rough running 49 new yorker straight 8ires right up.

[Tusler 49 New Yorker]

Hi,

This thing is driving me crazy. The eng hesitates badly every time you give it gas from a stop.

The eng has low compression across all the cylinders most of them are between 70 and 75 with #6 at 100.

I replaced the plugs, wires, cap, rotor. Cleaned the points, and that made the car start really great. Before it was turning over a few times before it would catch. i can stand outside reach in and turn the key and it fires right up. But the hesitation and a slight miss was there so I pulled the carb took it apart, cleaned it in a ultrasonic cleaner. I put it back together with a new accelerator pump. I took care to use some rtv on the gasket when I reinstalled the carb so I would not have any vacumn leaks where the carb bolts to the manifold.

It is stumbling and even stalling now.

I am open to advice...thanks

[Don Coatney]

Did you soak the new accelerator pump leather in oil prior to install?

[greg g]

double check for air leaks down stream from the throttle plate, intake to block. Where is your timing set?

[Tusler 49 New Yorker]

I did not soak the accelerator pump in oil, I did coat it with oil before I put it in.

Its not too late, should it be soaked in oil and for how long ?

Timing I had to set statically using a meter because I have not found a timing light for a 6volt system yet.

Edited April 5, 2014 by Tusler 49 New Yorker

[Don Coatney]

Soak for a couple hours. You can use a 12 volt timing light. Simply connect the power leads to any 12 volt battery and the spark plug lead to the #1 plug wire.

[Don Coatney]

rough running 49 new yorker straight 8ires right up

 

Do you have a 6 or 8 cylinder engine???? I do not understand 8ires??

[Dodgeb4ya]

Your N-Yorker eight uses the simple Ball and Ball 1BBL carb same as on a plymouth except for the anti-stall and kick down options

 

Do you have the factory 1949-50 Chrysler shop manual?

 

If so did you carefully read the caruretor section on how the different systems of the Ball and Ball carburetor operate and what each sub system does?

 

I think you stll have a accelerator pump circuit or step up piston circuit problem..With the engine off have yo looked down the carb while operating the throttle lever back and forth... you should see a very strong stream of gas sqirting each time you open the throttle. The stream should start squirting the second you start to open the throttle.

 

Did you install the small round gasket under the step up piston?

 

Bob

Edited April 5, 2014 by Dodgeb4ya

[_shel_ny]

rough running 49 new yorker straight 8ires right up

 

Do you have a 6 or 8 cylinder engine???? I do not understand 8ires??

 

OP has a straight 8 that fires right up

[soth122003]

If the stall and roughness is on initial accelerator action, i.e. stepping on the gas from idle to accelleration, make sure your check ball is installed under the accelerator pump piston assembly. Mine was missing and that caused a drag on the engine until the vacuum could pull enough gas from the float bowl.

[Dodgeb4ya]

^^^^^^^^^^^ Yep

[Lumpy]

Probably a carb/accelerator pump issue, but bad timing will "enhance" a bog, if you will. !! You can set your timing by just getting a fairly fast idle, just play with it, then road test it, if it pings, just turn it back a little at a time until it does not ping, then throw in a couple more degrees for good measure. Well....works for me anyhow. Having only set your static timing, it is probably quite retarded.

 

Doesn't one usually soak the plunger in gas? I always have. In this case it will soak in the carb, unless the check ball isn't there. But yes, it will swell up a bit better if you soak it when it's out of the carb.

 

Also, those carbs usually have a "summer" and "winter" setting for the pump-shot. Usually three settings I believe. Do you have it on the one that gives the strongest shot?

 

Sure wish I had a straight eight, I think they are too kool. With such a long intake manifold, I wonder if the eight is more prone to bog and stall, the mixture has to go a long way until it hits the cylinders on the ends of the motor. I'm thinking that dual carbs would be especially useful on the Eight.

 

Good luck.

 

ken.

[Dodgeb4ya]

I have some straight 8 chryslers-a 1946, a 48 and three 1950's .

 

They do not bog or die and have no tendency to do so.

 

They love to drink gallons of gas ,smooth enough when running right to balance a nickel on the head while idleing and like 60-80 MPH on the open roads!

 

Compression should run at least 100lbs, timing at TDC with a point gap at .016-.018".

 

Nothing complicated about these 323ci flatheads.

 

[Tusler 49 New Yorker]

rough running 49 new yorker straight 8ires right up

 

Do you have a 6 or 8 cylinder engine???? I do not understand 8ires??

Sorry about that it was suppose to say straight 8. the fires right up was in the text and somehow got up there.

[Tusler 49 New Yorker]

Thank you all for the suggestions. I took the Distributor out and cleaned it, reset the points.

