Lil help needed, 2001 Optimax 225hp serial 0T272917 injecter#3 and ECM driver

[DaveH]

Hey guys,
Just got my engine diagnosed with a bad ECM, #3 fuel injector driver.
I sent The ECM in to Simon Performance, and it's been repaired, I'M awaiting the ECM in the mail.
There telling me to check injector #3 T wiring to make sure the problem doesn't come back.

I don't know what the 'T" is, I checked the wiring coming from the injector though the harness and it all looks good.
Prior to losing the ECM I had the battery die on me and had very low voltage.
I tried to restart, and the #3 injector was flooding everything with fuel, my voltage was at 11.08.
Could a dying battery have caused my ECM to go out?

So, I called the Gal in the office at Simon Performance Tech., and she had read the techs report wrong and said it was supposed to be just check wiring and the Teflon ring on the sealing ring on the connector.
As is there is no 'T" wiring.

[EuropeanAM]

Make sure there are no bare spots on the wires that indicate chafing against a ground. Glad they clarified the "T" that didn't exist.

[lpugh]

Ohm test the Injector at room temps and warmed to about 140 degrees. Do not overheat it. 1.7 to 1.9 ohms
If resistance is low it will damage the PCM
With PCM disconnected, check the orange white wire for shorts to power or grounds with key on

[EuropeanAM]

Also test resistance from each terminal to the metal body of the injector. Resistance values of less than 800 ohms can be problematic.

[DaveH]

As always, thank you for your knowledge and expertise.

[DaveH]

Update, I did the tests prior to running the new PCM, all checked out good and in range. I installed a new interstate with 1000 cca.
the motor fired up strong and after warming up taking off the motor sputtered rolling into the throttle, one time it even died, mid-range and top end ran great.
I'm thinking that due to the PCM flooding out the engine and all the oil loaded though the system that it needs ran to clear it out.
got back home and inspected the injectors for any blow by and looked good.
I pulled the plugs and noticed ground deposits on the electrode on couple of the plugs.
I'll warm it up on the muffs and pull the plugs and spray some mercury power tune in the cylinders.
Should I try and clean up the deposit on the electrodes and recap the spark plugs or just get new plugs?

[FeFanatic]

What's your definition of ground deposits? When in doubt replace the plugs. JMO.

[DaveH]

Part iridium tip has left a lil deposit on the electrode.
yes I'm replacing the plugs today.

[lpugh]

Part iridium tip has left a lil deposit on the electrode.
yes I'm replacing the plugs today.

Somewhat concerned about this, Do a compression test and inspect piston tops & cylinder walls with a borescope camera.
Good pics of the plugs would be useful.
Since you found no problems with the wiring, I would suggest that you replace that injector as it could have an intermittent short.

[DaveH]

Leon,
Took it to the lake Sunday to test with the new plugs and I'm still getting a stumble and it will die at times on take off , If I roll into getting on plane between 700 to 900 rpm it will stumble, but if I go full throttle no stumble. Other than that, its running really good.
I'll see if I can borrow a borescope and do a compression test.

[lpugh]

Leon,
Took it to the lake Sunday to test with the new plugs and I'm still getting a stumble and it will die at times on take off , If I roll into getting on plane between 700 to 900 rpm it will stumble, but if I go full throttle no stumble. Other than that, its running really good.
I'll see if I can borrow a borescope and do a compression test.

Symptom of a failing tps. Need to preform a sweep with scanner or DSO.

[EuropeanAM]

Also keep in mind that these engines aren't tuned for peak/smooth performance in that 700-1200 RPM range, as it's an area that results in "plowing" and an extremely wide range of engine loads depending on boat/prop configuration. Also a range that's seldom used as well.

One item that can exasperate this is a worn throttle cam ROLLER (flat-spotted), as well as TPS problems as Leon mentioned.

[DaveH]

Don, Is there a part number for that roller cam ? mine is worn down to inner plastic, no more black roller left.

[EuropeanAM]

858851A03 (have to replace the arm and roller as an assembly per Service Bulletin).