Would the ingition coils from a series II be better than the series I coils? would they bolt up to the bracket as well?

Someone on the board told me that a Delco coil from a 93 will bolt right up with no mods other that rerouting the plug wires.
I guess the bone yard is a good source for this complete unit and STB.

Hokey folks, there seems to be some confusion here. *MOST* of the Delco ignitions used on 3800s from 1991("L") to date are the same with one exception: The mounting plate.

The coils are the same as for many engines, the module (goes under the coils) is unique to the 3800, but there seem to be at least two different series of the mounting plate (goes under the module). The one that is interchangeable with the Magnavox ignition is pictured in the detailed posing in this thread but is just a flat plate with three captive bolts extending through the plate. The other series is "different" (have seen one that appears to have an alternator bracket as part of the plate & is not flat).

There is one pin that is not there in the connector (E). This for a seperate tachometer signal which is developed in the ECM so is not needed.

Ah, so that'* what that missing pin was for. That makes sense.

phoenix_flame220: As for the coils themselves, I believe that they are all exactly the same. Probably even the same part number. Not that it would be a bad thing to get newer coils with less miles on them.

SSEBONNE4EVA: Yes, if you get the coils, ICM, and metal plate setup from a '93 (or any NA Series I, for sure), it will bolt up just fine. But as mentioned above, you can also use coils from many different GM engines (mine were on a Lumina), and any '91 and up 3800 ICM. The only thing that changed is the metal plate with it'* captive bolts (in '95, from what I can tell, and also not sure about the SC engines at all).

Only thing is that only the OEM coils (not replacements) will have the nice while numbers on them.

I was also wondering this too. Would a Series II ICM be better then a Series I?. I don't just mean mileage wise, but is it a better ICM performance wise etc...or is it pretty much identical to a series I? Nice find on ebay. I'm keeping track of all of them so I can get the best deal.

ty

Someone who actually knows may correct me on this, but I don't think that the ICM has a brain, so to speak. I don't think that it makes any performance related decisions, but simply does what the PCM or whatever tells it to do. Therefore, what an ICM does when attached to a Series II may be different than the same ICM attached to a Series I.

Again, I could be wrong, but I think that the PCM, not the ICM, calls the shots there.

Oh, and Padgett is right about the nice white numbers on the stock units. If you get coils from anything but a 3800, your numbers might be wrong. Mine are all right, except that my "1" and "4" are reversed (both are on the same coil, in the wrong locations). It still works just fine, of course. Just go by what your haynes manual (or whatever) tells you about what wire goes where, not the coils themselves. And don't let other people install new wires on your car.

Or, if you're picky, scrape/sand/dremel off the old numbers, and carefully paint the right numbers on.

The ECU does call the shots.. so it doesn't really matter too much. I have an SII and SI ICM, and they are exactly the same. Both work just fine in my car. It'* just the bracket that doesn't. You could grab the ICM from any 91/92+ 3800 [not the LN3..]. The Coils could come from any car, but in '97 the SSEi got hotter coils, which are just about identical to those of MSD'* counterpart. So, you could pull the ICM and coils off any 97+ SSEi, and get better performance, than that of a 97+ N/A, or 91/92-96 */C. I hope that made sense...


-justin

ICM does have a brane just not a very big one. It takes the crank and cam sensor signals and turns that into a basic spark signal for each coil. It has total control up to about 400 rpm. After that the PCM/ECM asserts the "bypass" signal and begins to provide an offset (spark advance/retard) signal to the ICM to adjust the ignition timing according to the maps in the PROM.

So the ICM provides the basic spark signal and the PCM/ECM just tells it how far to advance or retard that based on the engine operating conditions.

The PCM/ECM does provide all of the commands to the fuel injectors based on the syntesis of the crank and can signals. (Both are required for sequential FI, if the crank sensor is lost, the engine will not start but if the cam sensor fails it reverts to firing all of the injectors at the same time).

For the engine to start, you must have spark, fuel pressure in the rail, and a signal from the PCM/ECM to fire the injectors. Three things instead of the two we used to look for.

The ignition module is unique to the geometry of the 3800 however beyond that "one size fits all" and so long as the crank and cam sensor signals do not change and the firing order and spacing stay the same, there is no need to change and the ignition module does not care if N/A or Boosted, the ECM/PCM takes care of the advance curve.

Can anyone else verify that the Series II SC had a hotter coil than their previous and NA counterparts? I had never heard that before, and so I question it.