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drnittler
01-30-2007, 01:09 PM
Hello: For my 61 lark 6 cylinder, I could use some help. A while ago, it slowly died. After investigation, I learned that plugs 1 and 5 have weak fire and 3,6,2,4 have none. I have changed points, condensor, rotor and cap, checked electricals and fuel. I am led to believe that the distributer is not connecting to the leads under the cap. The rotor turns freely, nothing is binding and I have not removed the distributer to change the timing. Can the timing jump or the distributer get off center? Any advise is appreciated.
Thanks...

David G. Nittler

skyway
01-30-2007, 06:22 PM
Yes, the distributor bushings can go bad and let the shaft get off kilter, but that should also result in contact/scratching/gouging marks inside the distributor cap, and on the rotor. If timing has jumped, then your cam gear is on the way out. I'd verify static timing per the shop manual, TDC on #1, and all that.

I see that you've checked the electricals, but have you verified good blue spark at the points, and poor at the plugs? If so, checking resistance/continuity in the plugs, plug wires and connectors is in order.

If spark at the points is not good, then look for a short in the primary circuit. If this is an overdrive car, check the cut out circuit too. Finally, I guess there is always the coil to consider.

whacker
01-30-2007, 07:28 PM
In the list of parts that you have replaced, I don't see plug wires? It could be something that simple, especially if you have tested everything else.

Roscomacaw
01-30-2007, 07:40 PM
Well, first off, the distributor doesn't actually "connect" to the wires other than to realize that the wires DO plug into the cap. But as the rotor whizzes around inside, it provides a spark to each contact it passes. The spark jumps the gap to the contact it's passing - there's no physical connection of rotor and contact.
Have you done a compression check of the individual cylinders? We need more specific information as to HOW you checked fuel and electricals and what you observed at each check.
Unless the points are shot or the distributor cam that operates the points is wobbling horribly, I can't fathom having spark (however weak) on 1 & 5 and not the others.
The timing CAN jump out of time, but even then, if the distributor turns, it ought to cause fire at all six plugs. It wouldn't RUN right, but they would fire nonetheless.

Miscreant adrift in
the BerStuda Triangle
http://images.andale.com/f2/115/106/906179/2006/12/7/truckonhill3.jpg

1957 Transtar 1/2ton
1960 Larkvertible V8
1958 Provincial wagon
1953 Commander coupe

John Kirchhoff
01-30-2007, 09:25 PM
You might check the points gap again. There's the possibility that some of the lobes are worn more than the others. I could see the points being too close and the lobes on 1&6 being just a bit taller either due to less wear or just machining differences when new. To check the points and coil together, remove the distributor cap, turn the engine over until the points are closed, turn the ignition on, the wire that runs from the coil to the distributor cap, remove it from the cap, hold that end maybe a quarter of an inch from the engine block, open and close the points with your thumb and you should get a healthy blue spark. If you do, you can rule out the points, condenser and coil.

If you don't get a spark, disconnect the small wire from the coil terminal that goes from the distributor cap to the coil and attach a piece of wire with a bare end. With the ignition on touch that wire to the block and you should get a spark. If not it's probably the coil, if you do, it has to be in the points or condenser.


I doubt it is the point's contact area, coil, condenser or rotor since their performance is common to all the plugs and wires. I'd be looking for something that is particular to each plug such as the plug wire, connections in the distributor and distributor cam lobes.
Even if the timing is off, that won't stop the plugs from sparking, they'll just be sparking at the wrong time so you should be able to rule that one out.

drnittler
01-31-2007, 08:58 AM
Thanks to all for the replies. This problem was a sort of three day condition..(Notes: I rebuilt the motor and the timing gear was new and have only 2500 miles on the rebuild; and the plug wires are equally old but were ok before all this happened), What happened is this: one day I drove it and it was getting sluggish with no acceletation, the next day I could bearly start the car but it would idel, the next day it cranked only. I went through electrical and fuel stuff, The coil, rotor, and cap are new. The distributer shaft is not wobbley, grinding, slipping or whatever, and the timing was lined up. The engine will crank with no dragging, oil comes up to pressure. Any more thoughts are appreciated.

