Looking for distributor tester, or engine scope

[JohnnyMaryjo]

I am in need of anyone in the Pa,/ Oh, / West .Vir. area that knows of a mechanic that has a engine scope ,and a distribor tester

for my 1941 Plymouth P-12

there is something either with the piston rings,or valves going wrong

please help

thank you

Johnny  / MaryJo

[Mark Shaw]

First I suggest you do a compression test and a leak-down test to determine if the rings & valves are sealing.

[JohnnyMaryjo]

thank you for the reply

we did do that and they were 105 110 

But someone told me that that is not 100% cause it could be causing the bottom of the motor like the springs etc ?

any truth ?

thank you

Johnny

[TerryB]

6 hours ago, Mark Shaw said:

First I suggest you do a compression test and a leak-down test to determine if the rings & valves are sealing.

I have been working remotely with Johnny on his problem.  His receipts show the engine was rebuilt about two years ago. New oversized pistons, rings, valves reground, new timing chain and gears, rebuilt carburetor, new original style coil. Fuel pump pressure tested, compression tested, vacuum gauge tested. Of course new points, cap, and rotor.  Receipts don’t show any new valve springs or mention camshaft regrinding.  Lots of easy stuff been checked in the last two weeks.  Something else going on that is not obvious with checks done so far.  Johnny says the engine breaks up at higher rpms.

[TerryB]

Also, Johnny is new at doing diagnostics but is learning quickly. He bought a new compression tester, vacuum gauge and picked up a used dwell/tach meter and a used Snap-on timing light. His compression numbers were good as he reports above, dwell is good (36 degrees), fuel pressure is 3.5 lbs with engine running and he said is vacuum test numbers were good.  The unknown is timing because the timing light is 12v.  
 

What he needs is an experienced shop or person to look at his car.  One thing he has said to me is his engine is making a noise and an old timer told him it sounds like a bad piston or rings.  Compression test numbers don’t seem show any problems.  Compression test was done dry.

 

So if you know a shop that can help him it would be greatly appreciated.

[edinmass]

It’s a very simple engine. Never heard anyone say a noise sounds like piston rings. Very few mechanics alive today can tell noises apart. Wrist pin, piston slap, rod noise, valve train rattle……….unless you have fifty years in a shop, most is just conjecture. Do a cylinder power balance test with a test light and rpm setting on a DVOM. It should help you pinpoint the suspect hole. In my humble opinion, if you have a noise in that engine……..just pull it out and tear it down. Don’t assume anything is square, or in specification. That platform is usually bullet proof. 

Edited October 26, 2022 by edinmass (see edit history)

[60FlatTop]

If a new condenser was installed it could be breaking up even though new. Test with a known good one if it is ignition breaking up.

 

Looking for an oscilloscope is a good idea. Properly used it will pin point a lot of problems. Keep watching for a phone app I don't think they are far away.

 

Since I became a Chrysler owner I have been doing a lot of reading at this site: https://p15-d24.com/

 Seems like a good one.

 

 

[Rusty_OToole]

Any old time auto electric shop should have a distributor tester if they haven't thrown it out. Let your fingers do the walking thru the yellow pages. Or call up some old garages especially in small town and rural areas where they don't renovate and modernize every few years.

[DFeeney]

I use a 12 vt timing light on my 6 volts cars.  Set the 12 vt. battery on the floor and hook up the light to it. Then put the trigger wire on the spark plug wire one at a time.

[Littlestown Mike]

"Breaking up at higher rpm"?  sure sounds like ignition to me--at least that is what i would be checking first. 

Never assume that old electrical components are good just because they just came out of the box--especially condensers.

Any evidence of carbon tracks inside the distributor cap?

[edinmass]

Am I missing something here? It went from a mechanical engine noise to a running problem? Doesn’t get more basic than this engine. Any running problem should be a simple diagnosis. You don’t need a scope or a distributor machine to figure it out. How about a complete and clear explanation of what you are trying to fix. Running a correct diagnostic procedure should identify the issue in just a few minutes. 

Edited October 27, 2022 by edinmass (see edit history)

[Bloo]

One more thing to look at:

 

See this set of points? Yes I know it probably isn't the right one for your car but look at the spring. It's that flat silver colored thing over at the right of the picture.

 

The spring is made of spring steel, and can be silver or black/blue steel. Now look at this set:

 

 

See the copper strip? That used to be a thing on premium sets of points. Note that the steel spring is underneath it.

