I am receiving the following codes:
p0300 - multiple misfire
p0301 - misfire cylinder 1
p0302 - misfire cylinder 2
no other codes.

After clearing the codes p0302 will always populate first and it wil be several minutes till the other two show up.

The engine runs rough at idle and will misfire at 1500rpm, and possible also hire rpm. I have replaced 2 coils / 8 plugs / tps sensor / iat sensor. No help.

What am I missing?


2002 4.7

 

What kind of spark plugs did you use and did you correctly gap them to .040"? Yes, it does make all the difference.

 

The same champions that came stock yes i gapped the .40

 

Do a compression test. If it is good my best guess would be the injectors. You might try injector cleaner in the tank but I haven't seen this work after they become dirty enought to set a code.

 

Start with the easiest first before jumping to a compression test.

Was that the only codes given were the misfire codes? If so, was it doing it prior to replacing the spark plugs. Just a silly thing, make sure the coil boots are firmly seated on the plug and all the ignition coils are hooked up properly.

 

Could be a Cam sensor or crank sensor. Unplug the negative battery cable before you replace either of them or you will blow the sensors! I'm leaning more toward the Cam.

Also could be bad gas, get a bottle of Seafoam and some new high octane fuel from a different location. I don't like additives, but Seafoam is one of the ONLY ones I will use.

 

It was the start of these issues that led me to replace the plugs.

I have of course confirmed wire connections on all coils, and swapped coils to see if the issue moves. It does not.

The only codes are those already listed.

I have run some seafoam in it this past week, no benefit. I often run Lucas treatment as well.

A friend loaned me his NOID kit last night. I installed it on cyl 1 and it ran fine for about 1 min then the light cut out. I installed it on cyl 6 and the light was constant. Tonight I will pull the Air box and access cyl 2, but I suspect it to is cutting out like cyl 1.

What common component would have them shut down?

 

Now when sitting at a light the check engine light flashes....

 

That's the PCM detecting a misfire.

 

Cant anyone help?

A friend loaned me his NOID kit last night. I installed it on cyl 1 and it ran fine for about 1 min then the light cut out. I installed it on cyl 6 and the light was constant. Tonight I will pull the Air box and access cyl 2, but I suspect it to is cutting out like cyl 1.

What common component would have them shut down?