David G. Nittler

Bill Elbert
01-31-2007, 09:31 AM
David, This may be a remote possibility, but I went through a similar problem a couple of years ago with my Champ equipped 46 M15. The truck would not start after an all night sit, it had been running great up to this point. I was sure it was an electrical problem and checked and replaced many ignition components. After these changes had no effect, a friend mentioned he had had a similar problem a few years before, it was the choke butterfly stuck shut. I checked mine and sure enough that was the case. I had been sure it was an electrical problem because just as in your case, it seemed I had a weak spark. I fixed the Carb and no problems to this day. I hope it's something as easy as this.

Bill Elbert
http://farm1.static.flickr.com/160/337006150_f69e452789_m.jpg
59 4E11
58 Champion
57 3E11
48 M16
46 M15
41 M5

drnittler
01-31-2007, 09:50 AM
Thanks for the help. I have already checked the carb and open the valve ie the choke. I am at a loss. Dave

David G. Nittler

John Kirchhoff
01-31-2007, 12:35 PM
Considering the progression of symptoms during the three days, you may want to consider the possibility of a bunch of rust and crud in the fuel filter or carburator. I had a motorcycle which had a rusty tank. I cleaned the rust out but it continued to rust anywhere air was present. The rust particles were so fine they'd get through the in-tank filter and the in-line filter I installed and plug the carburator jets. Finally had to coat the tank. Don't know if you have an in-line filter, but if so you might change it. If you pull the carb apart and find extremely fine rust in the fuel bowl, you might take a look at the gas tank and coating may be in order.

drnittler
01-31-2007, 04:02 PM
Tanks I checked all that two, even took the carb apart thinking the float was stuck. The fuel filter is new and clean...

David G. Nittler

Roscomacaw
01-31-2007, 04:32 PM
OK, what about the starter solenoid? Your solenoid has 2 little wires going to it (not counting the cable from the battery and the cable to the starter). The little white wire effects a momentary bypass of the ignition resistor (or resistor wire as the case might be) to provide a full 12 volts to the coil while the starter's turning. If that wire were disconnected, had poor connectivity at the solenoid OR the coil - OR the internal solenoid connection that feeds the little "I" terminal wasn't passing current when the solenoid's actuated, you'd get a very weak spark while cranking.[B)]

Miscreant adrift in
the BerStuda Triangle
http://images.andale.com/f2/115/106/906179/2006/12/7/truckonhill3.jpg

1957 Transtar 1/2ton
1960 Larkvertible V8
1958 Provincial wagon
1953 Commander coupe

John Kirchhoff
01-31-2007, 10:00 PM
Mr. Biggs might be onto something and got me to thinking. When you were checking the spark at the plugs, where you or someone else inside the car turning the engine over with the ignition key or did you have the key in the run position and energize the solenoid from under the hood? I had a Tempo that would crank over, fire up but as soon as you let the key return to the run position, it would die. Ends up it had a bad connection in the run wire in the wiring harness along the steering column and letting up on the key cut the ignition. If you tried starting it before with the key, try turning the key on, run a hot wire from the positive side of the battery and touch the terminal where the red wire is on the solenoid. That should crank the engine over without having electricity go through the start portion of the ignition switch but it will still draw juice through the run position. If it still has little or no spark, try running a hot wire from the positive battery terminal to the ignition coil, crank it over and see if that makes any difference. the key does not need to be on because doing that will totally bypass the ignition switch, all wiring and electrical connections between the coil and the battery. While you're at it, check and make sure the coil wires are the correct polarity. The - terminal wire goes to the distributor and + is the energized side. If you still have no spark, remove the distributor cap and check the spark by manually opening and closing the points as I outlined earlier. Still none and manually ground the coil as I also said. I'm sure the problem itself isn't that complicated, but finding it can be. All you can do is start at one end of the system and eliminate one thing at a time and sooner or later you will isolate the problem. It doesn't matter if a person is a novice or an expert mechanic, the process of elimination is the only way to find the offending part.

drnittler
02-01-2007, 08:49 AM
Thanks for the replies. I was starting this from the solenoid, with the key on inside. I did replac ethe ignition switch because it did not have any spring to it. I could always start it from the solenoid...When I put the switch in white wires black trim went the ACC, Black with green trim ign and others to bat. It this correct? Thanks..

David G. Nittler