I changed my coil packs, plugs and wires about 3 months ago no issues until about a month ago I noticed a slight miss while at idle.. Then about a week ago the SEL came on and gave me the 4 even # cylinders and a 1300 code and the multiple misfire code. I bought new plugs again but this time time I used a double platinum autolite and I also purchased STI wires..I noticed a big difference in performance but the missing is still there and not all the time just during low speed or idle.. at least that is when I can tell its missing..although the SEL has not illuminated as of yet.. I have been reading other post with similar problems some point me in the direction of VSS ... I have a 2002 DiscoveryII ..Does this vehicle have a VSS ? I could not find it in RAVE but I found the speed signal sensor is located on the tranny..does this provide the same input for the speedometer in the dash? Any suggestions?

 

you should check the RAVE but I do not believe there is an odd coil and an even coil.
I believe each coil fires odd and even numbers, if so probably a gasket problem.

 

It's not a coil problem cause those misfires are on both coils.
Do you have anything else other then the 1300 codes.
I have seen this before, usually on the other bank and am not sure if it is vacuum or electrical.
If you have a good Rover mechanic, check with him and let us know what you find.

 

Thank you both for replying. I thought that I should clean my throttle body really well first. I have been wanting to do this anyway since someone posted the "how to" on it. When I looked at it while changing the MAF it was kind of fouled up looking around the bottom half of the butterfly valve. Again since I have changed plugs and wires no SEL has come on. I have had tranny issues with this truck ,changed the TCU recently; which point to electrical problems. I have read up on the GEMS OBDII system and it seems that my engine timing (ignition advance) could be affecting the shifting of my tranny as well. Can a rover mechanic pull up data that I have cleared already?

 

The T/B being dirty won't cause this but should be cleaned.
What is going on with your tranny and what fault codes do you have?

 

No fault codes just tranny dropping offline and only getting 3rd and 4th gear no reverse, park or 1st and 2nd...No readout on dash LCD or illumination of red lights along the gear selector..This has happened twice but is not occuring right now ...The tranny seems to lag sometimes when I really gun the accelerator..and I sometimes get a slight slip when I put the truck in reverse and drive then press the accelerator quickly...being in a hurry to get somewhere.. The first time it did it was before I changed the plugs wires and coils.. It did it again about 4 weeks ago so unplugging the TCU is what I did before to fix it or more accurately "trick it" to operate.. This last time unplugging the TCU did not work right away...It took about three days of unplugging it and the battery over night before the tranny would go into all gears and shift decent..so I bought a used TCU and put it in..no issues accept the slip when I get in a rush.. see our conversation
https://landroverforums.com/forum/di...roblems-51868/

 

Look at this conversation as well

https://landroverforums.com/forum/di...e-issue-55555/

 

Wanted to try and finish this conversation..OK I changed my crankshaft position sensor..still had misfires..disconnected exhaust on both manifolds thinking my cats my have been clogged..still misfiring...Thought for a minute and decided to get some oil additive...added 2 bottles to oil...at first misfire was still present..then gradually the engine has stopped altogether..this is the third day and engine is running a lot better..Any thoughts on what could have been sticking... valves maybe? Should I do an engine flush with my next oil change?
Thanks in advance

 

any signs of what going on with the plugs? have you checked them?

 

I did pull the plugs on the passenger side ...they had some carbon build up but they did not look bad...I wire brushed them and stuck em back in.