Volvo Penta AQ151B ignition problems

[C. Woodall]

I have recently bought a 1987 invader with an AQ151B with a 290 outdrive. I have replaced the plugs, plug wires, distrubitor cap, condensor, I had taken the boat to the lake on Saturday. The boat ran ok but i did not think it operated at optimum performance. I had figured it was due to last years fuel in the tank. I would drain the tank, but do not know what to do with the fuel. Anyways, it ran all day Saturday. I got home and noticed that the drive bellow was starting to dry rot. I replaced the bellow with a new one. after installation of the new bellow i went to trim the outdrive up and nothing happened. Got to looking at this problem and found that for some reason the 12VDC from the battery to the ignition switch was fused. From what i understand this is normally a non fused circuit. I began disconnecting the wires off the back of the iginition switch to find where the problem was. Found that the problem was associated with the purple wire going to the iginition coil. Removed the purple wire at the coil itself and tested for short. Did not exist. I ohmed across the + and - and it read open. I dont understand what happened between the time I loaded it back on the trailer and the time i got home. Also this coil says that it is a 12VDC but requires a resistor wire or external resistor. I have looked for this resistor, but all i have found was a resistor that went to case ground of my alternator to the + side of my coil. this appears to be a fairly new coil. Normally something happens for these coils to go bad.....correct? Do any of yall have any suggestions or ideas as to what went wrong?

Thanks in advance

~Chris~

 

[Don S]

Re: Volvo Penta AQ151B ignition problems

I have replaced the plugs, plug wires, distrubitor cap, condensor, I had taken the boat to the lake on Saturday. The boat ran ok but i did not think it operated at optimum performance.

Did you replace the points too? If you did, did you set the dwell then the timing?

Got to looking at this problem and found that for some reason the 12VDC from the battery to the ignition switch was fused. From what i understand this is normally a non fused circuit.

There is supposed to be a circuit breaker on the engine that supplies power to the instrument panel (ign. switch).

Removed the purple wire at the coil itself and tested for short. Did not exist.

From then on, I'm really not sure about your testing methods.
With everything hooked up, do you have power at the ignition switch on the big red wire. If you turn the key to the run position, do you have power to the terminal with the purple wire on it on the ignition switch. Then check at the coil and see if you have power to the + terminal on the coil.

 

[Robj]

Re: Volvo Penta AQ151B ignition problems

The easiest way to fix this is to throw out the points, condensor, and ballast resistor and replace with a Pertronix electronic ignition with the appropriate Pertronix coil. That is what I did and it works great.

Have a great day,

Rob.

 

[JAL51974]

Re: Volvo Penta AQ151B ignition problems

+1 for the Pertronix.

 

[C. Woodall]

Re: Volvo Penta AQ151B ignition problems

now i am not showing a short. there is 12VDC on the purple wire while the key is in run. but isnt that too much voltage. so yes i have 12VDC at the ignition coil

 

[C. Woodall]

Re: Volvo Penta AQ151B ignition problems

no i didnt replace the points just made sure that they were opening and closing. they were not, so i adjusted them so that they would open and close.. the gap is about a match book cover...i know thats not really accurate, but i will have to get me a gauge to set it properly.