2001 Optimax 225 issue

[StealinThunder]

Took the boat for a ride a couple weeks ago and out of nowhere the engine lost about 200RPM for what seemed like no reason. I bumped it back up and about 30 second later it just shut off, clean, out of nowhere. Did some checking and the ecm/injectors/etc fuse was blown. Put the extra 20A in it and it fired up and then had an injector fault.

Took it back and started pulling the injector wires off to figure out which one it was, which was #5. Turns out it had no spark either. Put a new coil on it and same thing. (turns out the old coil was fine).

I tested all the other cylinders today with an inline spark tester and they are all fine, just #5 has nothing.

I used a volt meter on the injector wires with it unplugged and both key on and then with the engine running and it seems to have no power.

I tested the other 2 on the same bank and the meter only read 2.2 volts. That doesnt seem right, but im not very good with outboards.

Is there another test I can do to rule anything else out?

I may have access to a Rhinda scan tool, can I use that to find out if the ECM is screwed up?

Engine starts and runs fine at idle, just has the beep from the injector fault.

I pulled an air hose off and it seemed ok inside, the filter is clean looking. When I purged the shrader valve there was some moisture but when it hit the water (boats in the water) and doesnt seem to have gas in it. Also appears the air injectors have been updated with the black ones with blue dots on them.

Engine has less than 200 hours on it, its on a sport craft center console. Sorry for the novel, I just try to lay out as much info that I know possible to keep the 21 questions to a minimum haha.

Thanks for reading and thank you for any insight

[Martin_80]

On my motor the DDT showed faults on the crank position sensor. The CPS was fine and the ECM was not.

You can measure the injectors resistance, I dont know the value... 2.2v does not sound right, I think it should be 12v. Since you seem to have both ignition and injector problems I would check the wire harness and earth connections. It can be a good idea to loosen the earth connections a bit and retight them. Remove battery connection first.

[XstreamVking]

All points to the computer to me.

[StealinThunder]

On my motor the DDT showed faults on the crank position sensor. The CPS was fine and the ECM was not.

You can measure the injectors resistance, I dont know the value... 2.2v does not sound right, I think it should be 12v. Since you seem to have both ignition and injector problems I would check the wire harness and earth connections. It can be a good idea to loosen the earth connections a bit and retight them. Remove battery connection first.

I was thinking the same thing on the injector voltage.

i forgot to do a resistance check on them, I'll try that this evening.

I was afraid of the ecm being killed, not what I wanted but it's a boat,haha.

I did unplug plug and check the cps and it looked good and clean.

Thank you guys for the replys

[RSWORDS]

That motor is known to have issues with the ign coils. it fail and wipes out the driver in the PCM. There was a service bulletin about it. What ever you do DON'T swap another PCM in.... You will fry that one too and have two bad computers.

[StealinThunder]

That motor is known to have issues with the ign coils. it fail and wipes out the driver in the PCM. There was a service bulletin about it. What ever you do DON'T swap another PCM in.... You will fry that one too and have two bad computers.

Yeah so I've read. The thing is is I've already put the coil that I thought was bad from cylinder 5 on #3 and it fires,so the coil isn't bad.

Can i probe the coil wires and/or the injector wires for resistance with one probe at the coil end and the other at the ecm end?

Dad has a used harness and ecm coming, what's the process of changing it without killing the new used one?

thanks

[RSWORDS]

A shop manual will allow you to test the ecm

[StealinThunder]

Well I don't have one, yet

[RSWORDS]

You can find them online. You need to test all the coils.

[StealinThunder]

After doing some further testing, the coil on #5 (the problem one) fires for the first 5 seconds and then stops...which I didnt catch before.

I ohmed 4 of the air injectors and #5 had .4, but 3 others were 1.5. That seems like a red flag to me, but would that cause the ecm to cut the spark for that cylinder?

I ohmed all the fuel injectors and they were almost indentical, all 6.

I did get a repair manual from a friend of mine, but cant find ohm values for the damn air injectors in there.

CPS ohms were spot on.

[RSWORDS]

Swap two air injectors and see if the problem follows

[StealinThunder]

Just wanted to update the thread for future reference and for people that search for this issue down the road.

It turned out to be a bad air injector. With the 555 PCM, when it sees an issue with the air injector it will shut off spark to that cylinder to keep from melting it down.

Air injectors should ohm 1-1.5 and my bad one was .4, all the others were 1.5

Thank you to guys that helped