Re: 3.0 OMC ignition problem
First off thank you all for the inputs. Unforuatally after all these tests i am still dead in the water. I ran it at night and didnt see spark jump. Did an ohm check from the base of the plugs to the block and recieved no resistance. Checked all four plugs with timing light and all are getting spark. Pulled all the plugs and tested the spark by grounding them to the block and all seem to have a strong/blue spark. Ohm checked all wires going from coil to dist. and main wiring harness and all checked good. The interrupt and overstroke switches have been disconnected this whole time. No water in the oil.
I also ran the vacuum test and no help. I closed the butterfly valve slowely and it never smoothed out just slowley died. I also poured water around carb to manifold, manifold to head, and head to block just to see if it would close the leak and smooth out for a second. NO GO!
Going after the timing gears. Process of elimination says its the only thing left.
As others said. try running at night and see if you can see spark jumping somewhere. Does a timing light on the wires (all 4) show it not sparking? Any water in the oil? Try grounding the spark plug for 1 and 2 and compare it to 3 and 4, do they look different (ie weaker)? You said with the plugs out you were getting spark on 1 and 2. Try also disconnecting the shift interrupt switch from the coil (long shot but vibration may be tweaking it). Are you getting a good ground to the engine block? Check resistance with an ohmmeter and such, check your ground cable to the block, check for a good ground at the spark plug holes. Check resistance with the plug in from the spark plug at the nut part to the coil.
First off thank you all for the inputs. Unforuatally after all these tests i am still dead in the water. I ran it at night and didnt see spark jump. Did an ohm check from the base of the plugs to the block and recieved no resistance. Checked all four plugs with timing light and all are getting spark. Pulled all the plugs and tested the spark by grounding them to the block and all seem to have a strong/blue spark. Ohm checked all wires going from coil to dist. and main wiring harness and all checked good. The interrupt and overstroke switches have been disconnected this whole time. No water in the oil.
Sounds a lot like a vacuum leak.
Here is a quick test since there is no place to hook up a vacuum gage on the 3.0L engine.
Remove the flame arrestor, and when idling slowly close the choke butterfly and see if the engine smooths out as it gets closed off. If it does, start looking at the base of the carb for a vacuum leak.
I also ran the vacuum test and no help. I closed the butterfly valve slowely and it never smoothed out just slowley died. I also poured water around carb to manifold, manifold to head, and head to block just to see if it would close the leak and smooth out for a second. NO GO!
Going after the timing gears. Process of elimination says its the only thing left.