48 Super engine problem

[Guest Blackpack]

I have been trying to narrow down a problem I have been having with my motor running badly and then not running. Twice!

The first time I had this problem was a couple of months ago. I went out to start the car and it would not start at all. It had run great just the day before. I first tried replacing the electric fuel pump and that made no change. Then I replaced the coil, cap, rotor. No change. Then I replaced the condenser and that did it! Car ran great for a couple of weeks and then I had the same problem. I changed the plugs. No change. Then I replaced the condenser again and it fired up and ran smoothly. I took the car out and got two miles down the road and the amp meter was going a little crazy and the the car started cutting out. I had to turn my lights on and they were real dim. Then they would get bright for a secon. All the time, the amp meter continued to go from normal to discharge and the motor kept going out and eventually quit. It started right back up and I limped home. The car fires up and runs smooth right now, but I'm afraid to drive it. My question is...does this sound like a symptom of a bad voltage regulator? If the voltage regulator is bad, could it be frying my condendors? Thanks!

Edited June 18, 2017 by Blackpack
Typos (see edit history)

[Pete Phillips]

Can we assume you are still running six volts?

Somewhere I read recently about someone who did a study of condensers and found that they had a 4 in 10 chance of getting a bad one, even though they were purchased new at a reputable parts store.  Yes, it sounds like you have either a bad regulator or bad condenser, or both. I don't think a bad regulator will fry the condenser, but a bad coil would do that, and also a bad set of points would do that. The condenser's job is to receive the momentary electric charge when the points open and the electricity has nowhere else to go. Check your points when they are open, for a proper gap.

Pete Phillips, BCA #7338

1948 Super sedanet (and other Buicks)

[Beemon]

What brand condenser do you buy? I have never had an issue with the NAPA Echlin brand. I've heard others having issue with the cheaper stuff, something about the ground coming loose in the can and causing a short. 

 

If you have a multimeter, you can check to see if the capacitor is within the mF range specified by your shop manual. To check for leak down, switch to voltage and if it's steady, it's good - if it leaks down, it's bad. 

[Beemon]

Also, do you have a ballast resistor? 

[Guest Blackpack]

Thank you for the responses. Pete and Beemon, yes I am still running a six volt system. The first condenser was from Bobs Automobilia and honestly, I didn't pay attention to the brand. I also bought a new coil from them at the same time. The condenser I just put on was from NAPA. I don't think there was a ballaster resister on a 48, so I would have to answer no to that.

[Beemon]

Check your primary and secondary coil resistance and see if it's within spec as well, you may be getting too much juice to the points and condenser.

[Guest Blackpack]

UPDATE: I think I may have found the problem. I noticed that my gas gauge was pegged on full, but every once in awhile it would start bouncing wildly from half to full. When it did this, the amp meter would go all the way over to discharge. I reached behind the dash and as I touched the wires, the gas gauge would go to half and stay there and the amp meter would go to the middle. After getting everything stabilized I took it for a 5 mile drive and it ran great! So now my question is, if I had a short, would that fry my condenser?

[Bhigdog]

1 hour ago, Blackpack said:

UPDATE: I think I may have found the problem. I noticed that my gas gauge was pegged on full, but every once in awhile it would start bouncing wildly from half to full. When it did this, the amp meter would go all the way over to discharge. I reached behind the dash and as I touched the wires, the gas gauge would go to half and stay there and the amp meter would go to the middle. After getting everything stabilized I took it for a 5 mile drive and it ran great! So now my question is, if I had a short, would that fry my condenser?

First thing you need to do is get a good fire extinguisher for the car and keep one battery cable wrung on the battery by hand so you can quickly disconnect it. I think the condensers are only a coincidence and you have an intermittent direct short to ground somewhere hence the dim lights and wild ammeter. You have not found the problem it's waiting to burn your car to the ground.....................Bob

Edited June 19, 2017 by Bhigdog (see edit history)

[Joseph P. Indusi]

Getting a good fire extinguisher is good advice.  Next I would get the shop manual and make few copies of the wiring diagram.  Then you need to fully investigate the condition of the wires behind the dash.  Use the wiring diagram to confirm the wire connections you find behind the dash.  Correct any and all problems you find.  Finally, buy a good quality cutoff switch for the negative battery terminal and cable and always shut off this switch when not using the car..

