1956 6219 Electrical(?) Issue

[RMcGrew]

I have had this car since 2005 and for the most part she has run without issue.
The problem :
The engine turns over without a problem.
The engine idles fine.
When you increase the revolutions to almost 1/2 of full throttle (I have no idea what revs that is) the engine simply cuts out and dies.
My mechanic has diagnosed this and replaced the coil, the regulator, battery and cables, all for logical reasons but the engine still dies.
The next to go is the generator for rebuild, and after that probably the solenoid and distributor as we start frantically throwing parts at it.

What works :
Lights - lower and high beams
radio
one fog lamp
map light
heater fans,cigar lighters
turn signals
horn
trunk and license plate lights.

What does not work :

electric antenna (never has)
front speaker
dome light
one fog lamp (right)

That is what I know of the problem.  Anyone have any ideas what is going on? This has stumped us.

Thank you.

[Glen]

The first thing to change is the mechanic.  If the car starts and idles OK the battery, cables, regulator and solenoid are all good.   

[John Washburn CLC 1067 Sadly deceased.]

Really can't argue with Glen, but one might check out the distributor.... Something does not sound right, check the advance to see if something shorts out when it advances (both vacuum and centrifugal).

John Washburn

[J. Gomez]

Randal,


To add to John's comments..!

You and your mechanic have replaced the most logical items (electrical) that could be the culprit with the issue. If the engine just cuts-off as you describe at just about ½ throttle there still the mechanical aspect of the ignition side or a combination of both electrical and mechanical.

When the engine dies is there +9 â€" +10v voltage present at the “+” side of the coil, probably there is just an option to check.

On the “-“ side of the coil you will get a pulsating negative polarity from the points, check and see what happens at the transition point when the engine idles and dies after you rev it.

There could be problems with either the points or condenser causing arching at that high speed shorting the “-“side of the coil.

On last note there is a ground strap at the distributor breaker plate which goes under it and connects at the vacuum advance holding screw, make sure this connection is solid.

Just a few options to check before you trough more $$$ while trying to resolve your problem.

Good luck..!

[Glen]

I agree the distributor would be a good place to look but the solenoid?  The guy either does not know how to work on non computer cars or he is just padding the bill. 

The solenoid in only used during starting, how can that have any effect at half throttle.  The battery and cables are strained most during starting, the only way they can cause the problem is if they disconnect.  So you would be looking for a mechanical situation where half throttle disconnects the ignition. 

The generator and regulator are not likely to be a problem either with one exception, I have seen a car where the regulator went bad and the voltage went so high (80 volt range) the ignition cut out, but that had an electronic ignition. 

These things can be checked by monitoring the voltage as the throttle is opened up.  If the voltage cuts out or goes sky high then you look at the generator/regulator, don’t rebuild them to see if it fixes the problem. 

This is what we called easter egging or hunt and peck.   The guy’s only out with me is if he had reasons other than fixing the stated problem.  Such as the cables were in bad condition.  If all those parts need replacement before the problem cropped up then he can be excused for doing that work.   

I detest mechanics that replace parts because they can.  You lose a lot of original parts that are replaced by generic parts from China.  Not to mention the extra cost. 

[57flw]

Randal,

Have a look at the Ballast Resister.
It is there to provide 12 volts at cranking and starting the engine and then filters the voltage down to around 9 volts to help prevent the coil from getting too hot.
If it fails it will provide the same symptom and fault that you are currently showing.

You do not have to spend more money on the hit and miss method of diagnosing. There is a simple test you can do.

All you need is a short length of wire to use as a jump wire. Connect it as shown in the photo below.(Jump Wire is RED)
Test the car as normal, with the jump wire in place.

If it performs well then you can spend the extra money with confidence and replace the ballast resister. If the car still plays up remove the jump wire and let the forum know you still have problems.

I am assuming your 56 is similar to my 57.

Hope this helps.

Ken Francis

[Caddy Wizard]

Check the main jets in the carb.  They take over from the idle circuit and the part idle circuit at a certain throttle position (up to a certain throttle angle, the idle circuits are operating and at a certain point they completely cut out).  So plugged main jets would do this.  Also, check the fuel pump pressure and fuel level in the carb.


Also, check the exhaust to make sure it is not restricted.


Take a timing light and check to see if the timing light signal dies at a certain point as you rev it up.  If so, then you know you have an ignition or electrical problem.  If not, then it could still be electrical or ignition, but perhaps not (and see item 1 or item 2 above).


Art Gardner

[RMcGrew]

Thank you all for your responses.  Here is what we found.

Two inter-related issues.

The generator was on its way out. After all the new parts we found it was generating less and less until it finally stopped. It's dead. That in and of itself did not cause the car to keep dying when the engine was revved up. Originally we thought it was a fuel problem, and as it turned out, it was. We tested flow from the tank up to the carb. Finally the carb showed it was not providing the normal flow under load. It  was only using one jet.  We took the bowl cover off, cleaned it and the needles, then reassembled it. The car started and ran beautifully. Then the carb failed, and started leaking from the bottom.

Up shot... we need to find a rebuilt generator and a rebuilt Rochester 4 barrel (although this one is a Carter).

I'll see if Jonathan can't straighten my confused rambling out. Im pleased because I get to get a new gen and carb.  Im weird that way.

So thanks again guys.

[57flw]

Randal,

Great to see you have ended up with a positive result.

It is always interesting to see how many problems that can cause our cars to not perform well and all this without the problems caused by electronic failure.

Great result now go ahead and spend some more money. The economic crisis over there needs you.

Ken