1994 V12 convertible. Big loss of power three months ago had it towed home and put repair on back burner.
Looked at it today and noted smoked driver side ignition amp and wiring. Was thinking the rotor and cap might be bad but have not looked at those.
Would it be okay to repair wiring and replace module then hook up an oscilloscope to test further, or should I visually inspect cap and rotor first?
I generally like to test one thing at a time to rule out possibly disturbing something else and possibly causing an additional problem. However if a defective part is causing the amp to burn out would like to rule that out beforehand.
Inspect the cap and rotor first! Make sure that it has not had to classic Marelli failure in the cap or rotor. If you are not aware of it take a look at Kibert section on it in his book for this car. (http://www.jag-lovers.org/xj-s/book/XJS_help.pdf). Sounds like it may have had this failure, It could also just be that wiring to that cylinder banks amp.
I don’t know anything about the 6.0 V12 cars, but if this happened to a 1990 5.3L V12 like ours I would remove the spark plug leads to inspect their condition, the spark plugs to inspect their condition and gap, the distributor cap and rotor for condition, and the exhaust system to inspect the catalytic converters.
Thanks Paul. I just bought the car with several known mechanical problems that are within my abilities to repair. That car cruised 80 mph on the interstate for an hour like nothing. Pulled into get gas and before I could get to the pump it just fell on its face.
Pulled B lead from coil to distributor and it still ran bad. Plugged it back in, pulled A lead and it would not even start. So I knew there was a bank out.
Glad I did a lot of reading up on this and it happened while idling.
Thanks for taking a look. On to the other suspects; wiring, coil. ignition module, trigger wire from ECM. Hope I find something before that bit of expensive equipment.
Nevermind It looks like your model is different than the 1990-1991 Marelli systems. one coil does in fact get two wires and the other gets three. the wires are shot though so that might be your cause.
Saw one spot where the insulation was gone. Noticed a few more. Wire is shiny so may be recent. Plug wires seem very pliable and hand numbered. May be recent replacements and brittle insulation may have cracked in other places, wire break or coil wires shorted.