 

Joe, BCA 33493

[60FlatTop]

In Eastern Pa. you should be able to do a little hunting around and find a shop that still has a distributor machine and someone who knows how to use it. You can run your distributor through all the tests and come home with confidence in it.

 

The other thing to search out is an engine analyzer with an oscilloscope. I used to have a nice Allen machine that was phased out in the mid 1970's when electronic stuff came in. If you can't find a garage with one, most real geeks can still run one on your car. I could do both this afternoon if needed. Ummmm, I know some real geeks. Yeah, that's it. I know some.

 

There is a world of information you can glean with that kind of test equipment. It was common equipment in good shops when you car was new. The idea of "old cars" being simple and fixed with pliers, and screwdriver, and bailing wire is flawed. 

 

I have noticed that megaohm meters are becoming reasonably priced. If I was still servicing cars I would have one to check for leakage and grounds on the cloth wire cars. If you threw 500 volts on the rat nest you jiggled under the dash you'd find some work to do real fast. It might be worth it to get one and isolate some wires to chase down. Or catch a refrigeration guy who likes cars. They have them.

 

Well, everything I wrote says get test equipment. Cars were never as simple as people remember them.

 

Just curious, is that the car that had the shaking problem a year or so ago?

Bernie

[Guest Blackpack]

Hi Bernie, good to hear from you. Yes, it is the same car that was shaking. After three months, a new clutch and rear end and a complete new gear box, we discovered the problem. The mechanic that replaced the clutch just before I bought the car did not tighten the bell housing bolts and all the lower bolts fell out in transport, causing the bell housing to separate from the motor and putting the spline in a bind. Added two new bell housing bolts and it's been fine ever since

Edited June 20, 2017 by Blackpack (see edit history)

[Guest Blackpack]

Thanks Joe,

 

I inspected the wiring behind the dash last night and it all looks like it's in pretty good condition. It has the original cloth insulation, but I believe it has been replaced some time ago. There are little white numbered tags on each wire. I have not positively isolated the wire that is causing the problem. I do not see any wire that is bare. Someone has hooked up a toggle switch using a modern day wire with plastic insulation, but that wire does not seem to be the culprit. I just know that it doesn't take much bumping of the wires to make the fuel gauge peg out. Nothing seems to be sparking or getting hot though. I do have a fire extinguisher and a quick disconnect on the negative battery post though. The wiring under the hood looks pretty worn. Most of the cloth insulation on the wire leading from the firewall to the coil has come off leaving the secondary insulation exposed. I think I will replace that sooner than later

Edited June 20, 2017 by Blackpack (see edit history)

[60FlatTop]

I thought I recognized the car. I still smile and remember the comment I made about cracking walnuts with my smooth clutch. Now there are two. Have you tried it?

 

Your harness is covered with a braided loom, as I am sure you know. But your problem areas would be in the wires extending from the loom where heat and age affect them. Inside the loom I am sure they are brightly color coded and quite fresh looking. I have removed harnesses from four of my cars, made repairs and reassembled them. I would remove the dash bezels and covers to gain access and sit in the front seat with the harness in my lap to make repairs. And not dig under the braid unless I had a real good reason.

A few lengths of color coded modern wire with cloth covering would make a nice job. Practice a good lineman's splice and use shrink tubing to hide your work.

I wired up a removed Ford truck harness, repaired, and modified it to work with a Buick 350 engine swap. Everything looked and worked as original. Even started with the key and no added start button.

Here is my Riviera harness, not braided, on a little table I still use today.

That green tool is a life saver on modern cars. Your double grip terminals can be reused or sourced from a surplus electric warehouse. I still have a couple hundred in various sizes. I use rubber tubing from windshield squirters to replace the old rubber ends, That tubing is thinner.

If you do break into the braid shrink tube in a hidden place works great.

The only problems I can think of were getting the correct color. And that is mostly me. The '64 Riviera uses an apple green #16 wire for the temperature sensor, as I remember. Mine has a lineman's splice into a yellow wire painted green with Krylon. There is also a #14 purple wire that goes to the starter solenoid. I had to make a single order of a few feet from Rhode Island Wire Works.

Just start tagging and making notes. It is nice peaceful and clean work, kind of relaxing.

Well, most of it. There was that '58 Silver Cloud that had a fire inside and shorted the bundle all the way back to the battery in the trunk. Had to cut that one apart with an Exacto knife and catalog all of it.

Bernie