1990 OMC Cobra 4.3 intermitant crank, no

[candiaoh]

I have a 1990 OMC Cobra 4.3 with an intermiant crank, no start issue. It started early in the summer and the problem was corrected by moving the shift in and out of gear once or twice before starting. When the problem occurs, the engine is getting gas, but it appears their is not spark/ignition. But by moving the shifter in and out of gear once or twice, the problem is solved, temporaily.

The last time this happend I was on the ramp. The boat started up just fine and I was letting it idle a minute to warm-up. The engine then stalled out and I was unable to start it again. Again, I verified it was getting gas in the carb. This time no amount of toying with the shifter helped.

I was thinking some sort of safety switch related to the shifter. I quick tested the neutral safety switch by trying to start it in gear and it did not even try and turn over, so I am thinking that is not the problem.

Could it be an ESA issue? Could a faulty ESA interrupt the ignition even if it is not engaged? I had the shift cable and bellows done last summer and I was thinking maybe the shift cable was not adjusted properly? I suppose it could be related to the ingition on the engine- coil, points, etc, but considering the shifter issue, I kind of doubt that.

Any thoughts are appreciated.

 

[alldodge]

The interrupter can keep the motor from firing, it can also be the kill switch (man overboard). Turn the key to start and hold it there, then wiggle the shifter back and forth, if it fires up, then might be the interrupter. If that is no help check for 12V at the coil. If no 12V start tracing back to see if the kill switch, key switch or something else has a bad connection.

 

[bruceb58]

When you say "no crank" does that mean the starter is not operating? That's what it typically means.

If you really mean "no start", you can unplug the ESA connector to make sure its not the ESA causing your issue.

You can also make sure the shift switch is centered in its detent on the "W" shaped cam on the shift plate back at the engine.

 

[candiaoh]

Thanks. When it acts up, the engine cranks, just doesnt start. The esa switch looks like its sitting in its place, meaning, it does not appear to be activated. That's why I was wondering if the switch went bad, would the engine just not start (but turn over)?

 

[bruceb58]

The switch could go bad but it's failure mode would likely be the reverse in that it wouldn't close.

You can:

1) Unplug ESA and see if it starts.
2) Turn ignition on and see if you have voltage at coil.

 

[candiaoh]

I was thinking the same thing...maybe I will look at the kill switch next. The problem is, its intermittant. I could back it up on the ramp today and it would run just fine, then tomorrow, not start.

Frustrating!