 

Now look at this set. Mainly you see copper, but if you look really close you can see the spring underneath the copper strip:

You can have the spring without the copper strip (like in the first set of points), but you can't have the copper without the spring. On some points for some cars, the spring was a separate piece you had to hook in place yourself. Look at this:

 

 

There have been a couple instances here in the forum over the last year or two where someone was sold a set of points and the spring was missing, and they didn't realize it, so they just put them in with the copper alone. The copper by itself won't do the job. It isn't springy enough. The engine will miss horribly when you rev it up.

 

I'm not saying that is what's wrong, but it couldn't hurt to take a quick look. You can have steel without copper, but you can't have copper without steel.

 

[TerryB]

11 hours ago, edinmass said:

Am I missing something here? It went from a mechanical engine noise to a running problem? Doesn’t get more basic than this engine. Any running problem should be a simple diagnosis. You don’t need a scope or a distributor machine to figure it out. How about a complete and clear explanation of what you are trying to fix. Running a correct diagnostic procedure should identify the issue in just a few minutes. 

this is all information that is coming without being there in person.

The problem, as reported by the owner, is that it the car runs bad at high rpms, when the gas pedal is near full throttle.  It seems to be running good at lower speed.  Push down on the gas and then problems kick in.

 

To that add the owner says the engine also makes a noise that can be heard when it’s idling.  The noise, in his words, sounds like the slap of a straight razor on a barber’s leather strap.  The noise does quiet down some as the engine warms up from what he says. It’s this noise that was diagnosed as a possible broken ring or piston by someone the car owner met at a car show.

 

So the issues are the car apparently runs poorly as the rpms climb and the engine is making a noise that may or may not be related to the poor operation.  Diagnostic tests done so far by the owner have not shown any standout problem.  The distributor check was recommended by me as I would want to know if the vacuum advance, mechanical advance and the points are all working as they should.  

 

The owner has also had the carburetor rebuilt and this week he installed a NOS ignition coil.  A picture of the distributor he sent me seems to show the points are the kind with both a contact and tension spring and they appear to be in decent shape.  Condenser has been changed too.  

 

My leaning is to something electrical and the engine noise I think might be valve adjustment.  There is about 350 miles between Johnny and me so getting there in person to look and listen is not possible.  He sure could use someone local to check out the car for him.  He is in the Pittsburgh area.

Edited October 27, 2022 by TerryB (see edit history)

[TerryB]

11 hours ago, Bloo said:

One more thing to look at:

 

See this set of points? Yes I know it probably isn't the right one for your car but look at the spring. It's that flat silver colored thing over at the right of the picture.

 

The spring is made of spring steel, and can be silver or black/blue steel. Now look at this set:

 

 

See the copper strip? That used to be a thing on premium sets of points. Note that the steel spring is underneath it.

 

Now look at this set. Mainly you see copper, but if you look really close you can see the spring underneath the copper strip:

You can have the spring without the copper strip (like in the first set of points), but you can't have the copper without the spring. On some points for some cars, the spring was a separate piece you had to hook in place yourself. Look at this:

 

 

There have been a couple instances here in the forum over the last year or two where someone was sold a set of points and the spring was missing, and they didn't realize it, so they just put them in with the copper alone. The copper by itself won't do the job. It isn't springy enough. The engine will miss horribly when you rev it up.

 

I'm not saying that is what's wrong, but it couldn't hurt to take a quick look. You can have steel without copper, but you can't have copper without steel.

 

Points like the Standard set are in their now.  The new set he has but not installed are the kind where spring and electrical contact are one piece of metal.

[60FlatTop]

13 hours ago, edinmass said:

Any running problem should be a simple diagnosis.

"The complexity of the diagnosis is directly proportional to the distance from the car and the seating position of the diagnostician."

 

I prefer being seated at my desk. I would never attempt it from my couch with a laptop.

[edinmass]

The update was helpful. So engine noise and running problems. One step at a time. Figure out the noise, and if it needs to be addressed. Then chase the running issue. People new to the hobby need helping hands, and always happy to try and help. He is in good hands with others in the background, so shall stand mute till they need more help.

Edited October 27, 2022 by edinmass (see edit history)

[JohnnyMaryjo]

the person who caN FIX ANYTIHNG PREWAR

WHERE ARE YOU LOCATED

DO YOU HAVE DIST. TESTER OR A OSCILLOSCOPE

THIS IS WHAT THE NEXT STEP SHOULD BE

[F&J]

Like Ed said, a prewar mechanic does not "need" the scope or dist tester to diagnose that car.  Those tools can be used to fine tune things later, but are not ''absolutely needed'' to find the main issue.

