Won't start, fuel pump never stops

[gregski]

'07 Indmar won't start, but here's the twist: the fuel pump won't stop running. Normally the pump runs for 2-3 seconds after you turn the ignition on and then stops. But when I turn the ignition on, the pump just keeps running and running. I've got fuel and good pressure in the supply rail, spark at the plugs, it cranks but won't start. I'm really scratching my head this time. Any ideas?

The never-stop-running fuel pump is my only clue or indication that something is different. This makes me think about ECU issues but since the pump is turning on, the ECU is at least alive, right?

[Branden967]

I believe there’s a relay between the ecu and pump. I’d check check that first before the ecu route. It maybe is just stuck on.

[gregski]

I have 1.38V at the sensor 5V references (crank, cam, MAP tested so far). The diagnostic flow chart pretty much says it's time to replace the ECM but that seems like an expensive next step, especially without a known root-cause - I'd be afraid that a new ECM would fail the same way. Has anyone been down a similar path, anything else to check?

[gregski]

Solved. While in storage this spring, there was a lightning strike nearby which fried some things like modems, routers a pump controller, and the ECM on our boat. Basically, the boat was attacked by an EMP. I just got a replacement ECM installed and everything is running great again. This happened just a couple of days before we picked it up

This was a real head-scratcher. All the signs were pointing to the ECM but I was reluctant to buy a new one at $900 just to "test it out". Thanks to Larry at Indmar for referring me to OBD Diagnostics, www.mefiburn.com. I had been on their website before but missed that they can do bench-tests, diagnostics and repairs for the MEFI ECMs. Our ECM was fried beyond repair but it sounds like most common problems are repairable so this is a very valuable resource to have available.

For storage, I remove the batteries and just leave the battery cables lying where they are. I'm now thinking that I should clamp the positive and negative cables together to help protect against this kind of thing.