1956 Generator

[Lexi]

Just had my generator rebuilt for my '56, and also purchased a new voltage regulator. Previously the battery was being over charged, (15 - 16 volts at idle). The new voltage regulator is said to be 'factory preset', but at operating temp, at idle (around 550 rpms), all I get at the battery now is about 12.6 to 12.7 volts on average, sometimes lower. Battery is 3EE style and bought new and installed with rebuilt generator and new voltage regulator. Shop manual specs seem to say aim to adjust regulator to 14.5 volts. What has been the case with anyone who has recently done work on their charging system? Re builder said over the phone that he thinks the new regulator can be adjusted like the original. This morning it was cold and after a short run, battery grunted before the car would re-start, (takes a few more amps to overcome a warmed up engine-though car is not running 'hot'-is normal). I think what may be happening is that my new battery has been receiving a nominal charge but not deep enough to adequately maintain it, over time. Generator was polarized prior to first running engine after rebuild. Red 'idiot' light now on most of the time at idle. Thanks for any comments and suggestions. Clay/Lexi

[carguyblack]

Having the same thing happen with my fresh rebuilt engine. Restored carb was on the car before the rebuild and did nothing to it. Timing has been set on the new engine and the idle is very low. The big air screw visible by the linkage doesn't make it idle up faster and I can't get more speed by adjusting the 2 front screws on the carb now either. Consequently, my generator light is dimly lit all the time as the car idles.
Should I change the timing to my ear and speed up the engine that way, readjusting the needle adjustments later? I'm at a loss as nothing on the carb changed but it sure runs differently and slow, almost to the point of killing. Any suggestions?
Thanks,
Chuck

[J. Gomez]

Just had my generator rebuilt for my '56, and also purchased a new voltage regulator. Previously the battery was being over charged, (15 - 16 volts at idle). The new voltage regulator is said to be 'factory preset', but at operating temp, at idle (around 550 rpms), all I get at the battery now is about 12.6 to 12.7 volts on average, sometimes lower. Battery is 3EE style and bought new and installed with rebuilt generator and new voltage regulator. Shop manual specs seem to say aim to adjust regulator to 14.5 volts. What has been the case with anyone who has recently done work on their charging system? Re builder said over the phone that he thinks the new regulator can be adjusted like the original. This morning it was cold and after a short run, battery grunted before the car would re-start, (takes a few more amps to overcome a warmed up engine-though car is not running 'hot'-is normal). I think what may be happening is that my new battery has been receiving a nominal charge but not deep enough to adequately maintain it, over time. Generator was polarized prior to first running engine after rebuild. Red 'idiot' light now on most of the time at idle. Thanks for any comments and suggestions. Clay/Lexi

Clay,

I would not trust the new VR to be adjusted per the Cadillac specs, it may be adjusted to a nominal tolerance per the manufacture since those can interchange with several models.

I would suggest to check it per the Service Manual so you can at least know it is functional per the Cadillac specs, just to be safe.   

Good luck..!

[J. Gomez]

Having the same thing happen with my fresh rebuilt engine. Restored carb was on the car before the rebuild and did nothing to it. Timing has been set on the new engine and the idle is very low. The big air screw visible by the linkage doesn't make it idle up faster and I can't get more speed by adjusting the 2 front screws on the carb now either. Consequently, my generator light is dimly lit all the time as the car idles.
Should I change the timing to my ear and speed up the engine that way, readjusting the needle adjustments later? I'm at a loss as nothing on the carb changed but it sure runs differently and slow, almost to the point of killing. Any suggestions?
Thanks,
Chuck

Chuck,

Sorry my friend no help from my side as I will be doing the carb and timing adjustments one of these days, as soon as the kid leave me be with their “Dad can you fix these..!” 

Maybe someone can chime in and offer a few hints, I sure will keep tabs on this one in case I run into the same issue.   

Good luck..!

[cadman56]

Clay,
Put your old regulator on and see what happens.  If no better check generator.  If better, either adjust the VR or replace it.  I've never had to adjust a new one I ever installed.

Chuck,
Make sure the TV rod is fully pushed back and your throttle plates are CLOSED completey.  If they are open just the teensiest bit no adjust ment works.

Now if I can just find out what is wrong with mine.  Oh well, life is grand.