 

What do you think was used back in the days before those things were invented.  Hint....common sense and experience with those early engines.  They are so simple compared to todays engines

 

and don't assume any type of parts are OK because you bought rebuilt or new parts.    I will bore the heck out of some people, but a local guy had a 40s Ply woodie that he never would let me service.  He let me fix all his others.  Since purchased, their Ply never ran good enough to take more than a few miles.  It "fell on it's face" whenever you tried to just cruise steady on a 45mph road. He said it felt fuel starved or wrong timing, because stepping more on the gas pedal lightly, made it slow down.

 

The guy ships the car to to a old timer expert in the next State, and that guy replaced so many parts but after having the car flatbed delivered back home, same exact problem. I've never seen so many random fresh white paint marks near the timing marks LOL.  Geezus, you should test the timing by ear when chasing an odd issue.

 

So he spent over 500 in towing both ways, a grand or two for "repairs"  ummm "guesses" is more like it...

 

So out of desperation he finally calls me.  I said pull the choke out just a little it when it falls flat and let me know if that works.  Well, he brings it to my place and said he forgot to try the choke test.  As soon as his wife took him home with her modern car, I did the choke test and that motor came alive.  The owner bought a "nors rebuilt carb'' from N B Pease.  So he and the old timer wizard assumed it was good, even after taking it apart to check for dirt.  

 

I knew it felt like wrong main jet size, so I looked on the web and read where 1940s Ply Sales Brochures offered a economy "fuel miser carb" with super small jet size for flat, low altitude-land out in the midwest.  So call me a tractor mechanic but i used the various sizes of Torch Cleaning Bits to ream the jet a bit at a time.  First try was 90%  better, 2nd try was 100% mint.

 

He comes back with wife and his modern car to pick it up, and I could tell he does not believe me when I said "it's fixed, it drives so perfectly that i wish i could keep it".  He leaves for the 45 minute trip home.  I get a call in 20 minutes,  Oh crap I wondered...did it quit running?  No, he called so say it was finally so perfect for the first time ever, that he had just stopped to let his wife drive it the rest of the way home for her to see how good it ran. (it is her car)

 

 

[edinmass]

N.B. Pease.....I literally grew up in that place. He is closed now, and selling off everything. It's just about gone.

 

 

[TerryB]

Actually the owner tried a larger main jet just in the past day or two that he got from his carburetor guy, it was a #270 if I remember correctly.  He said it ran worse with the larger jet. If my old broken body wasn’t so broken and not working I’d drive out there myself and see and listen.  I’m lucky if I go more than 10 miles from home these days.

 

Picture Johnny sent me shows #270 main.

 

[F&J]

16 minutes ago, TerryB said:

Actually the owner tried a larger main jet

I was hoping nobody thought that I was saying that car needed a bigger jet. 

 

I was just pointing out that you can't always assume a new or NORS part is always good.

 

32 minutes ago, edinmass said:

N.B. Pease.....I literally grew up in that place. He is closed now, and selling off everything. It's just about gone.

 

 

That's really sad news but we all knew that age made it tough for him to climb all the stairs getting parts for the few customers that still went there. The internet really eliminated his customer base after the older customers passed away.  Saturdays always once had a long line of people waiting for parts there, many drove from out of State too, like me.

 

I sure hope all the hundreds of parts books get saved and not stored in a box to be forgotten.  He had every parts catalog for every part maker and brand name ever made, and measurements of crazy stuff like king pins and bushings, so he could "make up" a king pin set for any obscure car by looking up the sizes, Lengths/OD/ID to get your car going again.  He has an ancient wheel book listing wire wheels, steel disc, etc with sizes and bolt patterns, amazing to see those books

 

 

[TerryB]

Understand your story about the Plymouth but it does highlight that many things have been thought of and tried.  So at least now with the jet change it may not be lack of fuel.  I want to continue to point out Johnny is new to the world of automobile diagnostics and is doing his best to test and respond to things to try.  Things that sound simple and the understanding of how its all related takes time to learn and he is at the very beginning of that learning curve.  So once again, if you are close by and can help send Johnny a PM or if you know a shop in his area post it here or contact him directly via personal message.

