v12 firing on one bank only

pull all the plugs out and see if they are all firing.......the injectors are all clicking so they should be getting fuel, while you do that check all the COMPRESSION FIGURES, no compression = no firing...........

Rodd there is one other answer---does your car still have all of its cats. That car has 2 pre cats and 2 cats in the down pipes--I guess you could have had a sudden stoppage in your cats that would not let the engine breathe--if all else fails remove the down pipe to that bank and test it--

yes but timing out on that car is timing out--You can not affect 6--timing affects all 12. Rod I am sort of out of ideas--you did not say if you checked the air filter on the bad bank--BTW which bank is it A or B? Or looking from the drivers seat right or left? You said the linkage and arms are working --please go and check the throttle itself is opening--also make sure that there is not some rag or something in there--this is a real puzzle.

Nope, the changing the ignition wouldn't cause just one bank to give problems.

Refresh my memory. How did you determine one entire bank was dead? What are the symptoms?

Cheers
DD

Thanks George, yes the throttle linkage and arms to the TB are working fine.

A new idea-- can the timing have anything to do with one bank not firing? I had a mechanic unfamiliar with the car mess with the timing just before my problems began. Could this be a problem?

Rod

When you turn the turn table that operates the rods to the T bodies --make sure all linkages open that all linkages work in opening the T-bodies--have you removed the air filter on the offending side? I think you said you changed them--make sure the filter you replaced is not in backward.

Checked the car today. Listened to the injectors and all had a loud clicking noise.
What's my next move???

I did not check the throttle body. What should I be checking for ??

Thanks!

Rod

Rodd did you check the throttle body on the offending side--is it working?

hi guys-

sorry for the delay in my follow up posting here! had a medical emergency with my mother in law, and had to spend the weekend at the hospital!

Anyway, I have a 1988 Cabriolet, Lucas distrub., and one small square coil that is mounted on the forward end on the linkage post. I do see a second coil that is mounted up in front of the radiator, but its wires are cut. The car ran fine for years with this configuartion. Now I still need to get to listen to see if the injectors are clicking as was asked last week. I hope to do this tonight and I will post to the group.

Again, sorry for the dealy-- I am very interested in getting this problem solved and apprciate the groups time and expert advice!

Rod

Art you could be right but with the information he has provided I think we need to look at situations that limit a 12 to one bank---but it seems we are more interested than he is.

injectors can be a problem , I just changed 2 on a 6.0 that had been sitting around for a couple of years........ if the engine can be kept running get a stethescope , or a long skinny screwdriver and place the end against the plastic part of the injectors. they should all have quite a loud tapping.they should all be of a similar volume. if tapping is absent from any they need cleaning or renewing. this has been my experience. the small squarish coil from Jag works instead of the two round ones....I put one on my 5.3 almost twenty years ago and I think it is still good......now it is on the 6.0....
I would also disconnect the fuel rail and see visually how much fuel is being pumped, should be pretty good amount.. note the fuel comes in from the passenger side line.and is returned to the tank on the driver side and thru the fuel cooler......
you could also remove non compliant cylinder plug wires and attach plugs and check for spark

I seem to recall something about Lucas V12s eventually being built with the single square coil (DAC6093) but it was only on the Series III saloons....not the XJS.
Don't take mine as the final word by any means but, to verify that it ever happened, I'd look n the Ser III parts catalogs that cover the last couple years of production.

It isn't too uncommon to see an XJS retrofitted with a single DAC6093 square coil or even a single aftermarket round coil.

For the purposes of this thread the important thing is that we know that Rod doesn't have a Marelli car.... which has been established.

Cheers
DD

Art he said he had one small round one and it is an 1987--right? As far as the square coil I am loking in RTC9888CE and do not see it--where do you find that?

George, some later Lucas ignitions only had one square coil instead of the two normal round ones..........

Rodd you actually have a second coil for heavy use (look in front of your radiator and condenser and you will see it--but in any case it is not in play here. I think that the injectors are not firing also but the only other time I have seen this is when the linkage fails to the throttle body and insufficient air is in the chambers-the engine is in fact injection and the plugs are firing but the mixture is too rich to fire--if so see Williams comments and fix the linkage--change the oil---remove the plugs and air out the chambers--then put some light oil down the bores and let it set a day or two (not too much oil just a couple pumps from an oil can---and lastly cross your fingers and pray--if this condition has been this way and a bunch of miles have been put on it the cylinders are most likely washed down and damages--I am hoping for a bad electrical connection on the injector rail!!!!!!!!

William-

Yes I have the Lucas system with the one small coil behind the distr cap. I recently replaced my cap and rotor, so I know they are good. Oil level is lower end of ok and no smell of fuel. i do carry a fire exting just in case!!

Thanks.

Rod

Rodd, you say 1 coil so i'm assuming you have the lucas system. Before doing anything else remove the dipstick and smell the oil, if the level is overfull or you smell petrol fumes. "DO NOT TURN ON THE IGNITION". if no smell then it is OK. A common problem is that one bank can flood with fuel creating a very dangerous situation.

i will ck for injectors clicking this eve. Thanks guys!

Rod

Are the injectors on the dead bank clicking?

Cheers
DD

Hi Rod,

Pull the distributor cap and look at the rotor. I suspect the rotor has failed for A or B bank. If so replace with a Jaguar rotor and maybe a new distributor cap. I usually look for the simple things first!

Good Luck,
Dwight

Are the injectors on the dead bank clicking?

Cheers
DD