Misfire code any help here?

Hello I have a 99 grand am 2.4l and the other day it sounded like crap. So I decided to look at the plugs. They were slightly worn so I decided to change them. I went and got 4 new Platinum 2's and threw them in. It still ran like crap so I drove it to Autozone to get the codes read. Sorry I forgot to say that The check engine light and trac off light also were on. They said misfire code P0301 I think that was the number. Misfire for #1 plug. So I went and bought some new boots and swapped spark plugs to different positions. Reinstalled everything and still Misfiring #1 plug. So I thought maybe it was a fuel problem so I Took the fuel injector system apart and looked at them. They seemed fine and I reinstalled them.

Now there is no distributer "per say" is the spark plug cover the distributer and is this the cause of my problem? Also anyone know how much that thing is and what it is called?

Thanks in advance.

Welcome to AF.

The plate on top is the Ignition control module(ICM) and the coils where the boots connect.

I'd say get the ICM tested or replace it.
Might check the coils too.

Yup thx for the help. I found out that there is more components under that cover so I replaced them all:2 coils and the ignition module(aka the distributer cap). Now I gotta work on this low idle problem and shaking. I changed the idle control sensor and now I am going to clean the throttle body.

Thx for the help.......

the IAC does sometimes need calibrated when you replace it.
Might check this out if you havnt already. :thumbsup:

Idle Air Control(IAC) Testing Replacing for 99+ (http://www.automotiveforums.com/vbulletin/showthread.php?t=663849)

Hey guys I am bringing this back because I still have not figured out why it still shakes at idle. Running 10+ mph it drives like a dream. Only when I stop does it act up.

Here is what I have done so far:
Replaced spark plugs
replaced spark plug boots
replaced both coils
replaced plastic holder of the coils(sorry don't know what it is called)
replaced the IAC sensor on the throttlebody
Checked the injectors and they were fine
Thoroughly cleaned the TB and the IAC port.

I went through and read the adjustment of the IAC and the one I got does not seem adjustable the "cone" on the end did not seem like you could position it any certain way. It did move in and out but that is what it is supposed to do. I did verify the lenght was not more then....1 1/8 inches I think that's what it said in the article.

Now I have been doing some troubleshooting on my own, and If you disconnect the IAC at idle shouldn't something happen to your RPM's?

I do notice that the Shake gets worse the more you load the car...Turn on AC, Push the breaks, Turn the steering wheel, and the idle stays at 500-550. Never more never less.

Is there a way to check for voltage or signal to the IAC which could tell me that the ECM is bad?

Please help....

Yeah that link above should telll exactly how to test the IAC for voltage and whether its working or not.

You can damage the IAC if you move it the wrong way or are rough with it, like dropping it.

Thanks for the reply. It is very interesting that at cold temps the idle is good...around 900-1000 rpms. Which is telling me that the IAC is opening and allowing more air to come in until it warms up. I guess the problem is is when it warms up, the rpms drop to 500 or so and the shaking begins.

Is 500-550 too low?

Is there a voltage coming off the PCM to drive the IAC?

Can I disconnect the IAC for good and run it at "cold" setting and not hurt the car?

I am just asking because I hate to make that 200$ mistake by buying a PCM or ECM and it not fix it. Going to a dealer to fix this could end up costing me 400-500$. I only paid 800 for the car and it is a very nice car.

I didn't mention but the lights went out after I changed all the Ignition components. Only the shaking remains.

Thanks again for the help.

***Update***

Ok I got the haynes manual and did some more troubleshooting.

As I figured the IAC is working right. I removed it from the throttlebody, and pushed the cone in ever so slightly. I disconnected the connector and started the engine. RPM's went to about 2000. I connected the connector and let it sit there for about 20 seconds then put it in drive. The RPM's slowly dropped to 500-550 and the shaking bagan again. Does that mean that the ICM is working too and something else is giving it information to run that low?

Thanks again.

If you had your motor running and you connected or disconnected the IAC then you probly will get a DTC stored.

Idle is around 550-650 RMPs, what you might have is a busted motor or trans mount causing your shaking.

Might not hurt to get the thing scanned with a high quality scan tool to see if anything else is going on.

And as I said before, this link tells you how to properly disgnose your Iac.
http://www.automotiveforums.com/vbulletin/showthread.php?t=663849
Good Luck!

Replace the plugs with AC delco's, anything but Bosch. I had the exact same problem with my grand am and i spent a couple hundred dollars changing parts before finally finding out Bosch makes cheap plugs. Good luck.