Engine misfiring /Fault codes , 1996 XJ6 odb2

X300
1

I scanned for fault codes on my 96 XJ6 that has a bad misfire. this has been discussed some under the topic new owner questions. here are the codes:
P0300
P0303
P1314
P1313
P0430
The book that came with scanner does not have the last 3 code descriptios, the first 2 are random misfire and misfire on # 3

2

Random misfires at this stage…change the plugs with gaskets and put all new coil packs.
The wires get very frey under the cover make sure none are cracked or broken.
Change those coil packs your running 4 out of 6 cylinders from your above numbers.
after 300 303 the rest is due to misfire or no spark, don’t keep running the car our your cats will load u, then your in for ALOT OF CASH!
Plugs/gaskets and coil packs a couple hundred bucks…
GOOD LUCK.
GTJOEY1314

3

just a suggestion, but if it misfires consistently at idle try the following:
1 remove the valve cover top to gain access to plugs and coils.
2. run engine at idle
3. remove and replace coil connectors one at a time to try to isolate misfiring cylinder

if you can detect a cylinder misfiring then try one or all of the following:

  1. replace plug coil and coil gasket for that cylinder.
    2…swap coil to another cylinder to see if problem follows marginal coil.
  2. swap plug to another cylinder to see if problem follows marginal plug.
  3. check plug gaps if you take the plug out.
  4. check plug “wells” for oil buildup from leaking head gasket (wick up with paper towel when cool)

Thanks to another member I found out that a bad coil can feed back into the computer and cause very rough running.
3.

4

I seem to recall from way back that it possible to CROSS the connectors on either 5 & 4 cylinders or 5 & 6 this causes bad idling and misfiring.
Perhaps someone else will remember which it is.

5

just wanted to clear things up. my engine now fires on all 6 cylinders. I removed all the injector connections to test resistance. all tested equal when i reconnected and started the engine all cylinders were firing! I can only assume the problem was bad connections as i replaced nothing. The car now has a high idle which i was trying to sort out without success. As I am now located 1400 miles from the car for summer farm work and relaxation I wont be able to try anything new till next fall. I thank all for suggestions . I had great difficulty logging on just now, had to change my password. not sure whats going on there…Should i need a name change too i will advise.The last thing done this spring was connecting a sophisticated analyzer to the engine, for some reason the cars module will not communicate. Perhaps the ECM is faulty but it is now beyond my ability and i will be getting professional assistance. Glad to be away from it, planting sweetcorn tomorrow :slight_smile: