97 2.4L Bad idle Need enlightenment

[cybrmartian]

Happy New Year Everyone.

I have a 97 chevy cavalier 2.4L Twin cam that started idling badly intermittently every now and again in traffic the other night just after being started, what I mean by idling badly here is the RPM's would drop and come back up a couple times then idle normal again for about 3 minutes, but after going it started running fine again and No check engine light came on this time.

Yesterday (the day after the Above incedent) I was driving around town with no problem for about an hour stopping at a few diffrent stores and it felt like it started to sputter when taking off from a red light like a small miss and the check engine light came on so I went to autozone and got Code PO303 which is a misfire on cylinder 3. I changed the spark plugs yesterday and there is no diffrence I have been doing a lot of research and see suggestions of the coil packs. but do not know if these symptoms are what a bad coil pack would produce. Everything I see about coil pack failure is when the car runs fine until it gets up to temperature then shuts off which If I am correct in how I believe the system in this car works the problem I am having could be a coil pack. The way I understand how the coils in the car wark is that when one Cylinder is at TDC such as #1 @ TDC then # 3 would be as well on the Exhaust stroke and the same with #2 and #4. When each one is at TDC is recieve spark from the coil pack meaning that #1 and #3 are recieving spark but only the cylinder at TDC is using it and the other spark is wasted. so If one coild pack goes out then theoretically you should only be firing on 2 cylinders or am I mistaken?

That could be why I am here because I certaintly do not claim to be an expert and there are some in this fourum that are especially with these cars.
I do not have any extra money to just be throwing at parts right now that "May" be the cause so I am requesting any help that can be given.
What I have done so far is Change the plugs and checked the gap, Swapped current coil pack positions with no change in idle in that I mean I used the same coil packs that are in the car and did not put in new ones in hopes that maybe the opposing coild would be number one instead of 3 and maybe create a no-start situation instead of just a miss on number 3 that way I could definately help decide if I need to replace the coil pack but that test test does not rule out the fact I still may need to replace one. checked vacuum lines for leaks. the boots and rubber for the plugs are in great shape and were changed about a year ago and show no signs or wear, tears or anything. there is NO corrosion on the coil pack holder but there is a small hairline crack on one side that is not on any of the columns and does not appear to be in a critical spot.

Any help would be appreciated. If you need any more information I will give you everything I can get.

Matt

[cybrmartian]

Here is an Update. I got a coil pack and tried the new coil pack in both positions and there is no change in how the car runs so I am ruling out that it is a coil pack.

Does anyone have any guidence they can lend me?


Matt

[M1k3]

This is excatly whats happpening to me. i have a 1997 cavalier 2.4 also and it tries to stall when a leave a red light or from a stop. It pisses me off when i have chicks in the car lol makes it look like the car is a piece of shit. but anyways im still trying to find out what the problem is and if you find anything about it tell me and i will do the same.

Mike

[cybrmartian]

Mine does not do it with Chicks in the car. the car is still in the same place when I started having the problem. I do not want to drive it because the Check engine light begins blinking as you drive it and I do not want to damage anything else.

I am probably going to try to change the fuel filter this week and see if that could be the problem.

[16th hippy]

check spark, if spark is good, check fuel. if filter does't fix problem, get a fuel pressure gauge, and check pressure. I don't remember if the 2.4 has a fuel pressure regulator, but if it does, check that too. after driving it for a bit, remove spark plugs. your misfire is on #3, so focus on that plug. if plug end is whiteish in color, indicates a lean condition..meaning not enough fuel. would be a good idea to do compression check too since plugs are out. let us know what you find.

[cybrmartian]

Ok for an update I was able to get around changing the Fuel filter on the car today and had a few problems with the Quick disconnect not being so quick or convienent since the plastic part was not there at all. Changed the fuel filter and no change at all. Will check the spark tommorrow I do have Mac Fuel pressure test kit at my parents house which I will hopefully get this weekend or soon if spark is good. Any Specific test or way to test the Fuel pressure regulator on the 2.4 that you can suggest they list a Regulator as a part for this car through Autozone so I assume it has one but I will Double check that and will look through the Haynes Manual as well.

Matt

[kirkwood158]

had same problem.... but no chicks, came to find a vaccum leak in the bend of the hose that leads to map sensor and intake which did cause it to run rich and I also had the same codes. check all the vaccum lines yea and I did the coil thing too..... same motor and year

[M1k3]

so if i did that what kirkwood did my car should run fine after ?

[twuke31]

If your car smells like raw fuel or you pull the vaccum line off the fuel regulator and it smells like fuel in there then you need to replace it I had the same problems with mine about a month ago. The fuel regulator is on the left side of the motor at the end of your fuel rail.

[Thunderbolt2]

Did you ever get this resolved ?? I am having the same problem only it is cylinder number 1. I have been told it is the ignition module, but at $230.00 I want to be fairly sure. I also swapped coil packs and plugged the scanner back in. It still misfired on number one. Pulled the plugs and they look fine so I swapped the number one plug with another and still misfires on number one. I am thinking it must be either the coil pack cover, fuel injector or module. It was stumbling a little at idle and then started stumbling a little on the highway. Now it runs like complete garbage. The number one cylinder is the only one misfiring.

[yhandor]

You ever fix it mine runs like shit too, its hard to start, REAKS like gas, and idles like shit, i have tried everything....

[Spyder3K]

You know, this problem is starting to sound a little familiar to my problem in my thread, but I think I have more advanced crap with it. I can honestly say that I've had no problems with my car acting up when there's chicks in the car. But if the car wants me to get 'hitched', it can forget it for the time being! haha

Find my thread and see if you're going through something similar or not.

[302Z28]

My '97 2.2 had a misfire code several times - intermittently. I was told that a misfire code is generated when a cylinder fires out of sequence. I have no idea how the computer knows who's turn it is, but somehow it does. I replaced the wires and it ran great until it developed another problem unrelated to this. The wires come off the coil packs on the back of the motor in a single bundle. After many miles, the wires leak voltage from one wire to another and cause the misfire. If the 2.4 motor does not have wires, please disregard.
Thanks