High end miss??

[Robbrob]

My car is a 1951 dodge meadowbrook with a 230 inline 6. It has a high end miss and won’t rev out the whole way, acts like it has a rev limiter and will only go about 50 mph now. I’ve replaced the points, condenser, cap, rotor, and spark plugs thinking it was an ignition related issue and it hasn’t fixed it. Now I’m starting to think it’s a carburetor issue. Has anyone had any issues like this?

 

Also I tried 2 other carbs on it and it didn’t help but the carbs I put on it were sitting for years so I already about figured they wouldn’t help but I gave it a shot anyhow.

 

A lot of the wires on the car are cloth insulated and it’s all falling apart so it may be shorting out somewhere, but Is there any reason why it would only short out at high rpm and at the same rpm all the time?

 

the car has a stromberg BXVD-3 on it

 

thanks

[Sniper]

My first thought was not enough dwell, but I suppose you could be drawing the fuel bowl dry, weak fuel pump.

[Plymouthy Adams]

do ensure you are not experiencing points bounce with not positioning the tension spring correctly.

[JohnS48plm]

Does  your throttle linkage open the throttle plate all the way open?

[DJK]

Did you check your pts. setting with a dwell meter? Are the small wires w/in the dist. frayed and shorting to ground? 

[TodFitch]

A weak coil could cause symptoms similar to what you describe.

[kencombs]

Is it truly RPM limited or just falters under load.  

 

Fuel flow related issues usually appear only under load, like it will only do 50 MPH.  If that's the case, first stop would be fuel delivery issues, filter partially clogged, pump weak, float to low etc.

 

Rpm limited would be like it will only do xxxxrpm when reving in neutral.  Lack of proper dwell, gap setting, worn shaft bushing, weak/misplaced points spring maybe.  Or, coil problem, but not as likely.

[Robbrob]

Yes it does it under load and in neutral.

[Robbrob]

I have not checked it with a dwell meter

ill have to find one and check it.

[rallyace]

The first things that I would check are timing, points, and vacuum advance.

[Los_Control]

Something easy to check is side to side movement in the distributor shaft .... Shaft rides on bearings, they wear down the shaft wobbles & the point gap/dwell changes.

 

I had a off topic car 1992 Dodge Shadow convertible. .... It had a oil drinking problem when we bought it so sent it off to rebuild the engine.

It ran really good after that but was your typical Grandma's 4 cylinder engine. About 6 months later the fuel pump quit working & replaced it.

 

The new fuel pump was like night & day, now when you stepped on the gas it would down shift wind up like a top and rocket off into the next gear .... was a kick in the pants to drive.

The old worn out fuel pump simply could not deliver enough fuel.  .... Was like having a governor installed. It simply ran out of gas, while still running satisfactory.

Just a thought.

 

Another challenge on these old distributors with positive ground. The wire under the cap connecting the points to the distributor body is cloth covered.

If your vacuum advance is working and the points plate rotates A bare wire could touch the distributor body & short out ..... very important this wire has good insulation.

[desoto1939]

Alot of people have said timing, point, condenser etc.  How old is the breaker plate assembly in the distributor body.  Remember there are two sections and these two section pivot on top of each other.  They do wear out and get sloppy from just normal wear.  Pull the dizzy cap, pull the rotor. then grap the breaker plate and see if you can wiggle the top plate with some movement.  

 

A friend came to my house and drove his 39 Desoto from Maryland and was also having  ignition issue and running rough.  Drove the car to my good old mechanic and he checked the above steps and yes it was the breaker plate assembly was worn out.  Came back to my house replaced the Breaker Plate with a NOS one and this solved his issue.

 

Just passing this along as a possible solution.  Also if this is the issue then look for a NOS breaker Plate for your car becasue it will have all the components assembled and then you have  complete spare unit in your parts box inthe car with all of the small wires and jsut plug and play.

 

Rich Hartung

Desoto1939@aol.com

[Robbrob]

Ok so I haven’t been able to work on the car for the past couple days which is why I haven’t replied, but I just put new plugs in it tonight because the car quit running and they were pretty black

 

i got some non resistor plugs and put in it and it fired right up and when I rev it it still misses but it seems to be higher in the rev range. 
 

so my question is this, if the dwell time is in fact too short (I still haven’t found a meter to test it so I’m not sure if it is) could the resistor in the old spark plugs coupled with the lack of time for the coil to charge make the effect of the short dwell worse? 

also on a side note what oil should I put in the oil bath air cleaner is straight 30 weight ok?

 

thanks for the advice I really appreciate it

[nonstop]

Try another condenser.  The new ones suck.  I have more than I can recall go bad across all brands in the last few years.  I now carry spares in my cars.

[Robbrob]

Oh believe me I’m on probably the 4th one thinking I was getting bad condensers.

 

is there a reputable brand that makes them anymore? The ones I have are all the parts store brands.