When i retimed it, I found I had it way too retarded. I advanced it till it pings just a little going up hill since I am running 87 octane. I will put a little octane boost in the next tank maybe after I research it.

The accelerator pump is working great, if I step on it I get a bunch of torque to handle all at once.

The timing completely fixed the stalling and the hesitation. I put a vacum guage on it and the guage is rock solid, I also tried spraying WD40 around and got no changes in rpm.

I found an old timing light and plugged it in just to see what it would do, it does work, the light is not real bright but it does work. I am going to pick up a 12 volt batt and do what was suggested. (soo simple)

Before I was getting 10 mpg, I took it out for a drive today and only used 1/4 tank to go 100 miles so this made a hugh difference in the mileage.

I will get to work on the trans componets that tell the gears to drop down when I come up to a stop sign for my next project. I got all the youtube videos and manuals on the trans so it sould not be too difficult.

Probably replace the wiring and clean the govenor points very carefully. It shifts down now...I just have to put the clutch in for a few seconds to cause it.

Thanks again for all your help you guys are GREAT!

Edited April 6, 2014 by Tusler 49 New Yorker

[Niel Hoback]

    I have an old Craftsman 12 volt timing light and it works very well on 6 volts. Just remember to connect the wires for positive ground..

[desoto1939]

same here, also have a Sears Craftsman 12 volt timeing light. The light might be a little duller but this works on my 39 desoto and I just connect the wires or leads for the correct positive ground to get it to work. Basically opposite the setup as a 12v. So now the positive lead now go to the ground and the negative to the side that is getting the juice or electical.

 

I put the spark plug connecter on my number 6 plug wire.

 

Rich HArtung

desoto1939@aol.com

[Don Coatney]

For a brighter light connect the spark plug lead to the coil wire, not a spark plug wire. Try it, it works.

[Merle Coggins]

Rich,

Why do you use #6 plug wire? It doesn't make any difference if you use #1 or #6, but I'm curious why. (This is only true on a 6 cyl. I don't know which cylinder pairs with #1 on a straight 8)

Dons coil wire idea would work too.

Edited April 7, 2014 by Merle Coggins

[Tusler 49 New Yorker]

For a brighter light connect the spark plug lead to the coil wire, not a spark plug wire. Try it, it works.

Thanks, you are right, it works great. i sure like simple fixes that work. I am using an old set with a eng analyzer, vac guage, timing light, ... I just never got rid of it, I am glad I did not now I have a use for the stuff.

My wife thinks I am crazy but it sure is fun working on the old car, it brings back a lot of memorys of when I was young and had no choice but to fix it myself or walk. (times have not changed much lol)

[desoto1939]

Rich,

Why do you use #6 plug wire? It doesn't make any difference if you use #1 or #6, but I'm curious why. (This is only true on a 6 cyl. I don't know which cylinder pairs with #1 on a straight 8)

Dons coil wire idea would work too.

Because that what it says on my manual and service manual for my 39 Desoto. I have been doing this for the past 20 years and have no issue with the timing and the running of the car.  It might be different for other years but plu wire 6 works for me.  I will try to find the section in the service manual and post it.  I can get my car to be smooth on 2 degrees before TDC. 

 

ALso on the Number six cylinder on the head there is a small bolt that you can remove also to do timing with the old miller timing light so that is also why I use number 6.

 

Rich HArtung

Edited April 7, 2014 by desoto1939

[Dave72dt]

Putting it on #6 keeps the leads a little farther away from the fan blade, if that's a concern.  Putting the pickup lead on the coil wire may make it brighter but doesn't it pick up EVERY firing pulse when you do that.

[DonaldSmith]

Two revolutions per cycle, six cylinders...  If the timing light is connected to the coil wire, the timing light would flash three times per revolution.  You could still read the timing marks OK.  

[Don Coatney]

Putting it on #6 keeps the leads a little farther away from the fan blade, if that's a concern.  Putting the pickup lead on the coil wire may make it brighter but doesn't it pick up EVERY firing pulse when you do that.

What firing pulses does it not pick up?

[Dave72dt]

Putting it on a plug wire would only pick up that single firing impulse every two engine revolutions. Putting it on the coil wire would pick up 3 per engine revolution on  a 6 cyl.  I don't know why it would be brighter other than getting so many more flashes from the light per revolution it appears to be brighter.

[Don Coatney]

Dave;

 

With 6 pulses per 2 revolutions the target area is much brighter than one pulse per 2 revolutions. Also you get one correct pulse for every revolution when using the coil wire. So in effect you double the number of correct pulses.

 

But I still do not understand what firing pulse it does not pick up???