Working on my neighbor'* '90 LeSabre. It has the Series I (square) coils.
It has been very hard to start in the cold. Once running, works fine. Starts OK warm. Has stalled a couple of times recently.
My first effort was to remove the throttle body to inspect the AIC pintle and passages. Throttle body was black with soot, no oil. Cleaned it and the MAF, and checked the resistances on the AIC. All OK.
Hard start cold persisted.
Checked coil resistances and got:
6-3........14.5 K ohm
2-5.........12.4 K ohm
Obviously I've got a bad coil. Can I swap in a series II ICM and coil pack? Will it just bolt and plug in? Or do I need to do something else?
Are those symptoms consistent with a bad coil? Once it starts, it runs normally without any apparent misfiring.