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My 66 with the 352 quit running this morning. A month ago I noticed after I start the truck then put it in neutral and release the clutch it stalls. It will do this until warm. Today same deal. I got it running then drive it about 10 minutes to the firehouse and back home. I left the truck running while I went to grab a couple of things in the house. The truck stopped running. I went outside to turn the key off. I got back in the truck and it only tried to start twice. After those two times it would turn over with no fire. I seem to have lost spark. Doesn’t tried to run now. I’m thinking a bad coil? Cap and rotor look new...
Before you go throwing parts at it, find out if you do or don't have spark at the plugs, pull the plugs and see what they look like, black and sooty, oily, clean and dry, hook the wire to it, lay it on the engine and crank it over watching for fire, it could be a problem with the carb, or the timing chain is worn a lot causing slow timing.
Every four stroke engine needs three things to fire: Air, Fuel and Spark.
Do proper diagnosis. Check for air. If you're reading this, you likely have air. Check.
Do you have fuel?? Using starting fluid spray is OK, so, Check.
Do you have power at the coil??
Do you have ground at the points??
Do you have spark at the plugs??
Proper diagnosis. It's a 'thing'.
I’m going join the pot and bet with cosmo; if you do not understand the systems well enough to diagnose/troubleshoot then you are just changing parts (not an economical solution). I was a mechanic for 15 years - nothing was as deflating as replacing a part only to retain the same problem. It is EXTREMELY difficult to diagnose a problem via forum chit/chat. Take the advice to heart and spend a bit of time processing and understanding the relevance of advice given. A basic understanding of what you have and how to troubleshoot is vitally important when relying on old iron - although having deep pockets and alternate transportation can easily offset that predicament. I agree with the other suggestions that ignition is the most likely suspect. Good luck and have fun learning.
The Shop manual has a pretty good troubleshooting chart list if wondering where to begin. "Engine Runs Rough" and a bunch of things to check in logical order. "Engine Fails to Start" etc.
How long were you away from the truck?
One "feature" of a points type ignition system - if the ignition key is in the "RUN" position - but without the engine actually running - the contact points will eventually burn up, if they happen to be closed.
How long does that take? I dunno, guessing maybe 10 or 15 minutes would be enough? The ignition coil too will also get real hot because of the continuous current flow, and eventually spooge the magnet wire windings, & oil.
Thank you all for the replies. I honestly forgot about the repair manual which I do have. I’ll check it out tomorrow. I’m pretty handy with things once shown how. Hopefully I can follow the manual. I was just wondering if anyone else had a similar issue like I had. I’ll keep you folks updated on what I find. I also honestly know nothing about points or ignition systems...
Yes, it's very straightforward and kind of cuts straight to the heart of the matter. The first thing is likely pull the coil wire from the distributor and hold the end about 3/8" from a head bolt and crank the engine over. Look for a strong blue spark to ground. A thin yellow spark is no good.
It might be the case where there is no spark from the coil, therefore the issue is somewhere in the low tension or primary ignition circuit components or wiring.
Or, you might find that while there is a good strong spark from the ignition coil wire to ground, there is no spark at a grounded spark plug in the open air. That would then point to an issue inside the distributor cap, rotor, or plug wires or even a spark plug. The troubleshooting diagrams are good because they really save time by a process of elimination. Find out what actually works, keep checking downstream from there till the trouble reveals itself.
Good afternoon folks. It’s been a while since my baby was running. I checked it out a few times with no luck. I changed out the coil and condenser in the distributor and still no luck. I had three different buddies that were supposed to come look at it with me and they all bailed on me. So today my wife and I went out and started fooling with it for a bit. I checked the power going to the + on the coil. Then pulled the cap and had spark at the points. Not sure if the cap was sparking though. As I was about to give up I saw two of the three wires were cracked and corroded. For likes I cut them, spliced them, and wire nutted them. Wife turned the key and she fired right up. Really made no sense to me. One wire was white with red stripe and went to the oil filter. The other wire was red with a white stripe and went to a terminal on the block. I was thinking that was a temperature sensor. So can some explain to me what this does? Are they a safety switch?
The oil pressure switch and temp switch have nothing to do with the spark. The engine sat for a while so one possibility is that something that was over heating cooled off. That is a failure mode of canister type coils if the oil has boiled off. Keep looking for the real cause.
Check the wiring going to the coil, maybe you have a loose connection or wire going bad. You may have wiggled it while working on the other wires a got it working.