Good luck all of you.  Larry

[bcroe]

Generators don't do well at 550 rpm.  Raise it to a high idle before
checking the voltage.  Bruce Roe

[carguyblack]

Thanks Larry, you've given me hope. My transmission man is coming over tomorrow to adjust the TV rod etc. as the transmission was rebuilt by him just before the engine went through the machining. Hasn't been run until today and he didn't want me driving the car before he made sure it was all adjusted correctly. He said it was really important for him to do that. Maybe that rod is not adjusted right and the whole thing will smooth out after he makes the transmission adjustment. I had forgotten that the carb and the TV rod were interdependent Here's hoping!!
If the idle can go up, the generator light is sure to go out as well. I can tell by the smell of the exhaust that something is off and isn't a clean burn either. I'll post tomorrow with the results and hopefully I'll be a happier camper.
Chuck

[Lexi]

Guys, great suggestions. I may 1st try a generator isolation test (to take the VR out of the equation). Jose's suggestion makes sense as the factory setting for the new regulator may not agree with my Caddy's. Bruce is correct that generators don't put out much at idle, (when properly working) though I have tried to mix up run times with a lot of secondary highway speeds where the charging should have been sufficient to maintain the battery properly. Rev tests have been erratic. I believe once you are at fast idle speeds, say around 1700 rpm, you should get readings of at least 13 volts at the battery. Sometimes I do and sometimes I don't. Some of them around 12.5 or so. Not good in my opinion. Never thought of putting the old VR back on to see what happens. Sadly, we are near the end of our driving (and driveway auto repairs) season,  so don't know if this will be resolved before the snow flies.

Chuck regarding your idle issues. If TV rod/linkage adjustments do not help I have a question. Do you still have ignition points (or did you install electronic ignition)? I may have a gremlin in my distributor, (another post perhaps), but noted (obviously) how idle can alter with a change in dwell settings.  The shop manual if I recall says to adjust them by ear to engine speed then at the point of faltering back off 180 degrees (1/2 turn approx of the allen set screw). All the old time mechanics would tell me "GM, always 30 dwell", but the manual provides a spread with 30 being close to center, (26-33 or something like that). Seems those who wrote the manual opted for the ear test perhaps to take into consideration distributor wear. My car seems happiest around 28 1/2 degrees. Then as usual check your timing as it can change once you start adjusting dwell and for vacuum leaks. Hope points are clean and not pitted, or defective even if new (along with your condenser). So many '56 Caddy ills my brain is being tapped out!

Clay/Lexi

[carguyblack]

Thanks, Clay, for the suggestions. Yes, brand new points and timing and points set to the manual. When the TV adjustment is set, I'll play around with the timing and carb settings to ear if the running doesn't change. As I recall, I've always had to dance around a bit on these final adjustments. These cars of mine at least never seem to be a "plug and play" but rather a "hunt and peck".

[Lexi]

Chuck, well put. Mine have never been 'plug and play' either. "Hunt and peck", yes, that is more like it. Got to remember that one. Clay/Lexi

[James Landi]

 YOu truly DON"T know if your distributor's vacuum advance is working unless and until you personally "pull a vacuum" on the device. You have sufficient lung capacity to cause the "stator plate" to move slightly, by adding a piece of rubber hose to the device and sucking on it---with the cap off.  The vacuum advance in your car is VERY active and constantly adjusting the timing.   A leaking advance will cause your car to run rich and run rough, especially at idle.

[carguyblack]

I have a brand new vacuum advance in the distributor. The transmission TV rod was exactly where it should be so there was no adjustment or change effecting the throttle plates and the transmission works flawlessly. However, the idle, since I changed nothing, remains the same. I went through all the vacuum connections and rubber to make sure they were tight and sound and they all are. Generator light remains on as the idle is still very low and nonadjustable. I spoke to my carburetor doctor and he thinks I may have the wrong base gasket on the carb. Unfortunately, I trusted the mechanic who was building my engine to do it right and make sure he used the correct gasket. I'll have to take the carb off tonight and check that out. Before that, he told me to place my hand over the throat of the carb and see if it kills instantly, raises the idle or falters for awhile and then kills. It should instantly kill, so I hope it does that. If not, I'll be chasing some sort of vacuum leak. I noticed my vacuum driven dash pot on the throttle linkage at the firewall does not work but I unplugged it (lots of vacuum to that line) and plugged the line with no change to the idle. I've ordered a new one so it will be  correct but that doesn't solve the low,nonadjustable idle problem. I hate undoing the carb and linkage again but that's the only way to be sure. Stay tuned. I'm not driving away any time soon, it would appear.
Sorry if I barged in on this generator posting. My case is a side story to the original question, which I hope may be useful to someone once solved.

