no spark

[avengnce]

Well here is a brain teaser of sorts . My problem is : I have a 68 Coronet with a 440 / holley 750 . It runs fine when it runs . All of sudden , hot or cold , it will just die and lose all power the engine . The lights stay on and everything else. The motor will crank and crank but no starting like there is no spark . I have replaced the ballast resistor and VR . I put a fuel gauge on the fuel line thinking it might have vapor locked . It has steady fuel pressure still but no starting . I pulled the dist cap and the rotor is spinning  ( mallory unilite dist ) . I got power to the + side of the coil but no power coming out of the coil . Should I be able to see power coming from the coil with a test light? Also I have power on both side of the coil terminals? I am thinking that maybe I have a bad ground and it is screwing with the coil? After a while the car will start and run like normal. It will start sometimes 5 min or a few hours . no rhyme nor reason . It doesnt seem to be engine heat related to me, but maybe? any ideas or directions I should go from here? I am going to rewire the ground for the coil in the am . but I am not sure this is the problem . Any help here would be GREATLY appreciated . I have been beating my head on this for years!!!





Ron

[rt green]

put on a new coil. it could be getting hot and causing  an open circut.  one way to test, is to catch it in the act and put an ohm meter across the coil terminals and see if you have continuity.

[Heck2G14]

yep,yep, Im thinking coil first then all engine grounds.

[avengnce]

I put on a stock coil and it started but died after 1 min - then same thing  . Cranking and no spark - Might it be the ignition module in my dist going bad? It is a mallory unilite .

[Heck2G14]

really check all your grounds throughly and clean them ( battery to Engine, ballast to firewall, ecu to firewall, volt.reg. to firewall.) Dodges really seem picky on a good ground. If that doesnt do it I'd take a close look at both your coil and distributor.

[rt green]

one area you could check would be the  junction block on your firewall. they are known for bad, burnt connections.