Using modern diagnostic tools with vintage cars

[rodneybeauchamp]

Interesting when you try to adapt new technology to older vehicles.

 

My faithful 20 year old Optilux timing light, dwell meter, tachometer and volt meter decided to fail some time ago (strobe light stopped working) l and I could no longer buy a replacement xenon globe. So I went and bought a nice professional timing light with digital readout and everything ( except it won’t make coffee) .Picture of the culprit below! Used it on a ‘63 Buick Riviera when it arrived and it worked fine. 😀😀😀😀

 

Well I decided to set the timing and dwell on my 1938 Buick Special, hooked it all up to a 12V supply and all I got was 45degrees of dwell regardless of what I adjusted the contacts to. Every reading, 45 degrees. 🤔🤔🤔🤔🤔

 

I hooked it up to my 1963 Buick Riviera and got a reading of 28 degrees which is close to factory setting of 30 degrees. So it’s working, but not on my ‘38.  I had a older style Engine Analyser similar to the photo below at I got at a recent swap for $5.00 and hooked that up and it showed proper readings as I adjusted the dwell (point gap). Got it set to 30 degrees and it starts easily. 😀😀😀😀😀

 

OK, so much for technology!
 

After much frustration, I discovered in the user guide (from another supplier) that the solid copper wire leads I use on the ‘38 give off too much EMF, UHF, ABC or some other frequency that makes the modern unit go to a fail safe mode. You need to substitute number one spark plug lead for a resistor type unit to read the dwell properly.

 

I think I’m going to rely on my $5.00 swapmeet unit for the ‘38 Buick as changing a plug wire on a ‘38 is not a two minute job.

 

A trap for young players and hope it helps others.

Rodney 😀😀😀😀😀😀

 

 

[Rusty_OToole]

A good man with a set of feeler gauges and a vacuum gauge can do as well if not better. I used to set points with a feeler gauge and double check with a dwell meter, never had to change a setting.

[PFitz]

12 minutes ago, Rusty_OToole said:

A good man with a set of feeler gauges and a vacuum gauge can do as well if not better. I used to set points with a feeler gauge and double check with a dwell meter, never had to change a setting.

This.

 

I haven't needed a dwell meter in 40 years.

 

Besides a volt/ohm meter, the only modern electronic tools I use is an Infrared hand-held "heat gun" for reading engine and brake temps, and an early 1970's vintage Sears Craftsman timing light.

 

The timing light is much more precise than turning the distributer head until the points open to get a trouble light to go out. And unlike many of the newer timing lights, it works equally well on 6 and 12 volt systems, with no problems around copper core wire ignition systems.  Plus, clipped on to each wire in turn, it can show dead or inductive crossfire spark plug wires.

 

However, the IR gun reading locks up if I get it within about three feet of solid core ignition wires. Only way to get it working again is crash it by removing the 9 volt battery.

 

Paul

[Bloo]

My attempts to use modern test gear on the 36 Pontiac have been 100% failure. In the case of the timing light(s), one modern wire was not enough to make them work. I have not tried a whole set.

 

When I first bought the car it ran lousy, and sounded to me like the timing was too advanced. When my Snap-On digital dial-back timing light refused to work, I just assumed it had died of old age (it hails from the 1980s). I didn't really have time to fix it so I went out and bought a new Bosch dial-back light. The Bosch didn't work either, though it did work on another car. Further tries with the Pontiac apparently killed the Bosch light. I figured out later that there is nothing wrong with the Snap-On light.

 

All this was done with a 12 volt battery sitting on the ground next to the car. An old Craftsman analog light with no dial-back feature worked fine. The distributor had to be put on a distributor machine to figure out the advance curve.

 

[DonMicheletti]

I'm in the same camp as Rusty.

I have seen a bad dwell meter drive a guy nuts. I have never had a bad feeler gage.

[JFranklin]

57 minutes ago, DonMicheletti said:

I'm in the same camp as Rusty.

I have seen a bad dwell meter drive a guy nuts. I have never had a bad feeler gage.

