2000 Malibu cylinder firing problem

I'm experiencing a firing problem in my 2000 Malibu. Cylinders #2 and #4 are not firing. The engine will run, but its very ragged. The car seems to run decently once the car is moving, but it has a problem when I accelerate from a stop. The check engine light is on and it will blink when I mash the gas pedal. It goes from blinking to a steady light when I let off the accelerator. There is a strong smell of gas when I have to stop. I had the codes pulled, and it came back as multiple cylinder missing/misfiring and a problem in one of the coil packs.

I've replaced the fuel filter, plugs, plug wires, 1 coil pack, and nothing has helped. I pulled the new plugs after driving it for a day or so and the #2 and #4 plugs had a strong unburned fuel smell. The other plugs were fine. I then tested each cylinder for firing by removing one plug wire at a time and the only problems were in the same 2 cylinders. I then pulled the plug and plug wires, one at a time, for the 2 cylinders (I put an old plug in place so as not to do any further damage). I left the plug wire connected at the coil pack and tested for firing and neither was getting any spark. One other item I found in the process has me a little (ok, a lot) puzzled. I checked the oil last week and it was a quart low, so I took care of that. Today, I check the oil again and I was amazed to find that the level was high. The level was about 3-4 quarts overfilled. I smelled the dipstick and it smelled strongly of gas. Is it possible to have gas leaking into the oil supply?

This leads me to believe that the problem is not in the fuel or exhaust system, but I am at a loss about what else to test/replace. Any help that you might have would be greatly appreciated.

You have cylinders 2 and 4 not firing.
To make a cylinder fire you need: air/fuel, compression, spark.
You tested negative for spark on both cylinders 2 and 4.
After replacing plugs and wires you can rule those out as suspect.
Going up the line you're looking at the new coilpack(the unit replaced supplies spark to 2 and 4, right?) I don't know how they wire these things, you're on your own with diagnostics here.
Check all connections between coilpack and ignition module.
I guess if the new coil pack checks out okay and it's connected correctly to the module, then you're tracing back to the module itself and it's power supply and grounds.

So much fun, man.. I bought one of these less than a year ago and I've been trying to sell it since the first week I had it. I'm goin' back to TFI in my Lincoln LSC. If these cars get any worse to diagnose then I'm walkin.

I hope something i offered helps. No big help, really.. just trying to put the pieces together with you.

Keep me posted.

-Mark T.

Could be fuel injectors too.Those are the new style that are a pain in the butt to remove.When a missfire happens,the certain fuel injectors that are the missfire ones do not spray fuel in when detected.

#2 and #4 are on different coil packs. From left to right

Coil Pack #1- Runs to #1 and #4 cylinders
Coil Pack #2- Runs to #3 and #6 cylinders
Coil Pack #3- Runs to #2 and #5 cylinders

I replaced the first coil pack after the code indicated a problem with it. Since then, I pulled the codes several more times with no recurring codes for any of the coil packs. The fact that each coil pack is delivering spark to at least one cylinder (coil pack #2 is working as it should), it leads me to believe that the problem is elsewhere.

As far as the fuel injectors, I know that gas is being delivered into the cylinder because a strong gas smell is present when the car is idling or stopped at a light. More importantly, I removed the 2 plugs and both smelled heavily of unburned gas and no evidence of firing was seen.

I'm more than a little frustrated at the moment and I'm at a loss right now. I know they have pet psychics, but do they have car engine psychics? Thanks for the help and if you can think of something else, please let me know. I'm an engineer, and not being to solve this is causing nightmares and my wife is tired of waking up at 2:00 in the morning and finding me rocking and crying in the corner because there seems to be no answer.

I left the plug wire connected at the coil pack and tested for firing and neither was getting any spark.


You need spark to ignite the fuel in those cylinders. If #2 and #4 have no spark, they won't fire. The first logical step from here is to obtain consistant spark at these plugs. Verify correct gap, try known good plugs. Check wire continuity and resistance.

From there I am stumped.

Assuming all replaced parts work properly, I suppose you might be looking at ignition module.. what else would affect spark? Who knows? I don't.

I'm curious. What kind of engineer are you? What work do you do?

-Mark T.