[JohnnyMaryjo]

Terry

you are the BEST

thank you

Johnny

[carbking]

Chrysler did not specify diameter on the main jets used in the BBR series carburetors.

 

ASSUMING that Johnny has the original D6A1, the original jet was part number 159-61s. This jet was calibrated to flow 254~258 cc's/minute. Again, no diameter was specified.

 

The 159 prefix is the prefix for this style jet. Carter did NOT make this series jet with a number as high as 270. Is the 270 jet aftermarket? Or is it a Chrysler jet marked with the flow rate, rather than the part number? What is the diameter?

 

I did measure a 159-61s jet, and it measures 0.054 inch. The part numbers on these jets are just that, part numbers. There is no correlation of part number to size. The next higher part number could be larger or smaller; it was just the next size needed for a different carburetor. 

 

And while testing of various items would be helpful; a more complete description of the issue at hand would be helpful to make a guess.

 

We know it is breaking up at higher RPM's.

 

So:

 

What RPM is considered higher?

Is the breakup in neutral at the shop? or driving?

If driving, is the "magic" RPM the same in first gear as it is in second gear?

Is the RPM at least close to the same if the engine is cold as when the engine is hot?

 

I really would suggest at this time not worrying about the break-up; and determine the cause of the noise, and fix that before it gets worse. Once the noise is gone, then the RPM break-up, if still present, could be addressed. 

 

Jon

[hidden_hunter]

3 hours ago, F&J said:

Like Ed said, a prewar mechanic does not "need" the scope or dist tester to diagnose that car.  Those tools can be used to fine tune things later, but are not ''absolutely needed'' to find the main issue.

I have a selection of period mechanic books for that exact reason, a lot of times there are simple tests etc that can be done that time has forgotten (mostly because they’re not suitable for more modern engines)

[mrspeedyt]

On 10/26/2022 at 2:58 PM, TerryB said:

Also, Johnny is new at doing diagnostics but is learning quickly. He bought a new compression tester, vacuum gauge and picked up a used dwell/tach meter and a used Snap-on timing light.

 

The unknown is timing because the timing light is 12v.  
 

Edited October 27, 2022 by mrspeedyt
did not intend for the photograph text to be so BIG. (see edit history)

[JohnnyMaryjo]

tRPM is considered higher?

Is the breakup in neutral at the shop? or driving?                                             in neutral 

If driving, is the "magic" RPM the same in first gear as it is in second gear?  YES 

Is the RPM at least close to the same if the engine is cold as when the engine is hot?   YES

 

[JohnnyMaryjo]

The higher the throttle  at 3500 4000 RPM starts to break up

even just running it in neutral

[edinmass]

8 hours ago, JohnnyMaryjo said:

the person who caN FIX ANYTIHNG PREWAR

WHERE ARE YOU LOCATED

DO YOU HAVE DIST. TESTER OR A OSCILLOSCOPE

THIS IS WHAT THE NEXT STEP SHOULD BE

 

Yes, I have a Sun Distributor machine, and a oscilloscope. And a bunch of other early test equipment. On a 41 Plymouth, I wouldn’t be likely to use any of it. The Plymouth six was a nice little package. Simple, robust, and reliable. Most of my diagnostic tools are home made. Without trying to be insulting, I would expect to figure out your problem in less than a half hour. Part of the trick to figuring out what is happening are small special purposes built tools……like a fuel pressure guage that can be taped to the front windshield to watch fuel pressure going down the road. Also a remote enrichment device to add fuel while driving at speed and under load independent of the carburetor. I would also heat and load test the coil. It’s unlikely to have a distributor problem…….unless someone assembled it incorrectly. I’m guessing that the “it breaks up under zero load” at 3500-4000 rpm isn’t exactly accurate as 3000 rpm is probably the end of the world for that engine. (Just checked, 3800 is max according to the factory. Seems high to me.) Countless things could be wrong, often times it’s two or three different problems sending you off in the wrong direction. There is no substitute for having 5000 or 6000 working hours in a shop. It’s experience that fixes cars…….after a few thousand running problems it gets fairly easy to fix them. I recommend going back to the basics. Compression, timing, spark plug gap, ect. Everything MUST be perfect before you go in to the next diagnostic step. Good enough simply isn’t. Here is a coil tester from the 40’s, and a Sun machine. The dirty distributor was just on it for disassembly…….not testing.
 

