general ignition system ?s

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Dec 1, 2002 | 02:29 PM

gtex

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Joined: Apr 2001

Posts: 6,175

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From: Texas

general ignition system ?s

All,

I'm working on another vehicle besides my 69 F250. I had it running pretty good after a carb rebuild and I verifed that it is getting fuel. So my suspect is the ignition system. It is an older vehicle, early 60's. 12V system.

It ran good for hours after the carb rebuild and this was probably the longest it had run after sitting for many years. Recent progression of events:

1. Started, warmed it up and ran it for a while.
2. Started to actually drive it down the street, killed it at the first stop sign, driver bad use of clutch.
3. It would start but not keep running.
4. I limped it home, and it would usually start cold and then quit after a while.
5. Now it won't really get going at all. There are hints of firing but not enough to keep it running.

There is 12V going to the coil. What should I see coming out of the coil as far as voltage? The cap, rotor and points look pretty good. I'm sure they were replaced not many miles ago. Is pulling a plug and holding it against the block the best way to determine if I have fire? Any other basic ingition trouble shooting ideas?

FYI, the plugs looked pretty dirty. As I would expect after sitting.

Dec 1, 2002 | 07:27 PM

Franklin2

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Joined: Jan 2001

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From: Virginia

general ignition system ?s

You can take the wire out of the center of the dist cap, or select one of the sparkplug wires and unplug it. Take a screwdriver and stick up in the end of the wire, and holding the screwdriver by the handle, place the metal part of the screwdriver close to a good ground. While somebody cranks the vehicle, a strong blue spark should jump from the screwdriver to the metal ground(engine block is best).

If you are getting spark, then I would start suspecting the fuel system. I know you just rebuilt the carb, but a little rust flake or piece of dirt from the fuel system could have got in the needle of the float and made it stick. Try to get it running again, and then take a flash light and look down the carb throat. If you see liquid fuel dripping in the carb, then it is flooded and the float is probably stuck open. Sometimes you can take the plastic part of the screwdriver and rap on top of the carb to dislodge the dirt. If you keep having problems, then you will probably have to pull the gas tank and clean it.

Dec 1, 2002 | 08:46 PM

gtex

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Joined: Apr 2001

Posts: 6,175

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From: Texas

general ignition system ?s

Thanks for the info, I'll probably tinker more with it this week. I need to get this one running so I can do the body-off work on my 69 F250.

Dec 2, 2002 | 01:09 AM

big_country_ch19

Freshman User

Joined: Nov 2002

Posts: 48

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From: Kings Island (north of Cincinnati)

general ignition system ?s

I know this will sound crazy but I has the same problem with my 72 LTD with the 429/C6 and posi 9". Come to find out, after my car sat for about 1.5 years in the driveway before I started trying to drive her daily, the muffler had retained moisture and started to fold and buckle. When the engine got warm the muffler got hot and bowed even more restricting the exhaust flow. In short: when the muffler got hot the engine shut off till the muffler cooled down. I took me selling my baby for $400 to find this out.

Hope that helps, and let us know what you find. Jack

Dec 2, 2002 | 02:26 AM

Polkat

Elder User

Joined: Aug 2002

Posts: 662

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From: CA

general ignition system ?s

If you don't have spark during the above test, check that the points are clean and gapped correctly. The point end faces can build up rust after a while, and if there's oil in there the whole setup can get gummy. Don't try to read the output of the coil with a little voltmeter, it will fry the meter! If you suspect the coil swap it with a good one as a test. Another thing you can do, since you said you have 12 volts at the coil, is remove the negative coil wire (the one going to the distributor. Then take a length of wire with an alligator clip at least on one end. Remove the heavy coil to distributor wire at the distributor and prop it's metal connector within 1/2" of the block. Now clip the length of wire with the alligator clip to the coil negative side. Turn on the key and touch the other end of that wire to the block. Each time you do, you should get a spark at the end of the heavy coil wire to the block.

If you do, the problem is somewhere in the distributor points setup. If you don't, the coil may have open windings.

Dec 3, 2002 | 03:55 AM

wayne_j

Senior User

Joined: Apr 2002

Posts: 406

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From: cedar rapids usa

general ignition system ?s

I hate to say this, but it sounds like you have tossed the timing chain. Have you tried the old "static method" to time the engine? The static method involves bringing the engine up on compression stroke by hand, then allign the timimg marks on the balancer and timing tab. Next hockup your timing light to the number one plug wire and turn the cap till you see the flash.

This will put the timing right for idel without vaccum advanced. It will also tell you if your coil is firing the plugs. If your cap seems like it is way out of place I would suspect that the timing chain has streched beyond hope. You can also pull the cap and have a buddy turn the engine over as you watch the rotor. If it jumps around you know the chain is jumping teeth.