2001 Discovery II, 70K.
Installed magnecor wires last year and new bosch +4 plugs if I remember correctly. Did most of the 60K mile recommended stuff.

Recently had a nasty leak at the timing chain cover, I took that entire thing apart, replaced the timing chain while I was in there. Truck ran fine, took it on 1000 mile trip, no problems.

Now I got a service engine soon light that occasionally flashes. Truck runs rough, especially under acceleration, going up hills etc. With the constant rough running, it now occurs to me that since the truck has been in the family that occasionally it would hesitate, a little hiccup if you will, where you could easily mistake the misfire as uneven terrain.

In any case, I thought it might be the O2 sensors causing this, but I had my buddy pull the codes and this is what we got:

P0300b
P0304b
P0307
P1300

I didn't write down the descriptions, but it was basically random misfires and the last code I think was manufacturer controlled ignition system.

He's calling it a coil pack that is dying. Just looking for opinions because at this point in my life I don't really have money to throw randomly trying to figure out this problem.

thanks.

 

P0300 Random/multiple cylinder misfire detected Excess emissions level of misfire on more than one
cylinder

P0304 Cylinder 4 misfire detected Excess emissions level of misfire detected on cylinder
No.4

P0307 Cylinder 7 misfire detected Excess emissions level of misfire detected on cylinder
No.7

P1300 Misfire detected sufficient to cause catalyst damage Catalyst damaging level of misfire on more than one cylinder

4 and 7 are on the same coil. Try to swap wires 8 and 7 and 4 and 5 to see if it the wires. Also pull those 2 plugs and see if they look OK. It just may be your coil though, used coils can be bought for fairly inexpensive.

 

just for laughs I'm going to try changing plugs. I've read elsewhere that the bosch +4's aren't the best bet, which is what I have in it right now. It's a cheap and quick way to test the problem...those plugs might be fouled...worst case I waste a few bucks and a few hours swapping out plugs only to have to do the coil later...we'll give it a shot though.

Thanks for the information

 

cylinder numbering?

P D
_______
0---0
0---0
0---0
0---0

FRONT

 

here you go...

 

I got excited because after I changed the plugs it was running flawlessly, check engine lights went out, no stutter, it was beautiful.

The next morning, she was running like crap again. On the other land rover forum a couple of folks wanted to scream head gasket, so I had my buddy run the chemical test for exhaust in the coolant and she came back alright.

We still figuring coil?

 

Put the Bosch back in and check your wires. When dark, start the engine, spray the engine with water, wiggle the wires and see if any of them spark.
Also, check the wire connection to the coil.

 

mike,

thanks for the feedback...dusk is kicking in now here.

I'm just wondering how common that coil failure is on these things? I'm running the magnecor wires so I wouldn't expect to have 2 bad wires in the set after only running them for a year but anything is possible. I'll do my best to put my hand between the block and the firewall and push the wires on the coil.

 

Coils do fail just not that common.

 

Got a similar problem, 99 D2 115k miles. Codes 1300, 300, 301, 305, 308. Magnecor's and +4's are only 6 months old. Went out one cold morning and to go to work and started having misfires. Got some cheap wires and Bosch copper plugs, have not put them in yet. I'm starting to wonder if the coil pack is going out. No loss of coolant, head gaskets done 3 years ago.

The misfire comes and goes, feels like it's only one cyl. at at time. I was suprised to find multiple misfire codes. It seems to run great when under moderate load and warm. Runs rough under light loads and cold.

Starting to think it's a coil, any ideas?

I'm going out to check all the connections when it gets dark out. Ideas anyone?

Thanks,
David