No Spark - 4.3 Liter Mercruisers

Hi all,

I have a 280 Sundancer.

Both engines have the same problem. They crank fine, and getting fuel - but no spark.

Is there a separate circuit for the coil? Different than the starting circuit?

I recently replaced some breakers and pulled all of the batteries, could I have left a wire or two off? I thoroughly checked but don't see any.

I also put a jumper from the battery to the coil but no difference.

Any advice?

Thanks, Mark

 

Thanks. So power is a separate circuit for the ECM? I tried going to this site, but I can't figure out which one is the wiring diagram, there are many, many links...I tried one and it took me down a rabbit hole. Might not help anyway as I am not great at reading schematics.

Do you know if there is a way to jump power to the ECM?

Just prior to this happening, I replaced many of the original Searay breakers on the main panel, I am wondering if I missed a wire? I looked closely yesterday and don't see any that aren't attached. I also pulled all of the batteries, thought maybe I missed reattaching a wire but that doesn't make sense as anything going to the ECM would have to be on a breaker.

Also, this is happening to both engines, so unless the same power goes to both ECMs, there must be two wires not connected.

I really appreciate your input!

 

Thanks, I will check that today.

 

Thanks for pointing out the link. I was able to download it.

It is a 2001 Sundancer.

There is a breaker for the ignition. One of the breakers I replaced. I believe it is the same breaker that powers the starter (from memory). Maybe there was another lead on it that I didn't reconnect, but if there was, I sure can't find it. I wish I had fired up the engines after replacing the breakers to test, but I didn't.

 

Yesterday I thoroughly checked the batteries, to see if something has become disconnected. All was fine. Took the opportunity to clean up everything and treat all of the poles with CorrisionX.

I don't seem to have the blade fuses behind he distributor and I don't see a 50 amp on top of the engine (scolaw).

On the main panel there is a breaker for each ignition, when off, the starter does not crank.

 

Thanks, so that is a circuit breaker for the ECM?

 

Update. Thanks for the input. I got them both started. While troubleshooting, I decided to clean everything up, including the battery terminals. And then charged all night. Guess what, they both started. Ugh...sometimes it is the simple stuff.

Now I have another problem, the port engine is running rough and will die at idle. I am getting some vapor coming out of the throttle body. My mechanic thinks it is getting too much fuel. The good news is that he is coming today.