Intermittent loss of power (long winded 1st post)

[OnPad]

Here's another test to try.

[rgsauger]

Just for grins, have you run a compression check on all six holes?

[PanRonnie]

i have added the techniciens guide
the ADI ignition is the old system
yours is the CDM ignition

[80Grady]

Pulled the CDMs today and checked resistance. All 6 tested close to the same. My only concern was that when using the procedure above, I had no resistance when going from -D to +B on any of them. All had almost equal resistance when reversed to -B to +D. Is theis due to them being removed or from possibly not using the factory test harness. I just used my meter leads on the CDM pins directly.

[80Grady]

Yup, all around 120 +/‐ 3psi. Have not performed a leakdown test though.

Just for grins, have you run a compression check on all six holes?

[80Grady]

Thanks. Some helpful info there. I also downloaded the troubleshooting guide from CDI.
The biggest headace is it seems like most of the faults have to be found when occurring. Difficult to do when intermittent. The fact that it randomly kicks in and takes off always has me a bit nervous when hanging over the back of the boat trying to check things. Lol.
Currently it's in the lower 30s here on the Chesapeake, so it's only driveway testing for me right now. Wish I had a known working TPM or ECU just to rule those out. Or to easily find that one is the problem.

i have added the techniciens guide
the ADI ignition is the old system
yours is the CDM ignition

[PanRonnie]

Smalltown already Mentioned this but a toggle/relay to your fuel pump can eliminate ecu pump driver issues
Also a cheap thing to do

[Davidlake]

Thanks. Some helpful info there. I also downloaded the troubleshooting guide from CDI.
The biggest headace is it seems like most of the faults have to be found when occurring. Difficult to do when intermittent. The fact that it randomly kicks in and takes off always has me a bit nervous when hanging over the back of the boat trying to check things. Lol.
Currently it's in the lower 30s here on the Chesapeake, so it's only driveway testing for me right now. Wish I had a known working TPM or ECU just to rule those out. Or to easily find that one is the problem.

My bet is still coils, due to being an intermittent issue. You might price the coils. It not too spendy, it may be a short "rabbit hole" to chase. Watch out for the Chinese knock offs, though.

[PanRonnie]

not that bad a price!

[OnPad]

To answer your question in post 19, you did the right thing, reversing meter leads and retesting.
With intermittent electrical problems, sometimes it helps to hit suspected components with a heat gun and retest.
I also wouldn't rule out fuel system with some of the symptoms you presented in post 1.
Be thorough in your testing, start with cdm trouble shooting chart 1, then jump to chart 3.
Here's another pic, should have been added to post 16.

[80Grady]

Haven't had the time or decent weather to troubleshoot any farther yet, but I did find a friend with a Rinda Check-mate who said I could borrow it. I just have to order the correct cables. I'm going to call Rinda tomorrow and see what cables are needed and if they know what can be viewed and controlled on my model engine.

[80Grady]

Another update:
Sent ECU to Brucato to be tested while their sale was going on. Just heard back that they found an injector driver that was bad.
What's the chances of this being my main problem. Hate to drop $1500 on an ACU to still be chasing this gremlin. I've had no luck finding another stock ECU to try and borrow to be sure thats the only problem. Whats your thoughts?

[OnPad]

Could very well be your problem. If it's bad you would be losing 2 cylinders and have symptoms comparable to yours.
I believe that any ecu dating back to the early 90's, with the correct fuel curve could be used as a replacement.

If you want to test the driver yourself you can use a noid light and a logic probe. I don't know alot about the stuff, but I guess that's how you test the injection control / wiring. I'm sure there's some other ways also, but like I said , no expert here.

Here's what the manual states, for driver test.

[PanRonnie]

there is a 200 ecu for sale in the part section for $ 325
might be a cheap fix
https://www.screamandfly.com/showthr...ercury-200-ECU

[80Grady]

I'm not really questioning Brucato's diagnosis, I'm just wondering the likelihood of this being my only problem. I guess I still don't have a good grasp on exactly how this fuel and ignition system operates. I guess my main concern is if there's multiple failed parts, in which case my problem may still exist. Or worse yet, another bad part which causes failure to other parts. I just don't want to be running in circles any longer chasing this. The only other component that's in the system that I can't find a test procedure on is the timing protection module. My one manual basically states that if my timing advances as it should, then the module is likely okay? I could see a faulty CDM causing my issues though too, but they all ohm out within spec. Anyone know of another test for the CDM's? Or somewhere to send them and have them load tested like the ECU? I'm willing to spend the money on a new ACU or any other necessary parts, I just don't want to randomly replace parts on a hunch, but have no problem spending whatever is needed to correct this problem. I also don't want to purchase an ECU to find that a bad TPM or CDM is damaging the ECU , if that's even possible.