'55 Tune-up / Timing light weirdness

J

johnnyknownothin

Guest
I just bought this '55 Special and have been in the process of tuning it up...and it's been an ordeal...sometimes the simplest things end up being so complicated and frustrating...anyway, the ignition sys. on this Buick wasn't in the best shape when I got it -- mouse chewed sparkplug wires, fouled plugs, leaking ignition coil, dirty points and dist. cap, rotting battery leads, the timing was more than likely off -- and consequently it ran like crap -- stalled when given gas from a start, poor gas miliage etc.

So, I decided to replace all of the necessary elements -- new battery, new battery leads, new ignition coil, new ig. coil resistor, new plugs, new wires, new dist. cap, new points, new condenser, new rotor.

I took the distributor out (after setting the engine to TDC) to clean it and replace the parts more easily and put it back in without much difficulty. I replaced the coil and everything else and, getting ready to for the timing check, disconnected the vacuum advance. The car started just fine -- a little rough -- but I thought I'd fix that when I set the timing. Right? Nope.

The timing light (inductive type) wouldn't work. So I checked the timing light on another vehicle and it worked just fine. So, I checked the battery voltage and found that the battery had run down in the week that I'd been working (off and on) on the car (even though it still had enough juice to crank the car). So, I got the battery recharged. Hooked up the timing light again... still wouldn't work. Checked the battery voltage again...it's at 12.5 v -- so it's not that.

Could it be the generator? Could there be somthing wrong with the new parts in the circuit ... the new ig. coil resistor? Is it still, perhaps, the battery?

The car runs -- not great -- but better than before. But I really need to set the timing properly before I move on to anything else.

Does anyone have any idea what the hell could be wrong here?

This is driving me up the wall. No pun intended.

Thanks guys,

jkn
'55 Special Sedan
 
Interesting, did you move the pickup to another spark plug wire? Maybe number one is not firing? I have used my inductive timing light to time cars with 6 volt systems by powering the light with a 12 volt battery. That would makes me wonder if the light is getting a signal.
 
Yep. I've tried the pick-up on every wire including the wire from the dist. to the ig. coil. No luck. I figure at least a majority of the cylinders must be firing since I can start and drive the car.

I'm thinking that there's got to be something wrong with the power being supplied to the timing light.

jkn
 
Johnny,

Check to make sure the engine and battery are grounded to the frame or firewall somewhere. I don't know if that would have anything to do with your problem, but they should be grounded.

Some older cars used a six-volt system. My knowledge base only reaches back to 59, so I am not sure what system you have. If you have a six-volt system, you need to power the timing light with 12 volts. Perhaps you can move a newer car closer and use that battery for the power. I could be way off here, but it was worth a shot.

Happy New Year from the Frankenbuicks!


------------------
Steve B.
GSCA #2173 (1986)
67 GS 525 Stg IV
66 GS Convertible
65 GS HT
63 Riv
 
It's a twelve volt sys. on the '55. And the battery is definately grounded to the engine block. The idea to check the timing using another battery is a good one; and I'll do it if only to try and get the timing sorted out -- but still, something is very wrong here.

There's a ground inside the distributor -- perhaps I wired it back wrong -- in the shop manual it seemed to go from the vacuum advance to the distributor housing and that's the way I wired it -- can someone confirm that this is right? That'll at least rule that out.

I hope this battery is holding its charge (I'm going to check that and the voltage being supplied to the battery from the generator while the car is running today) -- if it's not holding enough, I might have to entertain the posibility of getting a new generator.

Keep the sugestions coming, even if they seem obvious -- everything is helpful and appreciated.

Thanks.

Happy New Year to you too Doc. F.

jkn
 
JKN,

Did you set the point gap to .016 when you changed them? That is the preliminary setting recommended for the later Nailheads and yours. Maybe there is weak spark from not having them open far enough. As recommended in Bob's timing article, the dwell needs to be set before the timing anyway: http://www.buicks.net/shop/reference/engine_timing.html .

I know you said the rotor, points, coil and condenser are new, but it couldn’t hurt to try the old ones and see if there is any difference.

Lastly, did you gap the plugs? Maybe the gap is too small and also contributing to weak spark. There are some tune up specifications on this site for the 53. http://www.buicks.net/shop/tuneup.html . The second engine listed for 53 (all others) should have about the same specifications as yours (same engines until 57).

It sounds like your ground runs from the points platform plate to the distributor housing. That is just what it needs to do. I am out of ideas for the time being. I hope you get it soon.
 
Yep, checked the point gap (had it set to .16) and gapped the spark plugs to .032.

And things get stranger still. Today I hooked up the timing light to a 12v on a buddies car and put the inductive pickup around the #1 wire on my car...nothing...then proceed to put the pickup on every other wire ... if I wiggled the wires or moved them to where they were just touching the top of the spark plug, then sometimes the timing light would activate, sometimes not, and not for any consistent period of time or with the wire in a consistent position. I checked all of the dist. cap terminals -- everything was solidly seated.

I am even more baffled now than before. How can the light work sometimes and not others -- and why would it work (which it did more often -- but still not consistently) with the spark plug wire almost all of the way unplugged from the spark plug?

The battery has dropped in voltage too -- down to 50% (I had it fully recharged yesterday -- checked it myself too, when I brought it home). It'll still crank the engine though. The voltage from the generator to the battery while the car is running is 11.9v -- I always thought that should be at around 13v -- could this be the cause of the problem? Perhaps the parts store gave me the wrong resistor for the ignition coil (I'm going to put the old one on there and see if I notice the difference).

I feel like I'm the butt of a candid camera skit.

jkn
 
A little rambleing here!
I can sure see why your desperatly looking for help! It's not easy to see where to start with your list of whows... I wonder if you should perhaps have a look at your battery and voltage and clear that.

With a generator you will have low voltage until you rev it up a bit, then you should see the voltage rise as it begins to put out.

Your battery should not loose that much power overnight.

I wonder if you problems could all be a voltage problem. As you pulled the wire away from the plug, you essentailly made it harder for the coil to fire. On your + side of your coil when cranking you should have full battery voltage, when you release your key, you should have reduced voltage through your resistor. Why don't you run a hot wire from your battery to the + side of your coil and see if that eliminates the problem. When you do this you are being hard on your condenser, but you will be increaseing the running voltage to the coil by bypassing the resistor. If you run it too long in this fashion you will pop your condenser and have no spark at the points. But you shouldn't have any trouble with a few minutes for testing.

[This message has been edited by bob (edited 01-02-2002).]
 
A couple of other thoughts; for radio noise supression, the 55s used a resistance built into the distributor rotor. This should measure about 10000 ohms. Spark plug wires having built in resistance did not come out until a year or two later. If you are running resistance spark plugs wires instead of copper, the current to jump the gap in the plug would be about 1/2 normal. Using resistor type spark plugs would do the same thing. Maybe this is enough to make the timing light weak.

To see if something is draining your battery overnight, pull the + lead of the battery and attach a DC ammeter between the battery post and the lead. With everything off, there should be no current draw except for a small fraction of an amp for a clock or add-on radio/tape deck etc.
 
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