1999 502 Mag - no spark
 

Friend has a 1999 502 Mag with no spark. Problem started intermittently and would lose power(bog, miss, pop, etc) for 1-2 minutes every 15-20 minutes of run time. But, ran perfect during those 15-20 minutes. Replace the ignition module and coil and still did it. Last time it lost power it died and now no spark and it appears the injectors aren't opening as plugs are dry after cranking it. It's my understanding the pick up coil communicates with the ecm so both spark and injectors can quit. So we replaced the pick up coil in the distributor and still dead.

We have power to the red wire at the coil, the pink wire coming out of the coil and the pink wire going into the ignition module. Ohms between green and white wire on the pick up coil are in spec. But no spark coming out of the coil. I am thinking maybe the ecm or possibly something in the distributor isn't allowing the pick up coil to communicate with the ecm(or wiring between the two).

We also unhooked the tach to make sure it wasn't grounding the coil.

Stumped.

Just a follow up it was the distributor. Picked up a new one, plugged it in at the ignition module(didn't install it) and spun the gear. Got spark and the fuel pump kicked on. Installed it and fired right up! Figured I would post the solution in case someone searches this topic.

Thanks for posting the solution.

Ken

There is a good flow chart in Merc Manual #16 for the next time you have these problems. It will steer you right in to which component is fried.

Where did you pick up a distributor at?

That might be my issue. I have an intermittent miss/pop above 2500 RPMS after 30-40 minutes of run time. I think mine is more heat related as I have completely ruled out the fuel/pressure issues.

Would the problem only manifest itself after a long run time? What about codes? Did is throw any?

http://www.offshoreonly.com/forums/g...-run-time.html

We had a service manual(non-merc) that had an order of components to check. But, it stated the coil, ignition module or pick up coil were the 3 that would cause no spark at the coil. The distributor was only mentioned when there was spark at the coil and not at the plugs. Which is why we were stumped. We were told by a few people the distributor couldn't cause no spark at the coil. They were wrong.

His didn't throw any codes. It was cutting out and losing power for about 1-2 minutes after 15-20 minutes of running fine. Then run fine again for another 10-15 minutes. Over and over. He replaced the coil and ignition module and it still did it. Then it cut out and totally died with no spark. He then replaced the pick up coil and still no spark. Then we did the distributor. He got a reman at an auto parts store.

http://www.autozone.com/autozone/par...ier=15408_0_0_

Thank you for that info. I am at the point of throwing parts at it. Or at least swapping parts until I can get the problem to move from the port engine to the starboard.

So the part number he used was DC804EFI

I HATE buying merc stuff at 1000% mark up. I might just paint my **** blue to make it worth more $$$$!!!

I hear ya! He used the 30-1830 part number at a local auto parts store. $92 with exchange.