XJ6 SII 1975 with Crane Ignition dies when warm

[bmurphy7369]

Here I go again, another question about the XJ6C. I know that the ZS (water chokes) carbs not leaning the mixture enough while engine is at warmest idling could be one issue. The thing that makes me wonder about ignition is that I get absolutely no firing sound until the car almost is completely cooled, then it seems to run fine until the temp guage goes slightly above center. Could there be a coil issue, seems like I have heard of this years ago, or something such as the gap on the points in the distributor needing to be set differently.

This car has a crane ignition module, the vacuum advance port on the distributor is blocked of, and what I think is the other port for the advance hose (behind carbs on an air rail, pointing downward) is not plugged. There is no vac. advance hose at all on the car.

I had a friend spray starting fluid as I cranked the engine and I would have thought that at least I may get a momentary fire up, but nothing. There is no heavy smell of fuel near the carbs, checked the fuel pump, working fine and keeping constant pressure to to carbs. Any ideas, I am sure this is something simple that I am missing but could also be a combination of emmisions parts missing, carb sync and timing issues as well I suppose. If anyone has any thoughts on this, please reply. Thanks in advance.

Brian

 

[maynard]

The Crane ignition system has a history of failing when hot. This is a symptom that the amplifier is going to die permanently. Replace it.

 

[bmurphy7369]

Maynard,

So they can fail when hot, then work when cooled off? I would be tempted just to do away with it altogether, but if it is helpful when working properly I'll replace it.

Thank you,
Brian

 

[jessebogan]

The easiest way to cure the carb problems forever is to find a set of series 1 carbs, and the manual choke set up. You cant just switch the chokes as there is some linkage involved, and the throttle shafts are different sizes.The holes are there under the edge of the dash to mount the manual choke lever. It is an easy conversion, and well worth the effort.

I have converted some series 1 and 2s to the ignition system out of a series 3. I realize that you had some trouble with that before, but the reality is they are pretty reliable. A lot of "solid state" units fail that way Many a time I have limped home a few miles at a time.....

 

[DrEntropy]

Manual chokes on the older units is a bit of cash in the beginning, but WELL worth doing if you intend to keep the thing.

"Surrender, Dorothy!" Start hunting a set and fix the prob.

A lot of "solid state" units fail that way

Dead giveaway as to the problem. I'd guess between you and me, Jesse, we could fill multiple 55-gallon drums with the defective ones we've replaced! /bcforum/images/%%GRAEMLIN_URL%%/jester.gif

 

[RonMacPherson]

Did you pull a plug wire and check for spark?

Need to isolate a failure to one system, fuel, ignition or timing. I would think that one of the plug wires would be accessible so that you can pull a wire, place a plug(spare one would work) in the wire, holding it to ground(valve cover) and see if you get a bright blue spark. If not the Crane is warrantied for Life, so contact them and get a new amplifier. I have not heard of ANY failures of the amplifiers, but it is electronic, it can happen(I've have my Crane from when they were Allison and it's been transferred to its third car.

Coil? could be.. Just find out if spark or not.

 

[bmurphy7369]

Hello guys, and yes, I belive you are correct. Unfortunately I started this project for total originality in the end, so the water-chokes are a new investment and I want to give them a try for a while. I think that once everything else, timing again, valves, new coil, maybe a new Crane module is completed, I won't be as dissapointed in myself. For the future, where can I get a new choke cable (dual)? I still have several sets with manual chokes here, including the ones that were on the car when I bought it, burned the cables in an air cleaner fire before I took possession. I am considering Webers as well, but for now I have to get all the bugs worked out as I have put too much effort into the fuel system repairs from the fire damage. Luckily it was a carb issue, I had feared it was an engine issue that caused this initially, but haven't had even a terrifying backfire since the rebuilt ZS autochokes were installed. Thanks for the nudge, I am leaning that way heavily...

Brian

 

[DrEntropy]

For the future, where can I get a new choke cable (dual)?

These guys were a good parts source for us when we were a restoration shop: Engle Imports, 800-253-4080

No affiliation, just another parts house.

 

[jessebogan]

Try Jack White. Great used parts, and a lot of really good part interchange knowlege. 1 540 743 4037

 

[bmurphy7369]

Thank you all for the leads on the cables and the info on the Crane.
I am trying to completely renew all the wires to the ballast resistor/coil that complete the ignition circuit. The wiring has apparently been redone/scorched and I can't make sense out of the Haynes diagram to locate the colors, even if they were correct and identifiable.......

I have the three prong setup from the Crane to the ignition coil sensor. This is correct and unharmed...

The Crane's manual shows a typical OPUS setup, as on the MG/Triumph with the OPUS. Since I don't have the original Lucas Ign. Amp. in the car, what goes to POS on the coil, Neg on the coil and then what kind of jumper setup for the ballast resistor (also to coil, NEG and POS I believe) is recommended... the instructions for "All Jaguar with OPUS" don't match my car at all, I guess since the Lucas Amp is gone. If you know the wire colors or what should be hot when key is switched and where it goes, and what should be to the negative, the best way to join these all together, etc. I think I would have the problem solved. I usually don't have much trouble with a wiring diagram but the Haynes is mind-boggling to me at the present.

Thanks again, any tips, I would be greatful..........

Brian

 

[bmurphy7369]

Clarification:

I think that a jumper from the ballast resistor to the coil has to be used/made to give the system around 3 ohms of resistance... half or so from the coil and the other from the resistor. Is this jumper wire setup created by bridging the two terminals on the ballast with one wire between both spade termials, and then one wire each back to the coil Pos. and the coil Neg. Essentially, the crane has neg and pos to the coil, join them with the out on the respective coil terminal sending a wire to each terminal on the ballast, and also a bridge one-wire between each of the ballast termials?
That seems to be the diagram for the OPUS ignition without the Lucas original ingnition amp, but my wiring diagram skills are rusty...
Thanks again to all......
Brian