1939 Temp Gauge and Starting Problem..

[buick4547]

Well with the help of a good friend Tom, who also has a '39 as well as a "54 Super, we were able to install a new Temp gauge in my '39 Special. I replaced the one I mentioned on this forum a couple of weeks ago. The original gauge had "retired" for no apparent reason, except for old age. It was somewhat of a hassel to install the new gauge requiring Tom to wedge himself between the front seat and firewall while trying look up and behind the dash to unscrew the old pod which contains the temp and oil gauges, and then returning them to the backside of the dash after we had installed the new temp gauge in the pod. Tom was chosen for this annoying task because he is somewhat thinner than me - ample girth has its advantages at times! The new gauge works in a stellar fashion.

I do have another problem, however. At times the starter refuses to do anything at all. Then, at other times it performs well and as intended by Buick. There are those times when you flip the ignition switch on, press the accelorator and nothing happens. Then all of a sudden on the third or fourth try it works fine. And then some days I have no problem at all, each start is perfect. I suspect the starter switch at the carbureator may be the culprit because when it doesn't start, as a last resort, I can place a jumper wire via alligator clips from the positive side of the battery to the left side of the switch, (driver's side), and the starter turns over as it should and the car starts.

So, what do you think? I'm sure Grant or Danny will be able to diagnose this situation easily.

As always, thanks for your help,

Jim

[Guest Grant Magrath]

Thanks for your optimism Jim!

Sounds like the vacuum starter switch on your carb is a bit sticky. That, combined with a brittle diaphragm. You can take it apart and clean out the vacuum passages with some carb cleaner, but the long term solution is usually a new diaphragm, and they can be hard to find. Keep a 4" piece of wire in the glove compartment to bridge the terminals if it decides to give up on you while you're out somewhere.

Cheers

Grant

[danhar1960]

Thanks for your optimism Jim!

Sounds like the vacuum starter switch on your carb is a bit sticky. That, combined with a brittle diaphragm. You can take it apart and clean out the vacuum passages with some carb cleaner, but the long term solution is usually a new diaphragm, and they can be hard to find. Keep a 4" piece of wire in the glove compartment to bridge the terminals if it decides to give up on you while you're out somewhere.

Cheers

Grant

Grant's 4" piece of wire to bridge the terminals on the carb switch to test it is a good place to start to confirm if it is in fact the carb switch. If you have a WDO Carter carb there is no diaphragm in the switch. They dismantle easily to clean up the contacts. If it's not the switch let us know.

Danny

Edited April 11, 2012 by danhar1960 (see edit history)

[buick4547]

Thanks for your optimism Jim!

Sounds like the vacuum starter switch on your carb is a bit sticky. That, combined with a brittle diaphragm. You can take it apart and clean out the vacuum passages with some carb cleaner, but the long term solution is usually a new diaphragm, and they can be hard to find. Keep a 4" piece of wire in the glove compartment to bridge the terminals if it decides to give up on you while you're out somewhere.

Cheers

Grant

Grant thanks, but now a follow-up Question: Is there a diaphram type of starter switch, and is there a Bakelite type of starter switch, (2 different types of switches possible on a '39 )? Because I think mine is the Bakelite type without a diaphram . Or have I confused you by the question? I visit the state of confusion quite often myself.

[Guest Grant Magrath]

Jim, as Danny pointed out, there are two types of carbs for a 39, Carter and Stromberg.

Here's a pic of our Stromberg.....

Our local mental institution had a man who thought he was an American town. Last I heard, he'd worked himself into a state!

Cheers

Grant

[danhar1960]

Jim,

If you confirm that it is a Carter, they are not that hard to remove and clean up. They usually just get junked up and stick. Sometimes the crack and or break. If there is something majorly wrong you can buy a new one.

This bloke has "repair kits" Not sure what that includes or involves.

Carter Carburetor Starter Switch Kit

Danny

[FLYER15015]

Hey Grant,

Your Stromberg looks just like mine.

Do you suppose one could hook up a permanent jumper at the carb switch ? Made of old looking wire of course.

Would it interfere with anything after she starts or drain the batt at shut down ?

Just asking for the benefit of all those checking this thread in the future.

Mike in Colorado

[Guest Grant Magrath]

Hmmm. Good point Mike. I seem to recall earlier threads on starter switches where the ground is taken from the generator , but when the engine fires up, the polarity is reversed, and that the starter switch is redundant, or something like that. The starter switch circuit is only live when there's no vacuum from the engine, so if you did bridge it, the ignition switch should take over as the starter from the accelerator pedal. Other than that, re batt drainage, I don't really know for sure, but I wouldn't think so. But if you stall...........!

Cheers

Grant

[FLYER15015]

Grant,

So you are saying that the vacuum switch on the carby needs to "connect" those two wires to make the starting circuit hot ?

So if they are always connected (via a permanent jumper) and if you pressed down hard enough on the gas pedal, you could conceivably engage the starter (at some really high rev's). Not a good idea !!!!!

You try it first..... and let us know how it works out for you........

Mike in Colorado

[danhar1960]

For the benefit of anyone that checks this thread in the future :), permanent jumper :eek: = really bad idea !!!

A couple of possibilities for disaster :

Generator fails for some reason, grounding relay in the regulator closes and the starter would engage.

Fan belt breaks, same effect as above.

If the grounding relay in the regulator fails, again the starter would engage.

Any of these may explain 1 or 2 flywheel ring gears I have. :)

If the carby switch is a problem or of concern I would suggest the old hidden push button as a temporary and/or even a permanent option.

Danny

[Ben Bruce aka First Born]

Danny has it right!! The push button switch will serve the same function as the carb switch, the same as the TEMPORARY jumper. It was done a lot back in the '50s.

Just UNHOOK both wires at the carb switch, connect another wire to each, run both NEW wires through the firewall to a convenient , easy to reach spot on the bottom of the dash and connect to the push button switch.

Ben

Edited April 13, 2012 by First Born (see edit history)

[Guest Grant Magrath]

Grant,

So you are saying that the vacuum switch on the carby needs to "connect" those two wires to make the starting circuit hot ?

So if they are always connected (via a permanent jumper) and if you pressed down hard enough on the gas pedal, you could conceivably engage the starter (at some really high rev's). Not a good idea !!!!!

You try it first..... and let us know how it works out for you........

Mike in Colorado

I don't think it would work quite like that Mike, but I see what you mean with the decrease in vacuum at WOT. If the switch terminals were bridged, the accelerator would be taken out of the equation due to the polarity reversal of the generator. But Danny raises the best argument why you shouldn't! GM always have their reasons for things!

Cheers

Grant

[FLYER15015]

I think Danny has it right.

Permanent jumper = a really bad idea !

When needed, I'll go w/ the Button.............

Mike in colorado