NEW PROBLEM! FLASHING CEL

Jeep Dawg · **Posted:** Tue Apr 14, 2009 10:49 am

Ok well this morning I have a new problem.
My CEL is flashing. I checked the error and I am getting a P0300 (RANDOM MISFIRE)
I replaced my plugs saturday along with my A/C compressor.

So I continued to drive to work and just as I got at my office, my KJ was running like CRAP and RPMS less than 1K. Engin spuddering then stall. I ran the error codes again and got the same P0300 then 06 and 05

I know I did the plugs correct. .040 gap on regular champs. my old plugs were normal wear.
Maybe I need to replace my coil packs now.

What do you guys think? COIL PACKS? Every thing is tight. I reconnected them when I got to work and still getting the CEL P0300 05 and 06

I got a qoute of 31.99 to 35.99 from napa and auto zone. They are price for EACH. Should I replace all 6 coils or should I just replace COIL 05 and 06 and see what happends next?

k99jk99j · **Posted:** Tue Apr 14, 2009 11:26 am

first switch the suspect coils with the good cylinders and see if the code moves! and its free! mike

Jeep Dawg · **Posted:** Tue Apr 14, 2009 11:30 am

k99jk99j wrote:

first switch the suspect coils with the good cylinders and see if the code moves! and its free! mike

Ya know man, I usally think of stuff like that. But not this time.
Thanks. I would have bought new ones and a week later I would have thought about the free option....HaHa

I am going to do that today after work. I am also going to inspect my wires for the coil packs to make sure mice did not damage them over the winter. I did find mice droppings on the engin when I replaced my Comp

adamkrz · **Posted:** Tue Apr 14, 2009 6:54 pm

I would check all the plugs again, I've seen one cracked plug cause all the problems you are now having including the flashing CEL,The coil packs seem to be quite reliable - You could also use an ohm meter to check each one.

tjkj2002 · **Posted:** Tue Apr 14, 2009 7:36 pm

1st you should have shut down the engine as soon as the MIL started flashing...........

Steady on MIL is okay to drive
Flashing MIL is a serious problem and engine damage has or is about to occur

You most likely had a rocker arm pop off,and then continuing to drive like that it could have popped more off.Unfortunately you have to pull a the valve covers to confirm it.

Jeep Dawg · **Posted:** Tue Apr 14, 2009 8:02 pm

tjkj2002 wrote:

1st you should have shut down the engine as soon as the MIL started flashing...........

Steady on MIL is okay to drive
Flashing MIL is a serious problem and engine damage has or is about to occur

You most likely had a rocker arm pop off,and then continuing to drive like that it could have popped more off.Unfortunately you have to pull a the valve covers to confirm it.

As soon as I saw the flashing CEl, I did limp it to work about 1 mile doing roughly 15 mph. The ride home was OK no CEL at all. I took 5 and 6 switched them to 1 and 2. So far no CEl it was only at idle. Tomorrow when I drive I will see if the P0305, 06 move to 1 and 2. (I HOPE IT DOES for my sake!!!!!!)
I checked all wires to coil packs and nothing looks like damage.
I also checked with a ohm meeter. I am getting res to all the coil packs.

ihatemybike · **Posted:** Tue Apr 14, 2009 11:24 pm

tjkj2002 wrote:

Steady on MIL is okay to drive
Flashing MIL is a serious problem and engine damage has or is about to occur

Don't really know if it's the same with the Jeeps, but in my vans flashing means that a current condition is causing a code to set. Steady on is just an indicator that a code condition has occurred. I've been driving around with a P0302 in Grumpy forever. After the engine is closed loop, anytime I let the van low idle the light starts flashing. When I get on the gas again it stops flashing. I can even clear the code and it won't return till I let it idle again.

Here's a list of causes for P030(1-8) Cylinder Misfire errors:
* Faulty spark plug or wire
* Faulty coil (pack)
* Faulty oxygen sensor(s)
* Faulty fuel injector
* Burned exhaust valve
* Faulty catalytic converter(s)
* Running out of fuel
* Poor compression
* Defective computer

When I had a P0301 in Green, I did the SeaFoam treatment and it cleared right up. Grumpy seems to have worse problems.

Sean · **Posted:** Wed Apr 15, 2009 10:09 am

based on the fact that you just replaced your spark plugs I don't think this applies to you, however I experienced the same issue, flashing MIL resulting from a misfire, and it turned out my PCM needed to be replaced.

Jeep Dawg · **Posted:** Wed Apr 15, 2009 2:44 pm

Well lastnight I pulled all the plugs and rechecked them for gapping. I am good .040
I moved 5 and 6 coil pack to 1 and 2

Today so far I drove 219 miles stop and go and no CEL stedy or flashing.

Maybe it was something loose or just gonna take time for the PCM to cycle again.

Jeep Dawg · **Posted:** Thu Apr 16, 2009 8:42 pm

So much for hope. My CEL came back and it still showes misfire on 5 and 6

Fuel injector? Rocker? bad wires?

tjkj2002 · **Posted:** Thu Apr 16, 2009 8:56 pm

Jeep Dawg wrote:

So much for hope. My CEL came back and it still showes misfire on 5 and 6

Fuel injector? Rocker? bad wires?

