Do you have spark on cylinders 1 and/or 7? I would check that first before going through the trouble of swapping coils. They're kind of a bitch to get to.
Also, if you don't have spark, don't run it much. You can damage your catalytic converters. That will cost you tons more money and it's totally avoidable.
Keep in mind too, not all misfire monitors are 100% accurate. They're pretty good, but not perfect. I have seen an engine with a #3 misfire code, but only a misfire on cylinder #1. It wasn't a Rover, but I'm sure it could happen on one of these too.

 

hi thanks got them swapped cleaned etched and did valve covers and gaskets rebuilt all wire harness sheathing replaced wires with 8mm ones i had were napa replacing water pump and lower hoses general cleaning feeling good plugs i had i couldnt find the number for they were bosch and the same reach and platinumand i was assured they were the same but wrong plug can throw a misfire code i read i had a noticeable skip.....all this stuff was due anyway!!!!

 

here is my favorite[IMG]498jpg[/IMG]

 

He's already getting P1300 indicating possible Cat damaging misfire.

As 'disc oh no' says, are you sure you are getting a spark at all the plugs. If you are at least you know the coils are OK.

Then check you have all the leads in the correct place, going to the right plugs. All to easy to get a couple in the wrong place causing the misfire. I know as I did it myself and a check of all the connections sorted it out when the 2 lead responsible were switched round at the coil. (just doable without taking off the manifold but a b1tch, causing bruised knuckles).

The way the coils work, if you don't already know, is on what is called the wasted spark principle. In this system all the plugs are paired with another one
as follows; 1-6. 8-5, 7-4, 3-2 and the 2 coils power 4 each, left does 1, 6, 7 and 4 and right does the remaining 4.

The firing order is 1-8-4-3-6-5-7-2, so in order of firing when the left coil sends a current to plug 1 on its firing stroke, it also send a current to plug 6 on its exhaust stroke and so on and so forth, 8 and 5, 4 and 7, 3 and 2 through the fire order. If you have mixed the leads for 1 and 7 you can see that neither of these will be getting its current on is firing stroke. So just because there is a spark at 1 or 7 means nothing as they might be out of sequence.

 

Oh, 1 and 6 are companions! He had said that 1 and 7 were the misfiring cylinders and also companions on the same coil.
Not a big deal to me, but your firing order is missing a #2. He might need it, if he doesn't have that info. already.

 

Hi thanks the miss fire started after many months of trouble free driving after replacing the coils and leads

 

Well, that's certainly not going to be mixed up leads then. If the two cylinders with the misfires are companion cylinders, it could be just that one coil in the pack. Of course it could also be a control or wiring issue. Have you determined whether or not you've got spark at either, or both cylinders?

Another quick and easy way to determine what type of misfire it is, is to check your scan data and see what your O2 sensors are reporting. If it's cylinders 1 and 7, it should show a rich condition on bank one only if there is no spark in one or both those two cylinders.

I usually check everything out really well. While misfire monitors are usually pretty accurate, they can be wrong sometimes. I had a Toyota come in one time that had a code for a #1 misfire, but it was actually #3 that had the misfire. It was a coil over plug system too, which if you think about it should be more accurate.

 

Yes I did 'miss' on No.2, sorted now.

The point about miss connecting these 2 plugs is that by doing so the spark that should go to 7 on its firing stroke would go to 6 which is somewhere in the middle of its cycle between firing and exhausting and visa versa so both would misfire. An easy fix would have been to just swap the leads between plugs 7 and 6 but they may not stretch.

However, Celto 4's saying the problem is not due to mixed leads as it has been running OK for some time after changing, coils and leads. So back to checking for spark at the plugs.

Remove the plugs to 6 and 7 one at a time and with the lead attached hold (with insulted pliers) to a good earth. Have someone switch on the ignition and see if you get a good spark. If you get a good spark I'd start to suspect maybe a fuelling problem, maybe injectors.

TOO SLOW must type faster

 

No big deal man, I wasn't trying to be a jerk. It's a simple mistake

 

hi all just started the Landy!!!!!!!running smooth and no codes lifters clattered a bit but its been sitting and they calmed right down put sea foam in the tank aan will do will do top end Thanks to everyone happy Memorial Day!!!!!!!!