 

 

 

 

 

Edited October 28, 2022 by edinmass (see edit history)

[Littlestown Mike]

let me suggest something REALLY basic for our new friend.... Go out at night--really dark night, open the hood and watch while the engine is running at various RPM.  You want to see nothing.  However, you might see an electrical fireworks show.

Try spraying a little carb cleaner around the carb and intake with the engine running at the rpm where it starts to break down.  If the carb cleaner makes a difference, look for a broken gasket or something else in the area.

 

[edinmass]

Again, guessing isn’t the way to go. Diagnose and eliminate. Lean burn misfire, vacuum leaks, internal coil short, the list is endless……….sort the systems one at a time. You will figure it out.

[edinmass]

Coil tester from the 40’s on a 1929 Rolls Royce factory coil set up.

 

 

 

[SC38dls]

This is an unsolicited endorsement for Ed’s ability to diagnose a problem via the internet and fix the problem within 15 minutes not his 30 minute claim. I had a similar problem with my 38 Studebaker flat six except mine  would lose power as soon as I gave it gas. It would start and idle fine but would bog down with gas. He had me do the compression test, regap the plugs, reset the points, this after I had done a carb rebuild, new plug wires, new coil, new electric fuel pump, distributor cap, points & plugs. He said he was sure it was my distributor. He had me send it along with the coil to him. He texted me when it arrived and 15 minutes later texted it was fixed and he was packing it up to send back to me. It was a wire shorting out. He & Phil then celebrated with the bottle of Woodford Reserve I sent along with the distributor. 
The man is not bragging when he says he is good and can do amazing things with his knowledge. Follow his suggestions and you will be back on the road faster and with less expense than any other way of solving the problem. I still feel a bottle was not enough payment for him sharing that knowledge and willingness to help someone he had never met. He is just a great easy going good guy that wants to help and keep cars on the road. I just hope I can show him that appreciation in person some day soon. 
dave s 

Edited October 29, 2022 by SC38dls (see edit history)

[Rusty_OToole]

There you go - all you need is a special tool shaped like Edinmass

[edinmass]

2 hours ago, Rusty_OToole said:

There you go - all you need is a special tool shaped like Edinmass

A big,fat,old tool! With a big head. 😉

[60FlatTop]

I was out in the garage yesterday and looked down to see my rechargeable LED light in my hand. For a moment I wondered if I should pick up some D-cells for the old flashlight and be like a real mechanic.

 

Then in relief I realized I wasn't using the Android phone flashlight like one of those young people would.

[halifaxhops]

On 10/26/2022 at 9:59 AM, JohnnyMaryjo said:

I am in need of anyone in the Pa,/ Oh, / West .Vir. area that knows of a mechanic that has a engine scope ,and a distribor tester

for my 1941 Plymouth P-12

there is something either with the piston rings,or valves going wrong

please help

thank you

Johnny  / MaryJo

I have both that I know how to use.  In Halifax, PA N of Harrisburg.

[TerryB]

Got some new information yesterday from Johnny.  The used Snap on timing light he purchased might be wonky.  It has the advance knob on the back end and Johnny says with that knob at 0 he can’t see any factory timing marks on the front pulley but if he turns the knob to about 26 degrees advance then he can see the factory marks and the fixed arrow points to TDC mark.  Test was done with engine at idle and vacuum advance disconnected.  The TDC pulley marks were verified by doing the TDC check using the hole over cylinder #6.

 

The 26 degrees advance seems way off since the car starts easy and runs good at lower rpms.

[halifaxhops]

On 10/27/2022 at 1:23 PM, JohnnyMaryjo said:

the person who caN FIX ANYTIHNG PREWAR

WHERE ARE YOU LOCATED

DO YOU HAVE DIST. TESTER OR A OSCILLOSCOPE

THIS IS WHAT THE NEXT STEP SHOULD BE

I have both and plenty of them up in Halifax, PA

[halifaxhops]

On 10/31/2022 at 11:44 AM, TerryB said:

Got some new information yesterday from Johnny.  The used Snap on timing light he purchased might be wonky.  It has the advance knob on the back end and Johnny says with that knob at 0 he can’t see any factory timing marks on the front pulley but if he turns the knob to about 26 degrees advance then he can see the factory marks and the fixed arrow points to TDC mark.  Test was done with engine at idle and vacuum advance disconnected.  The TDC pulley marks were verified by doing the TDC check using the hole over cylinder #6.

 

The 26 degrees advance seems way off since the car starts easy and runs good at lower rpms.

Dial backs are notorious for being way off, digital ones are fine.