Couple of possibilities left...............

1-bad coil drivers in the PCM
2-Rocker problems,both cylinder banks
3-Carbon build up
4-Valve retainer problems
5-bad set of plugs

Can't really see coil packs being bad since the codes did not move when you switched the coils.I can give specific wires to check the coil drivers,just need a test light is all and at the same time it would be easy to check the OHM's in those wires to the coils to rule out wiring problems.

Albert · **Posted:** Fri Apr 17, 2009 2:04 am

Brian, you said you found mice droppings so you checked all the wireing real good for signs of chewing I am sure but check again in case you missed something. Just a thought.

Jeep Dawg · **Posted:** Fri Apr 17, 2009 8:35 am

tjkj2002 wrote:

Jeep Dawg wrote:

So much for hope. My CEL came back and it still showes misfire on 5 and 6

Fuel injector? Rocker? bad wires?

Couple of possibilities left...............

1-bad coil drivers in the PCM
2-Rocker problems,both cylinder banks
3-Carbon build up
4-Valve retainer problems
5-bad set of plugs

Can't really see coil packs being bad since the codes did not move when you switched the coils.I can give specific wires to check the coil drivers,just need a test light is all and at the same time it would be easy to check the OHM's in those wires to the coils to rule out wiring problems.

Troy that would be great if you could give me the wires to check. I have test lights and a very expensive Ohm meater. I use it for HVAC.
With the rocker (if it is that) how would I know if it is the problem

Guest · **Posted:** Fri Apr 17, 2009 11:49 am

Does it rattle?

Albert · **Posted:** Fri Apr 17, 2009 12:39 pm

Brian, if it is a rocker that is the problem then I don't see where the problem would be random. I would think it would run crappy all the time. It wouldn't break and run crappy, then fix itself and smoothe out, then, break and fix itself, etc. Plus one bad rocker on each side at the same time?

Just a thought. I am not a professional mechanic.

I am trying to do some research.

Jeep Dawg · **Posted:** Fri Apr 17, 2009 4:03 pm

Albert wrote:

Brian, if it is a rocker that is the problem then I don't see where the problem would be random. I would think it would run crappy all the time. It wouldn't break and run crappy, then fix itself and smoothe out, then, break and fix itself, etc. Plus one bad rocker on each side at the same time?

Just a thought. I am not a professional mechanic.

I am trying to do some research.

Yea that is what I cant understand...if it is a rocker issue then why is it not ALL THE TIME and now some times?

I am waiting for Troy's responce.

tjkj2002 · **Posted:** Fri Apr 17, 2009 8:33 pm

These are the driver wire color codes coming from the PCM to the respective coil/injector.

Coils.......

#1- Tan/Red
#2- Tan/Pink
#3- Tan/Orange
#4- Tan/Light Green
#5- Tan/Dark Green
#6- Tan/Light Blue

Injectors...........

#1- White/Dark Blue
#2- Tan
#3- Yellow/White
#4- Light Blue/Brown
#5- Gray
#6- Brown/Dark Blue

Simply back probe that wire at the coil/injector(with 12 volt rated test light),turn engine on and the test light should flash real fast,if not on at all check for proper back probe and ground(battery negitive post is best).If it is constantly on or does not flash real fast the driver is bad.

The wire codes above are for a '03 KJ,other years may be different,taken from the '03 FSM.

Jeep Dawg · **Posted:** Fri Apr 17, 2009 11:30 pm

tjkj2002 wrote:

These are the driver wire color codes coming from the PCM to the respective coil/injector.

Coils.......

#1- Tan/Red
#2- Tan/Pink
#3- Tan/Orange
#4- Tan/Light Green
#5- Tan/Dark Green
#6- Tan/Light Blue

Injectors...........

#1- White/Dark Blue
#2- Tan
#3- Yellow/White
#4- Light Blue/Brown
#5- Gray
#6- Brown/Dark Blue

Simply back probe that wire at the coil/injector(with 12 volt rated test light),turn engine on and the test light should flash real fast,if not on at all check for proper back probe and ground(battery negitive post is best).If it is constantly on or does not flash real fast the driver is bad.

The wire codes above are for a '03 KJ,other years may be different,taken from the '03 FSM.

Thank you Troy. I will give that a try on sunday. I am going to take my son to see thomas and friends at the beacon theater in NYC tomorrow. So I will give that a shot sunday and will report back with my out come..

Jeep Dawg · **Posted:** Sun Apr 19, 2009 5:17 pm

Troy,
I did what you said. My coils will flash real fast but injector is solid light ... I tested on 2 and 1 as well and received same solid light. maybe it is so fast I can not see it?

What else should I do. Wiring looks ok. mice did not get to it

tjkj2002 · **Posted:** Sun Apr 19, 2009 8:11 pm

Jeep Dawg wrote:

Troy,
I did what you said. My coils will flash real fast but injector is solid light ... I tested on 2 and 1 as well and received same solid light. maybe it is so fast I can not see it?

What else should I do. Wiring looks ok. mice did not get to it

Did you test any other injectors? If not test another injector 1st.If it flashes then you have a bad PCM.

NEW PROBLEM! FLASHING CEL

Who is online