Ok, my brother in law has a 2002 Saturn SL1 with the 1.9L I4 SOHC. Driveability sucks, it is definitely missing. The guys down at Saturn tell him that he has a bad fuel injector. I bring the car in, and the first thing I do is start pulling the wires to find out which cylinder is mis-firing. when I pull #2 wire nothing changes, so I was figuring it was the #2 fuel injector, but for the sake of it I decide I am going to see what kind of spark I am getting from the wire. Low and behold, there is almost nothing, just an occasional spark that is REALLY weak.
Ok, I figure it is the ignition contol module (ICM), so I take that to the local AutoZone to have it tested. On this control module, it has two coils that can be seperated. So they test the ICM and each of the two coils. Everything checks out. So, we get a set of wires and replace them, to no avail. #2 is still giving a very weak fire. To add insult to injury I am not sure if the coil that was originally used for #2 was the same one, during testing they could have been switched.

Any ideas on what it could be, my next step at present is to switch the two coils and see what I get.

Any update on this one? I have heard of others having issues with sputter and have not seen anyone with an answer.

Ok, my brother in law has a 2002 Saturn SL1 with the 1.9L I4 SOHC. Driveability sucks, it is definitely missing. The guys down at Saturn tell him that he has a bad fuel injector. I bring the car in, and the first thing I do is start pulling the wires to find out which cylinder is mis-firing. when I pull #2 wire nothing changes, so I was figuring it was the #2 fuel injector, but for the sake of it I decide I am going to see what kind of spark I am getting from the wire. Low and behold, there is almost nothing, just an occasional spark that is REALLY weak.
Ok, I figure it is the ignition contol module (ICM), so I take that to the local AutoZone to have it tested. On this control module, it has two coils that can be seperated. So they test the ICM and each of the two coils. Everything checks out. So, we get a set of wires and replace them, to no avail. #2 is still giving a very weak fire. To add insult to injury I am not sure if the coil that was originally used for #2 was the same one, during testing they could have been switched.

Any ideas on what it could be, my next step at present is to switch the two coils and see what I get.

i posted a video on checking the CPS (crankshaft position sensor) on another thread. ehh ill be nice and here it is again :)

http://www.youtube.com/watch?v=pUMGFnK29B8

video thanks to Richpin!

if your car behaves exactly like the video then the ignition system is not your issue. you may need new wires/plugs (copper not platinum). You can also try switching injectors from another cylinder to see if it really is an injector