Volvo AQ151B Ignition Issues

[CPAZ]

I Have an 88 Sun Runner with a Volvo AQ151B. I have replaced every part of the ignition other than the distributor which has been upgraded with a Hot Spark Ignition but am still running on 3 cylinders a majority of the time. So far Ive replaced plugs, wires, cap, rotor and coil with an MSD Blaster 3 and have rewired the ignition system. When it fires on all 4 the boat runs great!! Any info on what may be causing this issue is appreciated.

 

[bruceb58]

What makes you think it's running on 3 cylinders?

 

[CPAZ]

What makes you think it's running on 3 cylinders?

Lack of power and usually rough idle or hard to start. When I pull the plugs #3 looks brand new the others are tan like they should look.

 

[bruceb58]

You aren't going to like my suggestion!

Put the points back in!

Just for future reference, whenever I do a complete ignition overhaul like you did, I replace the sets of parts in stages in case I screw up. That way, it's easier to know what to look at when things aren't working properly. I know in your case that may not matter because sometimes it works ok. Just a little advice on what I do.

 

[CPAZ]

You aren't going to like my suggestion!

Put the points back in!

Just for future reference, whenever I do a complete ignition overhaul like you did, I replace the sets of parts in stages in case I screw up. That way, it's easier to know what to look at when things aren't working properly. I know in your case that may not matter because sometimes it works ok. Just a little advice on what I do.

It did the same thing before I replaced these parts and I did do it in stages. First I did the Hot Spark and rotor then I did the cap with plugs wires and coil. This thing should fire no problem since the ignition system is much better than the stock components. At this point I believe its something besides the ignition.

 

[bruceb58]

I actually believe in sticking with points as I don't like the reliability of these distributor upgrade systems. When points are adjusted properly, the upgrade systems are no better.