1. Home
  2. Jaguar Autos
  3. Mk2 won't go

Mk2 won't go

Got a little problem with my 3.4L Mk2. It has been running superbly until last Friday when all of a sudden it started misfiring and losing power almost completely. Managed to limp home and when I pulled the plugs out they all had beards of soot. Now, compression is good on all cylinders, spark (on clean plugs) is good on all plugs, have pulled the carbs apart and reset them no problems so it idles nicely, revs nicely. Get the car on the road and it runs well with the gentlest throttle pressures but a little more throttle and no power and in minutes the plugs are fouled again and it starts missing again. Starting carburettor is a suspect, I guess, but I have long since disconnected the thermal switch and replaced it with a switch in the cabin, and it is definitely not open by the solenoid anyway. It has three mechanics at my local garage baffled (not Jag specialists but the local centre for vintage car repairs). Any suggestions?

GrahamL

Reply to
Graham L
Loading thread data ...

"Graham L" wrote in news:i_ZKc.8231$ snipped-for-privacy@news-server.bigpond.net.au:

Sounds like the coil, whack another in and see what happens.

My XJ6 usually starts missing under power when the plugs are weak. The 420G started doing the same thing, so I replaced the coil, as the plugs were new, it fixed the problem.

Ron

Reply to
Ron the Barbarian

Thanks, Ron. It had crossed my mind but the mechanic talked me out of it. I'll try it today.

GrahamL

Reply to
Graham L

Besides the coil the "Barbarian" mentioned ->What brand of plugs are you running? What is the heat range ?

Carbon fouling is typically caused by the folowing-

1.) Plug heat range too cold.
Reply to
Blake Dodson

snipped-for-privacy@comcast.net (Blake Dodson) wrote in news: snipped-for-privacy@posting.google.com:

Reply to
Ron the Barbarian

Do not want to alarm you too much but I had the same problem on a Jeep CJ7 straight six, turned out to have a crack in the block

Nick

Reply to
Nick Bennett

Cmon Ron, I knew it was you...but if you are projecting that to me you are simply wrong! Hell, I am a savage. ;-)

Blake (Nice website)

Reply to
Blake Dodson

And a cracked block caused dry fouling?

Reply to
Blake Dodson

Reply to
Graham L

Sadly, Mike, Bodecia, warrior queen is still in the garage with bits of her carburettors spread out on the bench. I can't find any problem with the diaphragms but I'm replacing them anyway as soon as they arrive in the post. Still open to suggestions.

Graham

Reply to
Graham L

Did it ever go???

Can we please have the outcome.

Ta.

Reply to
The Three Kings

This somehow reminds me of the time my cafe racer exhaust pipe clogged....

Good Luck.

Blake

Reply to
Blake Dodson

Yes, Blake. That occurred to me, too. Plates can dislodge in mufflerr, for example. However, the Mk 2 has two separate exhaust systems, 3 cylinders each. All the plugs are fouling up at the same rate. With several other disasters to deal with over the last week, I haven't had time to look at it. I am going to replace the coil, condenser and spark plug leads. If that doesn't work, at least I'll have some spares. Graham

Reply to
Graham L

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.