'59 Plymouth Forum

Hello all, I know most of you on here have V-8's in your 59's, but i was wondering if any could help with a rather annoying problem that ive had basically since ive owned my Plymouth, mine is a flat head 6, and it starts well, idles very smooth and runs well, the problem is when i take it on the highway, around 60 miles an hour, it will start to ping and the temp gauge will climb, i do run high test gas in it, a couple of years ago i replaced the points and condenser and that helped some, but so far this year its been really bad, pinged worse than ever, someone told me that my distributor shaft may be warped, or my vacuum advance is not advancing, any thoughts would be appreciated!

Bob

Since you are running Premium fuel, it probably isnt low octane!
Vacuum advances do fail, distributor shaft bushings get loose, spark plugs can get carbon buildup and become "hot", a build-up of carbon deposits in the combustion chambers could be the problem.
Interesting reading in the 59 Service Manual..
" To test for pre-ignition, take the car out and get it up to speed where the pinging begins, then turn off the ignition. If the engine continues to fire, it is pre-ignition, if it stops firing, it is detonation. Remove the foot from accelerator before turning on the ignition again." Try colder spark plugs to solve pre-ignition. Standard issue for the Six-cyl was AR-51
To cure detonation, check timing for correct setting. Start with 2.5 Degrees BTC. They suggest you retard the timing one degree at a time until the pinging is gone. If this fails, move on to distributor...if the bushings are loose you can actually wiggle the shaft. (Did you know the distributor needs oiling every 1000 miles?)
The distributor has an internal mechanical advance, and an external vacuum advance. Testing the mech advance requires a distributor Tester machine. Testing the vacuum advance accurately requires a vacuum pump (to see if the diaphram will hold a vacuum)..There are more directions than I care to type right now......
I don't know the tricks for removing carbon deposits from the combustion chambers without taking off the heads. Seems I heard you can have the car running, then slowly pour a bit of water down the carb throat, not fast enough to stall the engine. Sounds like a bad idea, but I believe I've done it in the past.
-roger-

Hi Bob,

I believe you are on the right track, it sure sounds like a timing issue. The vacuum advance is definitely a suspect. If it checks out OK, then set your disributor to the specified timing and mark the cap to the distributor housing in some way, maybe with a couple pieces of masking tape. Then drive around with the wrench in your pocket. If it pings, stop and move the cap a tiny bit one way and mark it to keep track of where you are. Drive again and If the pinging gets worse, take the cap the other way. This is the trial and error method that usually works. With timing set at the best average to work at all speeds without pinging, I would even consider burning regular gas.

Good luck
Tom

I replaced the distributor in my 318 a couple years ago. It had a loose bushing on shaft and thus the engine would miss. I initially tried to find a shop to just install a new bushing, with no success. (couldn't find a bushing) Ended up buying a new/rebuilt? distributor from Car Quest. New points came with dist.

I remember driving to a car show right after installing new dist. Drove about 20 miles and car stalled at a stop sign. Had to reset gap in points. Drove another 30 miles and got to car show and car was running terrible. New points burned up. Had a spare set of points in trunk. Installed these points in new distributor and car ran well. Don't know what was up with points that came with dist. They were lubed and set correctly when new distributor was installed.

Points? What are points?

Yeah, me being the "as from the factory" guy- Igave in a few years ago and went with Electronic ignition. I told the installer to make it unobtrusive, but he attached it to the inner fender in plain view (wires weren't any longer to hide it) so I sprayed it black and have forgotten about it.
If I recall, I did have the distributor rebuilt, which probably explains why I have a spare distributor on the shelf in the garage.

Thanks for all the replies so far on this issue guys, i have dried the drizzling water thing down the carb, nothing came out the tailpipe and no improvement was noted,i have been told by guys i know around here that it likely is a problem with my distributor, i am thinking of trying petronix to see if that solves the problem, im still thinking that it could be a vacuum advance problem because the car starts fine, runs smooth as silk until it reaches 55-60 miles an hour, then the pinging begins

Bob

If it was an 8-cyl, perhps you could borrrow a friend's distributor and see if it fixes things. Maybe look into purchasing a NOS 6-cyl distributor at Napa or other...?
Have you tried Tom Fox's trial and error method?

rogerh wrote:If it was an 8-cyl, perhps you could borrrow a friend's distributor and see if it fixes things. Maybe look into purchasing a NOS 6-cyl distributor at Napa or other...?
Have you tried Tom Fox's trial and error method?

Yeah, i have tried Tom Fox's trial and error method, but to no avail unfortunately, ill let you all know how it works out, ill go over to NAPA and see if they cant get me a new distributor for it

Bob

Try disconnecting the vacuum advance line from the distributor pot, plug the line. test drive if the problem continues it could be a carbon problem. If the problem ceases you have a distributor or timing problem. An engine that is consuming a large amount of oil will also have a pinging problem. Let us know what you find.

RICKYMOPAR wrote:Try disconnecting the vacuum advance line from the distributor pot, plug the line. test drive if the problem continues it could be a carbon problem. If the problem ceases you have a distributor or timing problem. An engine that is consuming a large amount of oil will also have a pinging problem. Let us know what you find.

Well Ricky, that was the answer, as soon as i did that the pinging stopped, and i actually drove it over 70 miles an hour without a ping, so it looks that i need a distributor, now the search will be on to find one, any thoughts on that will be greatly appreciated!

Bob

Wait for Ricky's reply, but I think you have a little more diagnosing to do.

You may not need a new distributor (or a rebuild). You may only need a vacuum advance unit. Or you may simply have leaks in your vacuum line.
While cruising at 60 mph, your car is not generating much vacuum. Vacuum increases when you stomp on the gas pedal, at any speed.
If you are getting pinging while CRUISING at 60, then I'd wager you need a rebuild on the distributor bushings or internal advance unit. The internal advance mechanism involves springs and weights, and requires the talents of a distributor rebuild shop.
If you get pinging when you ACCELERATE from 60, or are climbing a hill at 60 mph, then the vacuum advance is suspect.
Napa should be able to determine if your distributor is available new or rebuilt.
They can also sell you a vacuum advance unit to replace yours.

rogerh wrote: If you get pinging when you ACCELERATE from 60, or are climbing a hill at 60 mph, then the vacuum advance is suspect.
Napa should be able to determine if your distributor is available new or rebuilt.
They can also sell you a vacuum advance unit to replace yours.

Thats when it started to ping, accelerating from about 55 or so or climbing a hill, if i let my foot off the gas, it would stop.

Let's wait to hear from RickyMopar, but I think you need new hoses or a new vacuum can.
A 50-yr old distributor (mileage on odometer?) may also need a rebuild, but I would start affordably with a new vacuum can.

OK, Without being able to see how you have everything set up, a diagnosis would be lucky at best. I have not worked on a Plymouth L head for many years. I do have an antique Allen distributor machine that I still use regularly. Check your base timing with the vacuum advance disconnected. also the vacuum advance line is connected to the base of your carburetor. The advance mechanism uses ported vacuum to regulate the advance, the advance is added at part throttle-during easy cruise to help with fuel economy and better and more complete burn in the combustion chamber. Wide open throttle should have no vacuum advance. You can check the distributor for wear just by feeling how tight and smooth everything should feel. Note; the vacuum advance should not be hooked to the intake manifold vacuum port. Good tools to have, dwell meter, advance adjustable timing light.[/b]