No spark,,,No Reason???? Help!!

[tdsr1]

I have a Merc 3.0 with the DDIS ignition. Using the Clymer manual I ran thru the DDIS troubleshooting. The ignition amplifier checked out ok. The motion sensor checked out ok. The ignition coil pack resistance showed 2.8 ohms. The book says that it should be between 1.9 and 2.5, could this be just my meter being mis-calibrated, as I had a spare and when it was took from service, the engine was running fine, it's reading was the same?

I ran this engine prior to a half hour haul to the lake, when we got there, it wouldn't start. It hasn't started since. When I check the spark plugs for spark there is none. I cannot understand why. Any help would be greatly appreciated. Thanks in advance.

 

[Don S]

Re: No spark,,,No Reason???? Help!!

Do you have battery voltage at the purple wire going to the module?
Also check at the purple wire on the choke coil for power.

You do have the safety kill switch lanyard attached don't you?

What year is this engine?

 

[Don S]

Re: No spark,,,No Reason???? Help!!

This might help also.

 

[tdsr1]

Re: No spark,,,No Reason???? Help!!

Voltage at the module, voltage on purple wire at electric choke. lanyard safety switch has been eliminated.

Ran thru trouble shooting as in the chart. I replaced both coil and module even though readings showed they were fine. Still no spark.

Can you think of anything else? I even tried using a auto sparkplug wire to test for spark, in case all the wires went bad, no spark.

Thank you for suggestions so far!

 

[Don S]

Re: No spark,,,No Reason???? Help!!

Two things to try.
Disconnect the shift interrupt switch.
Disconnect the tach gray wire (at the tach)

Again, what year engine?

 

[tdsr1]

Re: No spark,,,No Reason???? Help!!

Sorry, The engine is a 1990.

 

[Don S]

Re: No spark,,,No Reason???? Help!!

Good news. With a 1990 engine, here is a real service manual.

http://www.boatfix.com/merc/Servmanl/13/13covr2.pdf

 

[tdsr1]

Re: No spark,,,No Reason???? Help!!

Don, I click the link that you gave me for the manual and it only gives me the front page. Am I doing something (else)wrong??

 

[tdsr1]

Re: No spark,,,No Reason???? Help!!

Don, never mind the last post, I needed to update my Adobe. Thank you for the link!

 

[ss9940_2]

Re: No spark,,,No Reason???? Help!!

Hi there!

Had a similar problem with my 3.0 Volvo, it's just a hint: The resistor wire coming from the EST module and going to the coil was bad - so hence no spark Try the wire out with an ohmmeter. My wire was working if you prickled with it, so the engine was working, then not working, then working again... it almost drove me crazy, especially one time when we were on a lake

As i said, it was just a suggestion Don is da real man...

 

[tdsr1]

Re: No spark,,,No Reason???? Help!!

I don't have an EST module. I checked all the connections and still cannot understand why there is no spark. I am sure I'm overlooking something, but I can't think of what.

Thanks to all for suggestions.

 

[Haut Medoc]

Re: No spark,,,No Reason???? Help!!

Have you looked at your shift interrupt switch to make sure it is not stuck?......​

 

[Danny80]

Re: No spark,,,No Reason???? Help!!

It sounds like we may have a similar problem. I don't know that I have a DDIS though - since mine is an 1988. I have checked and re-checked everything! But like you, I know that it is going to be something simple that I am overlooking.

 

[tdsr1]

Re: No spark,,,No Reason???? Help!!

The shift interrupter switch is on the valve cover, right. If so we checked it out and it appears to be functioning correctly. Just in case we have eliminated it and still no spark. Danny if you find something that is being overlooked please pass it on. From what I can tell we do have different systems, I technically do not have a distributor, I have a coil pack. Everything I check seems normal, but no spark going to the plugs. There has to be something that I'm missing, but for the life of me, I have no idea. I hauled it to the mechanic and he seems, for the moment, at a loss, also. That really gives me the warm fuzzy feeling!!!!!!!

 

[Don S]

Re: No spark,,,No Reason???? Help!!

Did you ever remove the gray wire from the tach and try it? I've seen more than one tach short out an ignition system.

 

[tdsr1]

Re: No spark,,,No Reason???? Help!!

Don. I had a problem with the tach last fall I fixed it, but just in case I disconnected it to see if that was the problem, still no spark. I am hoping that if the tach was the original problem, it didn't ruin my ignition amplifier (both of them).

 

[Don S]

Re: No spark,,,No Reason???? Help!!

Personally, I think you're ready for a new Ign. Amp. .............. But I didn't so the tests, so can't say for sure.

 

[tdsr1]

Re: No spark,,,No Reason???? Help!!

Don: that's what I'm worried about. like I said, I have tried both of the ones I have. the other worked last fall when we pulled the engine (cracked block from previous owner). I am really worried something burnt both of them up and would like to know what before we connect a new third one up!

 

[Don S]

Re: No spark,,,No Reason???? Help!!

Have you removed the cover of the motion sensor and cranked the engine and verified the shaft is turning?

 

[tdsr1]

Re: No spark,,,No Reason???? Help!!

yes we have, it turns.