I have a 96 SL2 twin cam with 84k, it was my dads and I cared for it after the dealer only serv of his first 30k, I have just (as maint) changed plugs, ff, and wires. The trans cover leaking for a while before I sealed it, and I did gunk it a little. Climate here is very mild 30 degree F at worst but it rains like heck here in winter.
At morn start up it has begun to chug and stall like on two cyls, if I stop, hold gas to floor, like to clear flood, it fires up, revs up, and clears up.
Then once warm she sings.

I put on two new BWD coils pairs last night with dielectric on conns.

Any advice, I brought the igniter/coil assm in for tonight to try warm on cold car to differ witch.

 

A common problem on this engine is a failure of the sensor(s) located on the drivers side of the engine cylinder head. Depending on the year one or two. They are used by the computor to read head temperurature thus an indicator for the heat gauge and to control fuel mixture when cold. Plenty of reference to them as to how many, what years they went from 2 to 1, how to identify them. Also that initially the factory installed the wrong calibration of them for many years. So where you get them was important.
General recomendation was the dealer.
There are no dealers any longer.
Aftermarket "should" have the correct ones at this point in time. If any at all!
If miss fire is the only code visible, then it is still a guess, if others, pay attention to them, may be part of problem. Also look for vacum leaks and sensors such as throttle postion and carboned up throttle body assemblys. Look in S series and tech support threads on this forum for posts related to those sensors.

 

These cars are much happier on stock parts

What kind of plugs did you use? no exotic plugs(platinum, etc) Stock NGKs please
Double check your wiring reconnection. Might even want to swap the old wires back in since you presumably had no misfire codes before them.

Stock coils, if defective, are more likely to throw a specific cyl misfire code if there is a problem.

Or it could be the ECTS as unc has suggested.

Just make sure you change only one thing at a time to keep the confusion down

My guess is plugs

 

@Derf,
What is the problem with Platinum plugs? It is just a metal change and I can't see a reason why that should affect anything. I'm not sure that Platinum (as I am writhing this at o-dark-30 in the AM getting ready to a swap meet and it is below freezing out there) isn't OEM. As long as you aren't doing anything silly like changing the gap setting and there is no reason why that should be done.
I use Champion as a plug of choice in everything I own no matter what came in the car.
Inquiring minds would like to know.,

 

waste spark ignition systems on the S cars don't seem to take kindly to the platinum plugs --- have read about many issues resolved by removing these and putting back stock. More an empirical observation from others' woes.

Now I have to do some real research on this

(Thanks Unc)

(someone feel free to post the answer and save me the trouble of looking it up)

 

A lot of times a platinum plug application will also have a larger plug gap. Two reasons for that would be that a higher voltage ignition system will fire a large gap and the material lasts almost forever. Well, upwards of 60 to 70 or higher hundred thousand miles. A number that favors smog criteria warrenty of 50,000 miles with no failures type of thing. If no one touches it you don't have to worry about it being futzed up. If a plug is in an extremely hard to get location you may find a multiple electrode platinum or other exotic plug again because with multiple electrode and high voltage ignition systems you can have a plug last a long time with out the need to change one.
BUT - If you pretty much have an ignition system that was designed for use with regular plugs and S series saturns probably fit into that early ones anyway, platinum was not a big seller than, they were available. Swapping in and out should not be a problem as long as gap is maintained. Increasing the gap will cause the ignition to try to generate more voltage than it was designed to do initially and I can see increased failure rates because of that. But as long as factory gap is maintained there should not be a problem. Same thing happened in the 70's when the switch from points to electronic ignitions than high voltage electronic, with increased gap. Spark plug wire size increased as did distributor cap diameter. If you tried to just change spark plug gap to a larger size because the new cars had that, wire cross fire, coil and cap failure and related problems.
I'm still running points on my 1970 street pony car and just located and bought a point distributor for my Chevy V8 I am building. Points work if you do not exceed the limitations of the basic ignition while using the engine. Just require routing maintanence.
My choice of plugs is persona preference. Not sure any of the competive alternatives are any better or worse.
Although there are plugs that are marketed with Bogus claims.

 

Quoting the venerable LowSaturn (and echoing the sentiments of many others who have gone to great length to describe the waste spark ignition system in our S series)
>>>
The issue with the Bosch platinum plugs (like many other Platinums) is because they have a tiny center electrode surrounded by a ceramic insulator. (Have a look, only the tiny silver center portion is the conductive platinum). Saturn "S" series fire their plugs TWICE each four stroke cycle, once at the compression stroke, and once at the exhaust (waste spark) When it fires in the exhaust stroke, it fires "backwards" requiring that tiny center electrode to recieve spark instead of emitting it. It's not up to the task, and misfires.

So they may function in the begining, but will quickly fail. And could cause damage to the coils and/or ignition module.
>>>>

 

@Derf, Fair enough on your research and description. My knowledge of physics says that the wire diameter is not a proplem although the spacing is.
The theory of operations is as follows in part anyway;

The secondary current always travels in the same direction and in a series type circuit. for example, when the PCM fires the ¼ coil, the current will flow out of he #1 coil tower, to the #1 sparkplug wire, to the #1 sparkplug, through the block, up through the #4spark plug, though the #4 spark plug wire, and back through the #4 coil tower. Of one of the plugs/wires were to open, he other mating cylinder would still fire out of is coil tower because the circuit would be completed through the E1 module bolts.

that would put two spark plugs in series, thus two gaps in series with the coil to generate the spark on two cylinders.
The voltage required to generate the spark is a function of two parameters, Gap and the contents between the gap. On the combustion side there would be high pressure + fuel. This would increase the voltage required to bridge the gap. On the opposite cylinder on the exhaust stroke, there would be no pressure thus the voltage required would be less. How much less comparing pressure vs no pressure, pressure as caused by compression. The theory of operation seems to indicate a 10/1 difference at least but I dunno. It makes sense to me anyway. Sensors actually measure the voltage spike and the direction of the spike when it is generated to fire the plug (s) which check and verify the codes.
No where can I find any data that indicates that electrode diameter is a factor. Just gap.
Might be. Dunno I guess, doesn’t gel with my understanding of physics. A non – platinum plug is recommended or stated differently a regular plug all the way through the run of the cars.
Don’t see any reason to not use a platinum, except for expense.
But
if it is reported to be problem prone, my gut says check the gap, if still a problem don’t use them.
But again. Nothing magic about standard NGK plugs, standard champions work fine. That is what I use.
RC12YC – Champions
This is kinda fun to compare notes this way.