2003 Saturn Ion 3 misfire

[GLE3]

Hi All,

My son is having intermittent misfire issues with his ION. Only code stored seems to be P0300. Not sure if this is the right thing to do but we are replacing incrementally. Last weekend, it was spark plugs. This weekend, it's the ICM. Still have intermittent misfire. We got 100 bucks in the this now and I want to do my best to make the next part we install the one that fixes. So.. I have the gauge to do a compression test and I can get a fuel pressure tester loaned from Autozone. Any additional things I could do to hone the issue down before I sink more money?

Thanks!

[mcm485]

Originally Posted by GLE3

Hi All,

My son is having intermittent misfire issues with his ION. Only code stored seems to be P0300. Not sure if this is the right thing to do but we are replacing incrementally. Last weekend, it was spark plugs. This weekend, it's the ICM. Still have intermittent misfire. We got 100 bucks in the this now and I want to do my best to make the next part we install the one that fixes. So.. I have the gauge to do a compression test and I can get a fuel pressure tester loaned from Autozone. Any additional things I could do to hone the issue down before I sink more money?

Thanks!

Well, sounds like fuel since it's intermittent, but it could honestly be as simple as a bad wire/ground. Unfortunately you'll have to work each system until it goes away or you find the issue. Compression seems like the least likely problem, but should be checked.

Clean MAF, air filter, TB.. check for vacuum leaks/PCV cracked?... intake gaskets need to replace?

Fuel seems more likely, just hope you don't have a PZEV like me which has the fuel filter in the gas tank

Check fuel trims, O2's going would cause issues w/ car running out of whack or even the CAT if it got gunked up.

If it's still there and not in those systems, there's plenty of wiring and grounds related to these systems that could be deteriorating. After having some exhaust work done on mine the ground for the spark plugs (back right of engine) got whacked and needed to be fixed. This forum probably covers about every possible scenario at this point, you just have to put in the time searching the unique symptoms. Good luck!

[GLE3]

Thanks for the reply.. So what would lead you to likely fuel problem? The work we have already done? Are the chances slim it is the Coil pack? I know the code says multiple misfire, but couldn't that be because one coil pack and two cylinders... Like this guy?

https://www.youtube.com/watch?v=7PK6r3HbjkU

Originally Posted by mcm485

Well, sounds like fuel since it's intermittent, but it could honestly be as simple as a bad wire/ground. Unfortunately you'll have to work each system until it goes away or you find the issue. Compression seems like the least likely problem, but should be checked.

Clean MAF, air filter, TB.. check for vacuum leaks/PCV cracked?... intake gaskets need to replace?

Fuel seems more likely, just hope you don't have a PZEV like me which has the fuel filter in the gas tank

Check fuel trims, O2's going would cause issues w/ car running out of whack or even the CAT if it got gunked up.

If it's still there and not in those systems, there's plenty of wiring and grounds related to these systems that could be deteriorating. After having some exhaust work done on mine the ground for the spark plugs (back right of engine) got whacked and needed to be fixed. This forum probably covers about every possible scenario at this point, you just have to put in the time searching the unique symptoms. Good luck!

[GLE3]

Oh, well I guess the coil was good in the test in the video. I'll try the ohms test at the ICM port and see if it gets me anywhere...

[mcm485]

Originally Posted by GLE3

Oh, well I guess the coil was good in the test in the video. I'll try the ohms test at the ICM port and see if it gets me anywhere...

I have a BlueDriver obd tool which I would say is the bare minimum for troubleshooting random misfires because so much can cause this. I would watch misfire data to see what cylinders are misfiring and when. Chances aren't that it's a plug or coil without the occasional cylinder specific cel.

Low fuel pressure would affect random cylinders. Even a bad fuel injector itself would at least tell you which one. Checking fuel pressure at the Schrader should tell you a bit. There's several threads here about troubleshooting that stuff.

Keep in mind I listed a lot of other simple stuff like on the air side that could be causing this. You really should take some time going through the list and knocking things out in terms of regular maintenance. I've had two ions and they're very sensitive on the intake side for some reason.

[fdryer]

The majority of 2.2L engine misfiring stems from faulty ignition control modules (ICMl) if you search threads here or elsewhere on GMs 2.2L engines. The coil pack that generates high voltage spark fails intermittently. With all other issues being fine (fuel pressure, compression and spark plugs), I'm wondering if your coil pack is faulty. Rule out fuel pressure and compression before suspecting a faulty coil pack. As you know, the icm is the electronics side of the ignition system controlled by the pcm (as seen from the long winded but expertly done video) to trigger the coil pack into generating the high voltages needed for spark. The best part of that video is the advanced troubleshooting without having an expensive digital oscilloscope packaged into the expensive scan tool. Using pinouts and either a trouble light (presuming its 12v) or multimeter to measure resistance are two methods for diyers to follow for at home troubleshooting if an icm is suspect. The coil pack can be measured for input and output resistance too or for actual spark. A spark test would simply be connecting plugs outside the engine to coil pack with wiring connected to the icm and plug bases wired to engine block (ground). Pulling either the fuel pump fuse or pump relay stops fuel from being injected into cylinders during a spark test. Have someone turn the ignition key to START as you observe for spark across plugs.