 

I once tried to do my taxes with a lying calculator. It's a good thing I caught it before sending everything off!

[Mark Shaw]

You might try to find one of these.  It runs on a 6V battery.

[JACK M]

So an old guy way back when says, "set those plugs with a dime".

I figured out after much frustration that two nickels wouldn't work.

[PFitz]

2 hours ago, JACK M said:

So an old guy way back when says, "set those plugs with a dime".

I figured out after much frustration that two nickels wouldn't work.

 

That doesn't make cents.    

 

I was taught to use a match book. Match for the thickness of the plug gap and the cover for the point gap. Then I quite smoking and had to buy a real feeler gauge.

 

Paul

Edited March 5, 2020 by PFitz (see edit history)

[Pfeil]

On 3/5/2020 at 1:44 PM, PFitz said:

 

That doesn't make cents.    

 

I was taught to use a match book. Match for the thickness of the plug gap and the cover for the point gap. Then I quite smoking and had to buy a real feeler gauge.

 

Paul

Actually the match stick ( sort of cardboard ) are used to pull through a new set of points to get the factory coating off of them so they won't burn the contacts on the first fire up.

BTW, try going to a auto parts store and finding some distributor points grease, and some carbon tetrachloride points cleaner. 

Edited March 7, 2020 by Pfeil (see edit history)

[Bloo]

I just use brake clean on a strip of printer paper to clean the points after they're in. The grease should come with the points. If it is not there, I use Redline CV-2, since I always have some around (its SO slippery). Anything would probably be fine. I think it may have been Vaseline back in the day.

 

Edited March 7, 2020 by Bloo (see edit history)

[Bloo]

On 3/5/2020 at 7:54 AM, Mark Shaw said:

You might try to find one of these.  It runs on a 6V battery.

 

Not bad. I like it. In the 80s I had a 6 volt Allen setup similar to your Sun, except the individual instruments pulled out of the rack and could be portable. I think it was from the 40s. I miss it. The Dwell/Tach was the best I have ever used.

[PFitz]

9 hours ago, Pfeil said:

Actually the match stick ( sort of cardboard ) are used to pull through a new set of points to get the factory coating off of them so they won't burn the contacts on the first fire up.

BTW, try going to a auto parts store and finding some distributor points grease, and some carbon tetrachloride points cleaner. 

 My electrical engineer brother taught me to use a new-ish dollar bill pulled through point contacts - ignition, generator cutout, or relays - to clean them.

 

For worn, or burned points, I have small ignition points files. He also taught me to never use any abrasive to clean contacts, except in roadside emergencies. If any tiny pieces of grit get stuck in the contact surfaces it will cause contact burning that much sooner. That advice has served me well for over 50 years.

 

And I use a slight smear of the same high-temp grease on the breaker point cam lobes as I use in the distributor grease cups.

 

Paul 

[Pfeil]

9 hours ago, Bloo said:

I just use brake clean on a strip of printer paper to clean the points after they're in. The grease should come with the points. If it is not there, I use Redline CV-2, since I always have some around (its SO slippery). Anything would probably be fine. I think it may have been Vaseline back in the day.

 

I still have two tubes of distributor cam grease which is way thicker than Vaseline. A warmed up engine would cause Vaseline to run. Some people today are using white lithium grease for points and that's still way too lightweight and will melt off the back of the rubbing block. 

[Vintageben]

Yeah I like using feeler gauges on my old Chevs and also this neat timing light. Got no idea of its age but still works well. 

[Bloo]

I have one of those too. Maybe not the same brand, but long enough ago they all looked like that. They are pretty dim. You might have to check in the dark, particularly if the marks are down in some little hole. Great for 6 volts!

[Vintageben]

57 minutes ago, Bloo said:

I have one of those too. Maybe not the same brand, but long enough ago they all looked like that. They are pretty dim. You might have to check in the dark, particularly if the marks are down in some little hole. Great for 6 volts!

Yeah most of the time I only get to work on my cars evenings or very early morning, this could explain a lot about my cars 😁🤣