XJR Misfire

[Jnr]

Hello chaps,

Was just wondering if any of you had a bit of advice on a random misfire I'm having with my 96 XJR.....

Engine has had new plugs and number 5 cylinder's plug was pretty much black so changed the coilpack for that plug.

Car is still having a misfire intermittently which is rather annoying as the straight six should be nice and smooth.

Any ideas on what else to look for before going to a dealer??


Thanks in advance for any replies.
John

[ringram]

Plug leads..
Especially on number 5

Edited by ringram on Friday 9th November 17:11

[Trooper2]

Wouldn't a 1996 XJR be coil-on-plug? No leads.

[Jnr]

Indeed, no plug leads.

Have already changed the coil pack for number 5.....

[Trooper2]

Dirty injectors or MAF sensor?

Try some injector cleaner in the next few tankfuls and see if it helps.

I seem to recall reading that the MAF can get dirty enough to cause problems but not set a code. You could try unplugging the MAF and see if the misfire clears but that will definetly set a code.

[Jnr]

Trooper2 said:

Dirty injectors or MAF sensor?

Try some injector cleaner in the next few tankfuls and see if it helps.

I seem to recall reading that the MAF can get dirty enough to cause problems but not set a code. You could try unplugging the MAF and see if the misfire clears but that will definetly set a code.

Cheers,

Will give this a go over the weekend....

J

[ringram]

Now educated

How about a compression and leak down check on #5 has it done loads of miles?

Edited by ringram on Friday 9th November 22:52

[gary11]

may have burnt valve
gary

[Jnr]

Well chaps,

After filling up with a tank of V-Power and a can of injector cleaner, the random misfire has totally disappeared!

Such a simple solution!

Thanks for all your help,
Cheers
John

[melhook]

These were known to have sticky valves, your injector cleaner and good quality fuel has probably helped free them off. Also a good old fashioned blast helps.