'04 Merc 4.3: No spark

[Barry5292]

Hello,
I have a 2004 Merc 4.3 V6 (carberated). It has been working fine, but now I have a problem. The starter cranks the motor, but it won't turn over. There is good gas in it and the motor seems to be getting gas fine. I tried to see if I had spark at one of the plugs and it appears that I do not. I'd like to troubleshoot this and figure out what's up, but I don't know where to start testing voltages, etc. Any suggestions for a starting place? Thanks!

 

[Haut Medoc]

Re: '04 Merc 4.3: No spark

Read this post.....
http://forums.iboats.com/showthread.php?t=167035&highlight=starter+test
Make sure your kill lanyard is plugged in as well......​

 

[Barry5292]

Re: '04 Merc 4.3: No spark

Hello, Thanks for your help and the link. That is good info, but I think my problem is a bit different. I know I have a starter problem. I get a solenoid click, and if I tap the starter I can get a crank, so I know starter needs repair.

The main problem I want to troubleshoot is when the starter DOES crank, I do not see a spark at the plug. I have removed the wire off the plug, but a screw drive to the wire, and (while holding the insulated handle of the screw driver), crank the engine. The engine cranks, but I do not see a spark from the wire when I hold it close to the engine block (using it as the ground). So I believe that I need to start working my way to the distributer, coil, and whatever else might be the cause. This is where I could use troubleshooting advise similar to the key, solenoid, starter info you pointed me to.

Thanks!

 

[Haut Medoc]

Re: '04 Merc 4.3: No spark

Ok, Well, the first thing you need to test is if you are getting 12v at the + side of the coil with the key in the 'run' position....​

 

[Barry5292]

Re: '04 Merc 4.3: No spark

OK, I'll start there. I appreciate all helpful advise.
Thanks

 

[Haut Medoc]

Re: '04 Merc 4.3: No spark

This is what you need?......​

 

[Barry5292]

Re: '04 Merc 4.3: No spark

Thanks for finding this for me. I'm going to have to get some diagrams to identify all the parts that they mention...hopefully I can reach them also. Some of this stuff may be over my head to identify, but I'll give it a shot this weekend. Thank you again for you help!!