Stovebolt.com Forums The Shop Area The Engine Shop loss of spark after about 15 miles of driving

I have been trying to solve this on my own for a while with no luck so I'm coming to the experts. My 1949 truck has a 1953 engine that I converted to Protronic's electronic points. Everything else is pretty much stock except I believe the distributor cap and rotor are for a 216 engine not the 235 that is in it. The problem occurs after driving about 15 miles on the expressway. I suddenly lose spark and the engine backfires and dies. After letting the truck sit for 5 or 10 minutes it starts up and goes and will fail again after 10 miles or so. I replaced the coil with a new Protonic coil, the spark plug wires with Protronic wires, and put a new Ignitor II (Mfr. #: 91168LS) in. Did not fix the problem. I have the ballast resistor bypassed. One of the first times it happened I coasted into a gas station and we tried using Ether to get it started and it did not work that is why I believe is spark, not fuel. Any ideas?

Thanks,
Terence

What kind of condenser are you running? Take a look at the stickys about upgraded condensors, that sounds like a classic case of heat soak.

Edit: https://www.stovebolt.com/ubbthread...native-condenser-update.html#Post1388813

"Protronic's"? If that's anything like "Pertronix" you just answered your own question. "A spare point type distributor - - - - -don't leave home without it!"
Jerry

Dang spell check PerTronix 91181LS - PerTronix Ignitor II

Terence

http://www.langdonsstovebolt.com/store/#!/Stovebolt-Mini-HEI-for-GM-216-235-261-&-GMC/p/1222040/category=18665949

Get this. I have one on my ‘62 261 in my 51 GMC one ton. Runs great. You won’t regret it.

PERTRONIX 91181LS IGNITOR II DELCO 8 CYL LOBE SENSOR????

A quick check for Chevy 6 cylinder (please verify yourself):

PerTronix 1168LS 12 volts
PerTronix 1168LSP6 6 volts

You don't need to use a Pertronix coil. Original is more than adequate.

Ditto on langdonsstovebolt Mini-HEI-for-GM-216-235-261
BUT.....Heaven forbid anyone finds out or notices.....FORD parts.

This could be as simple as gas cap not venting.

My opinion of Pertronix ignition systems is well noted on the site so I won’t go into that. As Bartamos mentioned in his last sentence, loosen the gas cap and go for a drive. If it doesn’t die you found your problem. If I’d does croak, pull off all the Engine items with the word Pertronix on it and put the stock stuff back in. If it dies after this come back for specific tests to get you going. Good luck.

Lets deal with a little low hanging fruit, the distributor. Take the cap off and get the delco number from the breaker plate. Lets see what you have there to begin with. The Delco number will dictate which style cap and rotor you should be using.

NEWS FLASH...............He posted the exact same questions ONE YEAR AGO. Got some help and like now, never followed up. So I'm no longer interested. Not a good responder.