350 MAG MPI No Start

"I have a 2000 Tige 22i with t

"I have a 2000 Tige 22i with the Mercruiser 350 MAG MPI (170 hrs). I've had an intermitant problem with this engine. After running in the water for varying amounts of time (once shut off) the engine won't restart. Cranks over fine. I first suspected water in the fuel - checked and nothing found. It did it again yesterday and this I had tools onboard and checked for spark at the coil. There wasn't any so I replaced coil. Engine fired up after a couple cranks and idled fine. Couple minutes later engine died at idle. Checked for spark on the new coil - none. Re-checked my grounding and tried again - still no spark. Tried again and zapped myself on the next crank. So I have an intermitant spark - any ideas. One other thing I noticed when replacing the coil. There are two wires (one white and one red) going to the terminals and the coil wire in the middle. A couple of inches away, on one of the wiring harnesses, is a black wire with a washer type connector on the end. This wire is zip tied back onto the harness. I haven't noticed any misses or anything, as the engine runs and pulls great, except for this issue. Should I start looking for gremlins????"

"Disconnect the battery and ch

"Disconnect the battery and check the computer connector for dirt, corrosion, etc. Make sure all your ignition electrical connections are clean and tight including engine and battery power and ground cables. Remove the tach gray wire from the neg. side of the coil and try running it w/o the tach. Sometimes they will screw up your electronics when they are dying."

"Thanks for the quick reply.

"Thanks for the quick reply. I'm assuming the computer is the box located near the passenger side manifold - marked E930. If so, no corrosion - everything appears to be clean and dry. Ignition electrical connections are clean and tight. Removed the white wire (neg. side of coil) - still no start and the engine is cold. Any other ideas?"

"Just a side note. I also pul

"Just a side note. I also pulled off the distributor cap to check it and the rotor. There appears to be build-up on the plug wire contact points. The end of the rotor is flat??? I thought they were usually rounded - like GM cars??? When I was checking the for spark, I was testing between the coil and the rotor. Any more help?"

Kelreed:

You have just foun

Kelreed:

You have just found your problem. Get a new cap and rotor. Replace ONE WIRE at a time. Good trouble shooting!

"Forget to ask:

I looked at

"Forget to ask:

I looked at a picture of the replacement rotor and the end is square. If yours is burned on the end, I'd replace it along with the cap and spark plugs. A new coil wire or a complete set of spark plug wires is a good measure of preventive maintenance after 7 years unless they have been changed in past few years. Keep us posted on what you get."