Hey folks,
Well.. I did it again. got another beat up old Volvo. This newest one is a '71 164, Maroon, maroon interior... 4 speed, O/D. Perfect beat up old car..

So, she'd not run in about 3 years, and the fuel in there is that old. Surprized it ran at all, but it does... and not bad at that. Drove home about 120 miles with no problems.. just a lot of knock and ping.

Yesterday afternoon though, coming home.. she just died. plenty of gas. Spark seemed weak. In the end, I fiddled with it about 10 minutes, but didn't do anything.. then she fired right up, and made it another 2 miles... died again. Again, weak spark. So I poured some cool water on the coil.. and she fired right up, and got the last 4 miles home without skipping a beat....

So, of course, I'm assuming it needs a coil. Not sure, but that's all I got to go on so far.

My question is.. after the water on the coil, the knock and ping was nearly gone, if not gone completely... Is it possible that a weak spark due to a bad, overheated coil could be the actual cause of the knock/ping/precombustion? Sorta seems like it could, sorta seems like it makes no sence...

It's good to be in a 164 again...
Thanks for insights

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-Matt I ♥ my ♂

Could be your alternator isn't properly grouonded (corroded wire, for wxample)

You might have traveled 120 miles on battery power

Install a new Bosch breaker point set and a condenser. After three years the contacts will be corroded.

I've got absolutely no science to back it up, but I've had similar experiences with weak\overheating\shortcircuiting coils. The issues I dealt with before involved "generic" coils, so I recently put a Flamethrower coil in and have had no problems whatsoever. The Flamethrower instead of a blue Bosch is almost definitely overkill in my stock setup, but I like it anyway.

Congrats on your new acquisition!

Did you have bad knock and ping that was solved by the coil? The coil in question is a no name aftermarket job... I've got a Bosch blue (known to be good), and all the ignition stuff is new. Guy couldn't get it started, and replaced the entire ignition system with new stuff recently.. new (yes, new) distributor, points, condensor, plugs, wires...

Of course, his no-start problem was the carbs.... so I got all these nifty new bits :-)

-Matt
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-Matt I ♥ my ♂

I can't say for certain that knock and ping disappeared only because of a new coil because I went ahead and switched out wires and went to a pointless distributor system at the same time. I can say that I was able to adjust the spark plugs .05 due to the fact that the coil was more powerful. Retrorockets has an interesting tech article concerning coils and how they affect engine performance. I'm pretty sure that Bosch blue will help do the trick. Best of luck!

OK.. thanks.

I wish I could for sure zero the no run situation to the coil for sure... Hate those problems that go away with basically nothing done by me...

But, first time it died... it sat for 10 minutes before starting.. maybe long enough for the coil to cool enough. Second time, was just a couple minutes, having poured the water on there... But I'll be bummed if I replace the coil and get stranded again... Oh well.. one way to find out I guess, and if I only drive up hill away from home... :-)

As for the comment about the charging system... it is fine. I picked the car up 120 miles from home, knowing I'd have to drive in rainy weather after dark. First thing I checked was that it was for sure charging...

I do find it a bit odd that it's got a Lucas voltage regulator... *sigh*... here I thought I was done with Lucas for a while...

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-Matt I ♥ my ♂

I did a little thumbing through my little library of repair manuals and can now conclude with certainty that your intuition concering a bad coil definitely "makes sense". Chilton's blames faulty coils from everything from poor power to misfiring to simply not starting at all. Do your spark plugs have the fluffy, black carbon deposits on them associated with weak ignition?

heh... right.. as if I've pulled the plugs to look at them :-)

Havn't had time to look at anything yet actually.. been a busy week. And I think the car might have lower ball joint issues (if not worn, maybe dry)... so that's priority numero uno...

I'll just pop in that new coil though and see how it runs... I'm curious still...





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-Matt I ♥ my ♂