Hello and thanks in advance. I am on my 4th coil. The last one lasted four months. This is my third 244 and have never replaced a coil before. Any ideas why I keep burning them out?

Also is there a source to tell me based on the VIN what part numbers were on the original components of the car at build? I am the second owner of this California vehicle and want to make sure I have the correct ICU and ECU in the vehicle for the coil etc...

Further, is there a source that would tell me the resistances at all the pins of the engine and ignition harnesses?

Do a search for "ignition coil test". Consult the Volvo green manuals, available here https://ozvolvo.org/archive/, for resistances.

Interesting problem. As was mentioned, how are you diagnosing a bad coil?

Is your car supposed to have a ballast resistor or a resistance wire in the primary ignition circuit?

Do you have the correct distributor?

I would insert an ammeter ( on a high scale first, then lower it )in the feed to the coil to see if any current passes through the coil when the ignition is not on. A constant current, no matter its magnitude might warm the coil so that it gets too hot during engine operation, shortening the life of the coil.

Could the output of the coil have a relatively high resistance short to ground, causing higher current than normal.

Then I would observe how the current varies when the engine is turned over. This should, vary with no current when the points are open.

Then I would try the same experiment with the regular feed to the coil disconnected, and a wire directly from the battery. through the meter. Compare the results.

If this does not produce a difference, I would try both experiments when I cranked the engine over with a wrench.

Let us know what you have tried.

I would also open the engine wiring harnesses to see if anything funky is going on inside them. Didn't some 80s Volvos have engine wiring that deteriorated ?

I was told that my '88 GLE had a 240 motor in it - perhaps your car has a similar oddball construction.

Thank you for your responses. On many occasions the car has stopped running resulting on three occasions a tow to the nearest shop. The coil was tested by the shops and replaced. The ICU was swapped out on two of these occasions. The ECU also swapped out at the last occasion. The last time I was close to my trusted Volvo mechanic who took a known good lead attached to the coil and a weak spark was observed, swapped the coil out and the spark was bright and hot. Plugs good. Wires good. Distributor ??? It is an 87 so I suspect either the ignition or the engine harness. Will spend a little time with the multimeter before parting with the 600 for the new harnesses.

Thanks for the references for further research.

This car is a beautiful clean California dream. Hoping to get it running like she deserves

what brand is the replacement? i'd get a CORRECT used bosch coil before i'd use any other brand that's new. all the years i did volvo, i replaced 1 coil. it was an 89 240. at the time it was about 10 years old.

I agree that the coil is not the go-to for ignition problems for Volvo. Problem is, the thing is easy to swap. And when the issue disappears after the swap, only 1 tech in 20 will think about disturbed connections, and put the suspect coil back in to verify. So the coil gets swapped repeatedly and the connections never get fixed. Can't troubleshoot contact resistance in terminals by "ohming out" a wiring harness.
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Art Benstein near Baltimore

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Interesting.

What do you do to distinguish a good coil from one that has failed, exactly?

My quick reference parts catalog shows p/n 1346107 for the ICU, and p/n 1336137 for the coil.
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Art Benstein near Baltimore

Never test the depth of the water with both feet.