[Lexi]

Barging is OK Chuck. Kinda sounds like you have a vacuum leak somewhere. Clay/Lexi

[James Landi]

Alas, have to agree with Clay/Lexi --- your "dash pod" should entirely withdraw at idle, and is intended to extend and push the throttle to slightly rev the engine if the engine begins to lose power or begins a to develop a "rolling stall" as a consequence of an unusual power draw and/ or with temperature extremes.  You may well have the wrong gasket set for the intake to carburetor fit.

[Roger Zimmermann]

The '56 Sedan de Ville I had was equipped with a Carter carb. According to the shop manual, idle and RPM are adjusted only with the air screw and both mixture screws. When I bought that car in 1982, somebody had installed a screw to adjust the RPMs at idle. Without that screw, there was just...no idle. I adjusted the RPMs to have the generator light was just out.
Otherwise, the car ran well and had a rather good mileage, about 13 l/100km on long distances.

[carguyblack]

Roger,
Thanks for your input. Could you tell us where the additional screw was installed? Was it installed to contact the idle up cam?
After removing my carb yesterday and determining it had the correct gasket, I replaced the gasket nonetheless with another new one, Prior to that I blew air into all the ports, having removed all the set screws. Everything looked brand new as it did before I touched the engine to rebuild. Couldn't find anything amiss. Reassembled everything and started the car once again to a "no idle" situation. I can turn the large air screw all the way in or out and it doesn't change the idle at all. It makes more air sucking noise one way or the other but no effect on the engine running nor idle. Putting my hand over the top of the carb while running immediately kills the engine, so that test is ok.
The only way I can get the car to hold idle and run reasonably is to adjust the idle up cam screw to a proper idle speed. I'm certain that this is not proper and that the carb "rest" stance shouldn't be up against that cam all the time, but that's the only way this thing will run. Very disappointing to say the least.

[carguyblack]

Should have said, in the interest of the generator side of this post, that the generator light is off now that the car is idling where it should be! However, I'm sure the way I got it to that idle is incorrect. Something still is wrong but I'm at a loss. My carb doctor mentioned that I could send the carb back to him to check, but I really find it hard to believe that is the problem. Maybe just from sitting off the car for 6 months wrecked something but it sure doesn't appear to have.

[fishnjim]

1. 12.6-.7 is normal 12V charged battery voltage and therefore an operating VR will not cut in and charge.   Turns the lights on and other power draws and see if it kicks up to 13+-14.5 once it drops below ~12.
2. These "vacuum idle" carbs as I call them are tricky.   If the vacuum system isn't good/tight, they'll drive you crazy.   There's alot to leak check because of all the vacuum boosted accessories.  So it could be your brake booster, wipers, etc. that are the problem.    By good reason, they abandoned all that nonsense.
Check the procedure but what I recall is you adjust the two metering screws one at at a time until they run rough in either direction and set in between, then adjust the air, but maybe vice versa with several iterations. (It's been a while.  I changed carburetion, from original 4 bbl to 3x2.)   If it's totally out and won't run then, start by screwing in all the way and back out the metering 1 1/2 turns and the "air" according to the manual.(forgot # turns)   You can throttle up a bit if its not idling manually but it adjusted.  Timing is set first.
If the vacuum and carb are not good, then adding a "idle screw" on the fast idle cam like the later carbs is a good idea.   I ended up doing that with mine original carb before I rebuilt everything.

[Lexi]

Fishnjim thanks. Good to hear that the 12.6 - 12.7 volts is normal at idle. Did not think VR would cut in at that range. I am going to have the battery checked as it did not seem to have the reserve to properly turn the engine over after a drive. Battery is new. As for Chuck's carb/idle issue I believe your comments are correct with respect to setting up. Still sounds like a vacuum leak. Chuck does your car still have that engine vacuum pump thingy or was it removed during the rebuild? Lots of potential for a vacuum leak there as it powers your wipers and washer units (unless blocked off and changed over to electric). Clay/Lexi

[Roger Zimmermann]

Roger,
Thanks for your input. Could you tell us where the additional screw was installed? Was it installed to contact the idle up cam?

Yo are welcome! The screw is not at the idle up cam but at the location where a "normal" carb has it. On the attached picture, this is the screw on the left, with the spring. The carb is from my Brougham? both carbs were sent to Daytona. They removed the idle screw; when I installed the carbs back, I had no idle. Therefore, I added again a screw.