the one you would happen to need if you determine yours is bad. I bought one last year from Bakes  because mechanic said it was bad when it was not the problem and I was unable to return it. I could make you a killer deal on it.

 

[Trumpetrhapsody]

On 5/29/2018 at 8:11 PM, 98sportsterlx said:

Just throwing this out there but I have a spare unused ecm for mefi 4b if that is the one you would happen to need

 

Thanks! I'll give you a yell if it comes to that.

 

Just replaced the ignition module, but still no spark. Dang, and I was so hopeful. I'm going to toss a new autoparts coil at it as one last hail mary. Otherwise I'll have to wait and see what the scanner says when it comes in tomorrow.

[Trumpetrhapsody]

... it was the ignition coil. Back in business.

Edit: For the record, i'm now running a BWD brand ignition module and ignition coil. Unknown if the ignition module was a factor or if it was JUST the coil, since the problem persisted until the coil was replaced. From what I can tell via what I've read, there shouldn't be any danger compared to "marine" components, unlike a starter or alternator. Reliability is the main concern. I think i'll give them a shot, and report back if I have any problems.

Edited May 31, 2018 by Trumpetrhapsody