The Stovebolt Site Forums The Shop Area The Electrical Bay carbon or stranded core plug wires?

Hey guys, I put a set of new carbon core plug wires on my '46 2 1/2 ton, and it wont start. I rebuilt the carb, new points and condenser, cap, coil and rotor also a new battery, ground and positive starter cable, everything works but no go! I've since been told that a stranded core set of wires will correct this problem, any ideas?

Scott

'46GMCanuck,

I think if everything worked the truck would start. It would be interesting if the wires were the cause, and pretty easy to find out. Pull a plug wire and hold it near ground..it should jump the gap. I would check everything I had done to the ignition system.

Stuart

Thanks for the quick reply, I have gone over everything multiple times, I have fuel (new pump) and rebuilt carb. I have spark at the points and at the plugs but still nothing. Will one ground strap from battery to tranny which is where it was mounted when I got the old girl suffice? or is another one required? I understand with these 6 volt systems that condition of wiring and grounds is critical?

Scott

Does it backfire or just nothing? If all the parts are good then I'd guess the wires are to the wrong plugs. doing the carb and electrical at once does complicate things. Sure you have gas in the carb?

Scott,

DennisM made some good points (no pun intended) about backfiring and ignition/carburetion work done in tandem. If it has fire to the plugs but absolutely no indication it is trying to start, I would think it has no fuel. If it has fire and backfires or pops, but won't start, I would run the firing order and make sure it is correct.

I am not a 6 volt person, but have heard these need all the battery poop they can muster. Make sure you have a full charge in the battery, and while a helper tries to start the truck, squirt gas into the carburetor...be careful of a backfire...you don't want to be extra crispy.

If you have proper ignition, the truck should try to start and run. Have you looked down the carburetor while working the throttle for spray from the accelerator pump.

Two of the three items needed to run the engine are in question..FUEL and FIRE. From what you have indicated, you have fire to the plugs.

To address the orignal question, I think the truck should run with the wires you have installed.

Stuart

I definately shouldn't do too much at once, but the damage is done. The accelerator pump is squirting fuel into the carb, there is spark at the plugs and the battery is juiced to the max. I made up a set of new stranded plug wires, a Guru at the local stovebolt parts store said carbon core no good so for $24 bucks its worth the ride and it still didn't start. I can smell exhaust and see puffs of smoke but no catch. Everything in the ignition circuit has been done except for the wires of ammeter to ignition key, ignition key to coil and starter to ignition key.

Scott,

When you did the points, did you take the distributor out? Is it timed properly and have the correct firing order. Now that you know it has fuel, the ignition system is the prime suspect. You said it has spark to the plugs and it appears it has fuel. It should work if the plugs are gapped to the proper clearance and the plug is firing when it is suppose to.

Check the coil and make sure the positive side goes to the key and the negative side goes to the distributor. If the points are set wrong, the coil won't have enough time to saturate which would give you a weak spark. I read that reversed coil wires result in 25% less output to the plugs.

After you try to start it, pull a plug and check its condition. It shouldn't be soaking wet, but it shouldn't be completely dry either. Be sure to check the timing..it almost sounds like it could be way retarded.

Was anythng else done to your motor when you worked on it...did it run alright before you tuned it up?


Stuart

Take a look at that condenser, had one new out of the box that drove me crazzier than I already am. Replaced it and all was good.

I have never taken the distributor out, when I bought the truck it was in. I set the points to .016" and the plugs to .035" I can see fuel in the carb when I give fuel at the carb, when I take a plug out it appears to be dry but I can smell exhaust not just raw fuel and I get puffs out the exhaust manifold where it doesn't seal too well, it should still start. The condenser might be no good but I am getting spark, the negative on the coil goes to the distributor and the positive to the ignition. The distributor is set one notch advanced it is very close to the middle of the scale which goes 10 degrees advance and retard the distributor also springs back on the vaccum advance so it isn't sticky. I appreciate your guys help we should figure this thing out it's only 60 years old, LOL.

Scott

What can I do to check the condenser?

Scott

Scott,

If the condenser were in question, I would just replace it. We are sort of back to the beginning on this again. As I think with the keyboard, here are my thoughts...

It must have ample fire at the plugs.

The plug needs to fire at the proper time.

There needs to be the proper fuel/air ratio present in the cylinder.

Did you find #1 TDC and make sure the distributor corresponded to that plug wire?

I am not sure there is such a thing as a specific coil for 12 volts, but I would make sure I had the proper coil.

Is the gas fresh...even with an improper mixture of fuel/air, if you have ANY spark, it should, at the very least pop. You said you are getting no popping, either through the carb or at the tailpipe.

If the timing is extremely retarded, you could actually be firing, but so near BDC that it appears not to be running.

You haven't said if it was running before..have you heard it run. If you have sufficient spark and adequate fuel and proper timing it will run, it is that simple. One of these items is missing
from the equation.

The mechanical considerations of adequate compression and valve issues haven't been addressed because we assume it did run before this problem. You will overcome..keep at it!

Stuart

I can't help, but I do have a question. If he is getting a spark at the plugs, wouldn't it follow that the condenser is ok.? I'm not much of a mechanic, but it seems that if the motor is getting gas, and there is spark at the plugs, then it would almost have to be a problem with either crossed plug wires, or the truck is badly out of time. Does that make any sense? Allen

Allen,

You got it!..sure seems like it should work doesn't it. I think a faulty condenser doesn't allow the coil to fully saturate which results in a low output. This is what the guru's here say. Scott indicates he has everything necessary for the engine to run, but it won't. Something has been overlooked and I am betting he will find it. All your points were excellent.

Stuart

Scott: Please let us know what the problem was when you find it. This one is a real puzzle, and I would really like to know what the problem is. Wish I could help, but I don't have a clue. Allen

These symptoms are the same ones that you get when the ignition wires are installed one post off. I would be checking to see that #1 is lined up when the steel ball on the flywheel is at the pointer.

Put on the old wires and see if it will start.

I had the same problem once, turned out I had the wrong "start-up" procedure. In other words, I was unknowingly flooding it. I left the choke open and opened the throttle about 1/4, cranked it over and it started. Try some different things with the carb. as far as choking, throttle position. But first I would try starting it with some starting fluid. Easy test to see if you have any fuel delivery problems. Not saying that it isn't an ignition problem, just another avenue to explore.

IT'S ALIVE!!!! all yours guys' advice came through for me, I went through everything today over again taking everyones advice to application. It started first crank and it runs very nicely the culprit was ignition timing apparently I am ignition impared. What I did in the end was lift the valve cover, crank over the engine till exhaust valve six was half way open and relocate my plug wires not one but two posts ahead, and it ran. Just like that I couldn't believe it, you guys are awesome Thanks.

Scott

Scott;
Another little trick I used on my ol'53 GMC was wiring a starter type push button from the battery post through a 5A. fuse to my button,to the input side of the coil. I mounted the button close to the starter button,and on really cold days I'd lay a knuckle acrodd the coil button as I was pushing the start button. That gave the coil full battery voltage while cranking the engine,and some mornings it made the difference between driving to work and waiting for a ride.
That works for 12 volt systems too. don't wire it to work full time or it could burn up your points.
Speed

Scott,

You beat the beast...


Stuart

Many thanks, I'm sure I'll be picking your brains again soon.

Scott