Originally Posted by silver&gold
Well, yet ANOTHER issue came up with my wifes 2000 base 2.7 She called me and said that her check engine light came on and code P0303 came up (misfire detected on cylinder #3). I read another thread about possabilities on how to correct the situation, but need info as to location of things and how to do them. I cannot find my chiltons manual so I am lost.
*Where do I look for cylinders?
*Which one is #3?
*Can somebody PLEASE post a picture?
*Where exactly does the PCV valve sit on the 2.7? If it is the peice I am thinking of, it is leaking or seeping. I know I need to replace that.
I told her to try some injector cleaner as so many people answered it might be a clogged fuel injector. I will also turn the car on and check for leaks and sniff for gas tonight after I get up.
*Where exactly are the fuel injectors?
*Can they be isolated down to a certain one in order to unglog it?
*I plan on trying SEAFOAM, but where would the best place be to try and let it work on the injectors? Gas tank????
Plugs were changed about 4 months ago so they should still be okay right?
Most important question...Is she going to be safe driving the car until I can solve the issue? Please help.
^Cylinders are below the spark plugs( basically the plug screws into the top of the cylinder)
^#3 cylinder is the middle one on the passenger side
^PCV valve on 2.7 is screwed in to the top of the upper intake near the back,with a hose that connects it to the driver side valve cover...Probably not the cause of #3 cyl. misfire code , but never hurts to replace it..
^The fuel injectors are attached to a mounting rail and located under the upper intake plenum. They can be individually unplugged electrically to try to isolate a bad one --but this is really difficult to do with the plenum attached.. Also an injector performing bad enough to cause an individual cylinder misfire also will usually cause a slight bad idle..
^About the only way to get the Seafoam through the injectors ,without taking things apart or using other equipment will be to put it in the gas tank.,.Worth a try and it can't hurts to clean the fuel system occasionally anyway..
^Checking the condition of the #3 plug is where you need to start-- this will help you determine if the plug, coil, primary coil wire, etc is at fault.. Also will let you know if cylinder is rich or lean-maybe helping with the injector diagnosis..
^Probably not going to have any safety issues with her driving it with 1 cylinder misfireing..just wasting a little fuel $$$
ALSO might check:
Clear codes and see if it is an intermittant problem..
Pull wire off of coil with engine running, engine should miss noticably.. and then try swapping coils with another cylinder to check that coil,- code will change to another cylinder if that coil is bad..
Check for vacuum leaks aruond that cylinder's intake.
Lots of things can cause the misfire..(I think it has to misfire twice before it sets the code) i would clear the codes and if it comes back, start with taking a look at that plug, then check coil, then look for fuel issues, then vacuum leaks,compression problems,wiring faults, PCM etc.. Since the plugs and coils are so easy to get to it is a easy logical place to start..
Just my 2.7cents worth..