Inconsistent No Spark, No Start

[WWMalibu2]

Hey everyone, I need some help diagnosing a weird problem.  I've gleaned tons of great info from this site that has saved my bacon more than once but I can't seem to find this issue...

2002 Sunsetter 5.7L.  I started having intermittent starting problems last season where we would ski or wakeboard for a while and then when I tried to start again, it would just crank but not turn over.  Usually if we waited for 10 minutes or so, I would be able to start.  Fuel pressure was great at key on and once it started pressure was within specs as well.  I run non-ethanol, premium.  I had issues with the ICM previously so I suspected it may be going out again (thanks TMC).  I also saw that people had issues with a bad coil that would then take out the ICM.  Over the winter I ordered (Amazon) a new coil and ICM and replaced both. 

First start up of the year was fine and ran well.  Took it to the river for the first time last week and on start up the key on oil switch beep continued while running.  Motor was running fine, oil pressure fine, and the wire to the switch was still solid so we continued on and I just thought I would need to get a new switch.  Stopped and ran three skiers and then it did the darn crank with no start again.  Waited for 5-10 mins and started it up.  Ran back up the river about two minutes and noticed the beeping had stopped this time at start up, then the motor died while running at about 35mph.  Engine cranked and cranked but didn't turn over.  I check fuel pressure, great.  Checked spark... nothing.  Since I had just replaced the coil and ICM, I did a quick swap of those two parts with the originals and she fired right up (thanks again TMC for the "go back to what you just did" advice).

Now, back at home the motor started right up but I still had a beep, this time a half beep with two quick beeps and a pause.  I shut off and tried starting again, crank but no start.  Pressure fine, no spark.  I did the paperclip trick (half paperclip in A and B terminals of the Data Link Connector) to get the ECM into diagnose mode and use a volt meter on continuity (with audible) plugged into the terminals E and F of the DLC (works great if you don't have a code reader or a 12volt LED handy). I got a code 41.  Resource says that is an ICM issue or possibly ECM.  I got another ICM at a local parts place and she started right up but again did not start after turning her off.  Again no spark. Again code 41.  Just for fun I put the old ICM (original) in and it started again but died with no spark after about 30 seconds.   

Now with the new (over the winter) coil and the original (prior to winter) ICM, I can start it repeatedly and I do not get the Code 41 but:

1. About every 4th try, no start, no spark.  Better, but still seems to be random.

2. I still have the dash beep when it is running

Thanks for any advice! 

Kevin

[Bozboat]

Do you have the old (original) style Kill switch where the plastic clip holds the red button down?

did you use the paste when installing the ICM?

Edited July 3, 2020 by Bozboat

[WWMalibu2]

Thanks Bozboat, the kill switch is 3 years old but I will check the connections just in case. Yes, I always use the heat paste. I learned that here! 

[WWMalibu2]

Okay so I was able to isolate the spark issue.  Testing yesterday I had no spark but started tracing all the way to the distributor and found that I had electricity all the way to the rotor, then nothing.  I had removed and inspected the cap and rotor probably more than a dozen times in the last year with the intermittent issue but never saw anything wrong.  They were only 3 years old with not a ton of hours and little to no corrosion.  Something must be wrong with the rotor itself to cause an intermittent issue because with a new cap and rotor, I was able to spend the afternoon on the water with no issues!  I'll have to inspect the old rotor a little more but there must be something partially detached or broken to cause an intermittent loss of spark.  

Moral of the story, don't assume a part isn't the issue just because it is relatively new and had worked in the past but be methodical and isolate each piece individually.  Hopefully this helps someone else on TMC!

Oh, and I picked up a new oil pressure switch with the cap and rotor, no more beeping... 
 

[funlife]

WWMalibu2- Sounds similar, and here was my issue....

 

Boat is back running. End result was a distributor rotor with the center contact that was completely fried, like completely gone - fried. Mechanic said he's never seen anything like that, especially under power, but concluded it may have been corrosion or a contaminant on either the rotor or distributor that worked its way to failure. (Cap and rotor was replaced two years ago). Amazing that it failed while under power, running about 3400 rpm (34.3MPH).  Anyway, glad that is was 'minor', and I'm back on the water in under a weeks downtime.

Certainly the "no start" checklist that 'justgary' has put together would have led to this as well. What amazes me is that there was ABSOLUTELY NO gas / fume / vapor smell when the boat shut down, not was there any upon trying to restart. - Thinking maybe that computer keeps fuel off/ pressure off is no spark/current is sensed??