wvamathteacher

I keep getting 0303 code #3cylinder misfire I pulled plugs and all 6 were clean antifreeze is clean put new plugs and coil pack bar on it 2 days later it pushed same 0303 code #3 cylinder misfire any idea what it might be haven't lost any antifreeze

Radi

Next thing to try is swapping the #3 injector with another to see if the problem follows the injector or stays put.
If #3 continues to misfire after swapping injectors, check the wiring from the PCM to #3 injector and do a compression and/or leakdown test.
A vacuum gauge might be interesting too, look for flutter in the readings which could indicate valve related issues.

Firestorm500

Look down the oil filler hole and see if you can see any cracks in the head between #3 and #4.

Roler

Fire, just curious; why does this misfire make you think of a cracked head issue?

bigbadon

That is one of the possible symptoms of a cracked head. Since the head most always cracks between cylinders 3&4 it will affect one or both cylinders. Are you losing coolant? Even a very small amount?

XJwonders

All 4.0 engines that were produced in 2000-2001 have a defective #0331 head, they are very sensitive to cracking between cylinders #3 and #4.

Has your engine overheated or came close to overheating in the past?

Roler

And a month later....how is this all going?

walwal63

The common crack happens on top of the head. It does not crack anywhere that would leak coolant into the combustion chamber. The coolant will go into the oil. So the common 0331 head crack will not make it miss.
I am curious to find out if you did fix the misfire as well.

HuntinXJ

Heat soak #3 injector? Happens to mine on occasion.

BlueRidgeMark

wvamathteacher. Hmmm. math teacher.

Teacher.


And in not one of his 6 total posts has he ever used any punctuation!






Oh, BTW, folks, his last post before this thread was 2009. I doubt he's going to get back to this thread any time soon.

Turbo X_J

01/08/2014

Firestorm500

Well he was a math teacher, not an English teacher, after all.

wvamathteacher

sorry took so long to get back on here working a lot it hasntmissed since the weather has been below 30 degrees outside ive bought a insulator sleeve for the injector haven't put it on yet. looks like its not a cracked head but the injector is boiling the fuel in the number 3 injector . thanks for the help and replys if the insulator works ill post

bigbadon

Not exactly true. A cracked 0331 head can allow coolant to enter the combustion chamber and cause a miss.

BlueRidgeMark

Before this thread.