Hi
well you cant have a spark or it would at least cough
Do you have a cheap blue distributer cap? If so pull it. There is ONE reason you could seemingly have spark to the cap, AND injection, but no start. The center carbon in the cap has fallen out. It did on my cheap blue cap (Until I went with an OE cap).
Just basics:
The ignition is upstream of the EFI Fueling and cars only need fuel, fire, air, and compression to run. Given you’ve tried ez start and verified coil operation, yet no coughs, it’s either the spark not being distributed, OR a mechanical failure/compression. Unless the jackshaft is stripped (which has happened on two very rare occasions that I know of) I say check that cap…
The EFI functions ONLY if it gets the RPM signal (as you’ve correctly noted) to the ECU… which is why you have injection (or seemingly do). The CTS , were wiring bad or it bad, would usually cause massive over fueling to the point of no start. So generally pulling the Fuel Pump Relay or the Inertia switch up will disable injection to the point where cranking blows out flooding, and you get a few coughs before it dies. So although the CTS can be a big problem I’m not so sure that’s the issue here. Worth checking though.
~Paul K.
FYI, the current OEM cap is a cheap aftermarket too. It is black with LUCAS on it. The aftermarket is identical to the OEM, but 1/3 the price. I’ve bought both and it’s true.
BUT it is superior to the aftermarket blue cap, that’s for sure.
My black Lucas cap developed hairline cracks after just 2 years. Still worked, but it needed to be replaced. Bought another Black Lucas cap. I may stockpile a few for the next 20 years 
Original 80s OEM is superior, if you can find one!
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Hi Greg,
That check list is not really for this situation, although it might help.
It is for somebody who has just bought an old V12 car that probably never ran for the last few years.
Paul’s car ran until recently, so probably just one item has failed.
Keep in mind that a V12 at 12:1 is capable of firing ether based starter fluids without spark. Failure of the CTS will usually let the vehicle start but not run for long. This rich running albeit short will only add to the carbon shorting the plugs.
I know it can be be a group of things but I would be diving into exclude the plugs being gummed up with carbon.
There is a lot to be said for the Italian tune up once she is up and running.
Hi Henry, yes, i agree. I seem to have a spark, I seem to have fuel so i should get a bang, bloody old cars, but i had very few issues with my 62 Morris Minor that i got at 16.
Italian tune-up? Go on then…
Yes, i think I’ll check the CTS but i hve my doubts and then its on to removing the ancillaries and looking at the plugs.
It’ll be a good opportunity to clean the valley.
Hi Richard, agreed but I’ll go through it. My car seemed to run a bit rough, like on 11 cylinders, then it sort of spluttered and stopped, got it started again briefly and then she was gone. I’m still thinking fuel starvation, but puzzled by the ‘no bang’ with starter fluid.
P.
Once you have the sparks out you will be able to see if you have good spark in all of them when you crank the engine.
The fact that nothing happens with starter fluid indicates ingnition problems.
OK I’m going to ask the dumb question, did you change the fuel filter in front of the spare wheel. Also did you yard out the sump fuel tank clean, and change that stupid filter on the pipe into the tank. You wouldn’t believe the crud that came out of mine. I’m amazed the car even started or ran.
Hi, I did make sure it was all clean, but that’s not to say there isn’t still crud in the system, but i do have fuel at the injectors. Im going to remove them again and do a more through test on them
And a more through check of the spark plugs.
Cheers,
P.
Lots of good advice here.
I would suggest pulling one plug from each bank after cranking. Should be wet with fuel, right? This will also give you a good look at the plugs.
I can tell you from experience, too, that if you foul those plugs too badly, you will not get them to fire. In my case, I had a severe vacuum leak in the line running from the manifold crossover to the ECU. I put several sets of plugs through this car until I found what the issue was.
-M
Forgot to add, have you messed with the timing at all? If the dizzy has been moved, your timing can be so badly off that this can contribute to the symptoms.
Also, some have experienced stripping of the drive gear on the end of the dizzy, and that will also give a bag of cats for response. You can check that by pulling the dizzy, but be careful to mark precisely its location, and to re-time your distributor (e.g., timing light).
-M
Thanks Mike, my job tomorrow is to get at the plugs n see whats happening there, also going to properly see whats happening with the injectors.
I should have bought a Toyota… nah!
The Italian tune-up by Ferrari - Sgcarmart
Italian Tune Up is a method to burn off the carbon deposits in the combustion chambers by running the engine at its maximum load, forcing the injectors to flow
Look up “Italian Tune Up”, it is called Italian because it is.credited to Enzo Ferrari
Hi Paul, im stripping off the ancillaries tomorrow so I’ll get a look at the distributor, yes, it’s a nice blue one. I’ll get to check the spark at the plugs too.
Cheers,
P.
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Ah!, got it… oooh, a bit scary, i might try it on a hire car first…
I must admit, I’ve never performed an Italian Tuneup on my V-12. I chickened out every time I had full intentions of doing one.
And I’ll tell you why , first reason is this engine is over 30+ years old. I’m trying to show the old girl some respect.
Second reason is if I overheat or see a piston come through the bonnet , I’m an idiot at the side of the road, with not enough deep pockets for a V-12 engine rebuild.
Reason number three would be , what is the red line on your V-12 tachometer vs real redline on a 5.3 litre V-12 (some say around 8000 RPM) so who is going to test those waters.
The few times I tried I was in second gear at over 5000 RPM at over 100MPH and still climbing.
I chickened out .
The defining reason is still go back to reason one and two. I’ve put way too much time money and effort into this car to risk that sort of catastrophic event.
Others may chime in.
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Hi Gary, that’s brilliant. Me too on all counts. Ive no idea how fast my car goes, but it’s a LOT faster than I’ll ever take her.
Gary . . .
Showing the old girl some respect is what gets the cylinders all carboned up in the first place.
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