We use boat almost every day. Over the past several weeks it became difficult to start cold. Use in evening it starts ok next morning. Skip a day or two and hard to start. Advencing the throttle usually required to get it going.

 We went away for 5 days and upon return it won't start at all. Starter runs. Fuel pumps are not turning on.

Here's what I've determined so far:

No power to fuel pumps - either when key on or starter running.

THere is power on both sides of all 3 circuit breakers. connections at circuit breakers are tight.

I do have constant on power at the ECM (red wire #1 pin) THere is constant on power at the relays but the relays do not click when key on. I did replace both relays.

Ignition power (purple wire) is present at the connector from the gague cluster.

If you think you need one then get one of these, there are only 2 models that will work,they are listed in above thread. Prices vary  http://www.ebay.com/itm/154554035521?fits=Year%3A1991%7CModel%3AMustang%7CMake%3AFord&hash=item23fc236d41:g:YWkAAOSw~sZg-viG" rel="nofollow - http://www.ebay.com/itm/154554035521?fits=Year%3A1991%7CModel%3AMustang%7CMake%3AFord&hash=item23fc236d41:g:YWkAAOSw~sZg-viG

and one of these  http://support.moates.net/f3v2/" rel="nofollow - http://support.moates.net/f3v2/  and have one of the guys on PN program it for you,you'll be in for about 200 bucks.

Or there are people who have done exactly that and resell to you for around 700

http://www.correctcraftfan.com/forum/forum_posts.asp?TID=49770&PN=1&title=2002-gt40-turns-over-wont-run" rel="nofollow - link

Grounded the specified pin on the test plug and got the fuel pumps to run. I did not attempt to start the boat.

Am i correct that the fuel pumps should run for 3 or 4 seconds when the ignition is turned on? This isn't happening. But with the test plug grounded the fuel pumps did turn on with ignition circuit turned on.

Whet turns on the ECM? Is there a crankshaft sensor that confirms that the crank is turning?

You should have turned the key the rest of the way to Start and see if it started.

The pumps will run for a few seconds when you turn the key to Run or Start and if the ECM doesn't get a signal from the PIP in the distributor to tell it that the engine is running, the pumps turn off. The PIP on the gt40 does basically the same thing as a crankshaft position sensor.

You don't get the pumps to run at all so it's not due to the PIP.

When you have the jumper installed and the key in Run (or Start), the jumper grounds the fuel pump relay (which would normally be done by the computer but in your case it's not happening)

When the relay is grounded, power goes to the pumps and in your case they ran.

This all suggests that the ECM is not performing it's grounding function for the fuel pump relay.

If it doesn't run you may have other ECM related issues

You could run the boat that way, but you'd be defeating a safety feature.

That would be a fire situation from say a fuel line leak where the engine quits and you don't turn the key to OFF in all the fire excitement, the pumps will keep on pumping fuel to feed the fire

Normally the PIP would see the engine not rotating and tell the ECM to open the ground for the fuel pump relay and the pumps would quit

Things you could check would be the ground wire connection to the engine for the ECM and you could unplug the 60 pin connector and make sure you don't have a bunch of corrosion on the pins 

Pin 52 is the ground path from the fuel pump relay into the ECM and the ground wire from the ECM to the engine completes the path to ground through some electronic wizardry in the ECM

If the engine will run with the STO Jumper are you saying that we could use the boat? I think I understand the safety concern....

And if the Engine runs with the STO Jumper is this a definitive that I need to buy new ECM? I'd be inclined to use the boat short term while I wait for new ECM to arrive.

You could call it continued troubleshooting 

And did you unplug the 60 pin connector and make sure there's no corrosion there and plug it back in.

Nothing to lose by doing these 2 things 

I'd probably unplug the lanyard/kill switch and jumper the wires together just to rule out that possibility also.

ECM plug clean

Disconnected grounds and verified continuity

With test plug pin grounded the fuel pumps turn on and the engine will start and will run if throttle advanced. It won't idle. At idle the engine starts runs for seconds and turns off.

Looks like the key switch is functioning properly.

Now am I gonna tell you to go out and get another ECM?  Hell no, I don't like spending other people's money especially when it's not a sure fix and it's expensive, but that might be the solution here.

Are ECM available new? Or is it a remanufactured part. Any suggestions where to buy?

Nautique parts I believe sources them from the person with even some more markup- http://www.nautiqueparts.com/product/gt-40-engine-control-module-ecm/" rel="nofollow - http://www.nautiqueparts.com/product/gt-40-engine-control-module-ecm/

Ordered it from GT40 Marine in Washington. Prompt ship.

Thanks to the Academy and all of you who commented on this thread. 

Now I'll have a war story to recite at Greg Fossett's next reunion! (Although I'll probably show up with my Flightcraft......)