Crane XR700 help needed, car won't run

[Brosky]

I replaced my PT distributor with another recurved unit with the original points setup. One of these days I'll throw the Pertronix dizzy back in when I have nothing better to do that day.

 

[TR3driver]

You cant leave the switch on the xr700 either because it will overheat the coil.

Not true of current manufacture XR700s (the ones with the LED on the brain box). They sense when the engine is not turning, and shut down the current through the coil & power transistor.

But even the old ones wouldn't overheat the coil any worse than with points ...

 

[RonMacPherson]

Paul,

I had NO problem installing in my TR. And that was back in the 87. Course the insructions came from Allison, as that was before Crane bought it. Maybe the instructions changed.

Perhaps it's just a conceptional problem, or improper installation instructions. A lot easier, in my estimation, than altering a thee carb linkage hookup.

Perhaps a visit to Crane's website might be informative.

I still consider them the best buy for the buck.

 

[zmayne]

Thanks Allan and everone!
Allan, your suggestion to position the shutter 1/3 from the bottom may have been the cure. Car started right up and ran like a champ. Seems to pull better, esp. at high rpms, the way it should what with triple carbs, cam, etc.
About the ballast resistor. Car is running fine. I drove it for about 15 minutes and the coil was hot to the touch, but not enough to burn me. Could be from the engine heat as well. Does that mean I'm good with the sport coil, or do I still need a normal coil? Also, could I have a ballast resistor and not know it? And, the really dumb question, where do I get one? NAPA, etc?
Thanks again!
Zach

 

[ALLAN]

Zach, I had to go back and read my Crane instruction, they say no ballast resistor with the xr700, in fact they said if you have a stock coil with an internal resistor-that you must change the coil. Stay with your sport coil as long as there is no internal or external resistance, I was running a 50,000 volt coil with my xr700 it ran great.----It was good to see what TR3driver said about the new units not burning the coils up, so Zach you should be good to go.



I went back and read the instruction again, there seems to be some conflicting info, in one sentence they say if original equipment had a internal or external resistor than you need to use one (only one),but in the very next sentence they say for maximum performance any ballast resistance must be bypassed ????---You better contact Crane on this one

 

[RonMacPherson]

Way to tell if you've got a resistor(ballast resistor) or wire, etc. Is to measure voltage supplied to the coil.

With a voltmeter(cheap ones work well) measure the voltage to the coil when the engine is running. Should be greater than 11 volts. If not then you've got a resistor in circuit.

 

[TR3driver]

Yah, seriously confusing. Problem is, the instructions cover both XR700 and XR3000; which have different requirements. The XR700 must have resistance in the circuit (inside or outside the coil); while the XR3000 should NOT have resistance in the circuit.

So, for the XR700, you should either use a "12v" coil (which has the resistance inside it), like the original coil or most (not all) Lucas 'Sports' coils (they come both ways). Or, you can use a more modern coil and add a ballast resistor. Should be able to find one at NAPA, etc. If they claim they can't figure out what you want unless you supply make, model and year; try a 1967 Dodge Dart with a 225 ci slant 6. Or a 71 Triumph Stag with a 3.0 V8 ... it's so much fun when they ask "Triumph ? Who makes that ?" /bcforum/images/%%GRAEMLIN_URL%%/smile.gif

 

[ALLAN]

TR3 driver is right, the instructions are really confusing, I read them again for about the sixth time and they still are. Like TR3 driver said you need a Resistor for xr700, so Zach you do need a resistor and like you mentioned Napa should be a good source for it.