Help with 2002 Mercury Optimax 225hp!!! PLEASE ANYONE.

[Spiny Rooster]

Correction, did check switch interrupter switch! Tried so much stuff almost forgot until I looked it up on parts list. Used the "OEM" loaner from Auto Zone which is why I question my results.

[Spiny Rooster]

By the way "OEM" is not original equipment manufacturer, it is the Chinese brand name (kind of sneaky huh?). Clearly not a Snap On product.

[XstreamVking]

Being that they were all close to the same does make it suspicious.....

[trex]

Have you checked condition of lower unit? I'd check compression again

[2jz]

Compression numbers are way to low but for all cylinders to be about the same is weird. Did you pull all the plugs out and have throttle wot that makes a difference. Also strong battery. What do your plugs look like how is motor burning fuel.

[Spiny Rooster]

Did take plugs out but did not push it to WOT. Dropped off keys at the mechanic a week ago still no sign of him showing. Guess I will be back at it next day off.

[Spiny Rooster]

Ok, mechanic was down yesterday unbeknownst to me. He says motor is mechanically sound, compression good. He says he believes a bad neutral or ground may be the issue. He is going to hook it up to the Rhinda software (laptop version) tomorrow to see what's up. Any suggestions?

[XstreamVking]

Pray.......

[Spiny Rooster]

Ok all talked to mechanic. Apparently it is definitely an electrical gremlin. For some reason the spark is not advancing as it should even on cold start. Suspects excluded:

plugs & wires new
tps through swap out
temp sensors new
thermostats new
crank position sensor through swap
interupter switch
ECM through swap out

Is there a sensor I am missing?

[Bullet89]

If the compression is only 65-70 psi, you have a big problem.

[2jz]

Pray.......

im no expert but how can your mechanic determine motor spark advance problem when ecm controls timin, no timing marks on motor to check with and you swapped with working one.
your compression test has to be wrong for one reason motor is still able to maintain rpms with other motor like you stated in earlier post. motor would run like crap with those numbers.
one thing you didnt try was coils and ignition module. I dont thing problem might be there because your problem is down low with rpm but its worth a try. four bolts and unplug coils and that whole plate with coils and ignition module can swap to other motor.

[flabum1017]

im no expert but how can your mechanic determine motor spark advance problem when ecm controls timin, no timing marks on motor to check with and you swapped with working one.
your compression test has to be wrong for one reason motor is still able to maintain rpms with other motor like you stated in earlier post. motor would run like crap with those numbers.
one thing you didnt try was coils and ignition module. I dont thing problem might be there because your problem is down low with rpm but its worth a try. four bolts and unplug coils and that whole plate with coils and ignition module can swap to other motor.

the ddt or rinda will show timing in live data......

[Zoomba]

Had a weird problem like that, found it by finding and marking flywhee with TDC for each cylinder, and label number for each cylinder.
Then using timing light on each plug wire to make sure each one firing at correct time. Eventually found a visibly burned pin on a cdm plug to coil connection. Ran fine at idle, but at 3000 the #4 cylinder timing began to jump around and kill the other cylinders timing. The engine was bought cheap because no one could fix it. Put on your reading glasses and remove each CDM connector and visually inspect. I think you have a harness or connector that is bad. Mine was the ground pin, one of the 4 pin sockets was visibly black and burned. Caused weird advance problems for months, Stan Carson told me to " index the flywheel" and that was the answer.
Changed 4 pin connector plug 2 years ago and a great engine now!




QUOTE=Spiny Rooster;2784904]Ok all talked to mechanic. Apparently it is definitely an electrical gremlin. For some reason the spark is not advancing as it should even on cold start. Suspects excluded:

plugs & wires new
tps through swap out
temp sensors new
thermostats new
crank position sensor through swap
interupter switch
ECM through swap out

Is there a sensor I am missing?[/QUOTE]

[Spiny Rooster]

Ok Screamers one more gremlin slain. Took the direct injectors to South Bay Injectors in Rockville Center NY. Frank, the owner who hooked me up when I had direct injectors throwing faults on the other motor hooked me up again!!!! Found one direct injector that was NOT THROWING A FAULT however was DISCERNIBLY STUCK OPEN! Now she runs and moves through the the RPM range smoothly above idle.

Idle is still a little rough, some stumbling, some surging but no stalling, the deviation is about 100 RPM at it's worst and very intermittent. I have also noticed playing with the trim while it stumbles has a sooting effect flatening the rough idle. In addition, she is charging up a half to 1 volt short of the good motor down as low as 12. So again I am speculating electrical. Any ideas ladies and gents?

BTW guys I am a die hard fisherman, I notice most of you guys are race boat guys and gals. I have a new found appreciation and respect for those of you in the motor sports (which I could never quite get my head around) but your active participation in helping me solve my problems has earned my respect and then some.

[XstreamVking]

Opti's should show at least 13.5 volts when charging. You prob have an alternator not putting out proper/consistent voltage that's screwing with the elec sensors. When the batts are in tip top charged condition, w/o any draw on the system from an electrical load it should read 14 volts.