No spark or injector pulse

[200521i]

I have a 2005 21 I 340 mp .On first start it may start up and run if left , but after turn it off and try to restart won't start . Will crank over but no spark and no injector pulse .I have changed crank angle sensor with no change . Today I checked the cam angle sensor ( with multi meter ) turning engine over by hand and it had out put voltage . Also checked ignition module ( with multi metre ) with help from (YouTube ) and seem to be ok . Have also checked for broken wires from both these components back to engine computer . Was just wondering if any body has had a similar problem . Most post say engine computer rarely fails, so I'm a bit lost what to do next . Any help would be great thanks .

[KoolAid]

My first thought was power to the ECM. '06 had a separate wire but I am not sure about the 2005.

http://marinepowerusa.com/wp-content...l_Pre-2011.pdf

Check to see where power comes into the ECM at. Verify you have power to the ECM.

[IDBoating]

Start with the simple things first: How about the emergency switch? On some ECU's, that allows cranking but prevents starting by (wait for it) killing spark and injector pulses. Your problem could be as easy as a loose wire on the switch, or faulty switch, etc.

If word on the street is that the ECU on your engine is normally reliable, then presume it's OK and look for reasons why the ECU might do this on purpose because of bad input data.

[Brianrzr]

Check the safety lanyard.

[KoolAid]

The safety switch would have allowed it to crank but not start. Not sure if the '05 had one or not. If its the rubber press in style, I would say its bad if it is the original.

[Brianrzr]

Not true. I have a merc from that time period that would fire up instantly and run for 3-5 seconds and then shut down. I spent an entire weekend checking the fuel system, ignition system everything. What I found out was the safety lanyard system was tied with the oil pressure. When the oil pressure increased it shut of the the ignition off. Lanyard wasn't even completly disconnected, just bumped enough to move the toggle. Had it just not fired, I would have checked the lanyard first. I was pissed and happy at the same time. I learned a simple rule, always check the lanyard first.

[KoolAid]

He has a marine power not a merc.
On the Marine powers the purple wire went through lanyard to the ecm for power. The starter/ignition wire (pink or red) went straight to the starter solenoid and the starter was wired directly to the battery. That is why the marine powers would crank but would not start. The ecm would never power up if the lanyard was unplugged.

[JCP]

The fact that it usually starts cold and does not restart would lessen the chance of it being a wiring or connection problem. If there is a relay involved with the power feed to the ECM, try swapping it out or bypassing. Since it is an intermittent problem, your test of the cam sensor and ignition module may be inconclusive, maybe the part was not failing at test time. Try swapping with a known good part.