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Trouble in Paradise

Started by chetbrz, July 13, 2020, 05:57:15 PM

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chetbrz

Well after 6 hours of engine runtime (over 6 months) the Vacuum fuel pump overflowed.  Could this be because I have been idling fast and low speed without being under load where there might be more gas usage per rpm. ??  Don't know just asking.

Once the pump filled to the brim it starved the carb for gasoline.  My assumption is that it could no longer gravity feed the gas to the carb with both chambers filled.  At this point no gas in the oil.

Anyone have any experience with an issue like this.

Chet...

PS... Gas cap vented so the issue isn't from expansion of the fuel in the gas tank.
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Russ T. Fender

If the float in the carburetor shuts the flow of fuel off as it regulates the level of the fuel in the bowl and the float in the vacuum tank does not respond by shutting the fuel flow from the tank it will do that.  I have never had a Kingston vacuum tank apart somI am not sure how it regulates the flow but with a Stewart vacuum tank it usually means a leaking float or a bad needle and seat in the vacuum tank

chetbrz

Quote from: Russ T. Fender on July 14, 2020, 09:05:39 AM
...  I have never had a Kingston vacuum tank apart so I am not sure how it regulates the flow but with a Stewart vacuum tank it usually means a leaking float or a bad needle and seat in the vacuum tank

Thanks Russ,  Your statement above shares the same opinion for those of us that have had the Kingston pump apart.  Unlike the Stewart pump which is designed to work with any engine and vacuum level.  The Kingston is specific to the Plymouth in that there isn't any clear means of stopping gas from pumping into the upper chamber.  There is no shut off valve like the Steward.   It gets its vacuum from the rotation of the oil pump which is directly proportional to the engine rpm's.  Current theory is that the pump is in equilibrium with the running engine.  The fact that when it overfills it inhibits fuel flow to the carburetor I can only conclude that the increased volume level of the gas eliminates venting which stops the flow.  Like putting your finger on a straw opening and lifting it out of the glass while trapping the unvented fluid.   It's and enigma at this point. 

Since it worked for 6 hours of idle runtime I thought that maybe the engine under load would require a tad more gas/rpm than an engine at idle.  Thus the pumps ability to be in equilibrium with the running engine would be challenged.  I have a Steward pump which would be 100% more reliable and it would add the following benefit:


  • The Steward works off the intake vacuum which would eliminate using the oil pump to create vacuum for the Kingston.  I would get faster positive oil flow at startup.  Currently the Kingston increases the time the engine runs before positive oil pressure.
  • At this point I believe the Steward would be more reliable over a number of different driving conditions.
  • I could put back the electric fuel pump but it has a tendency to develop two much pressure for the old carter brass bowl.
  • Changing to the Steward would be period correct but not original.  I think I will have to go this route unless someone can convince me that the Kingston won't leave me stranded miles from home.

Any thoughts on the issue greatly appreciated.  Chet...
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Crazydave

Really, you are the only guy that it will or won't bother.

My 2 cents, (coming from someone who hasn't tried to set mine up yet)

If you are strictly looking for reliably, electric pump is the way to go. If i ever do any regular street driving, I will have a hard time parting with it. Especially since I know my tank has rust in it and I don't trust the Kingston to pull through a filter or not plug up with sediment.

If you want to be correct, there is only one way  :) The Kingston's are rare, making the cool factor of having one in service more appreciated by us in the know. I guess i'm saying you're close, don't give up just yet, but its alright if you have to.

The guy who needs to chime in is Frank, 2 summers ago he drove from Minneapolis to Northville Michigan and back on a Kingston.


Russ T. Fender

I ran my 30-U daily from 1962 until 1972 when It developed a wrist pin knock.  During those 10 years I used a small electric fuel pump in place of the Stewart vacuum tank that had been put on by the original owner after the Kingston unit failed.  I was also running a Carter BB-1 carburetor.  Never had a hiccup!  I am now in the process of a restoration and have a rebuilt Kingston vacuum tank that I plan to use if possible but would not hesitate to switch to an electric fuel pump if I have any problems.  The electric fuel pump can be hidden and the line can be piped through the vacuum tank as I did with the Stewart unit.  People always commented on how quickly my car started and I never volunteered the fact that I had an electric fuel pump.  I am a purist but a practical one!

chetbrz

Russ,

That's how my car was setup prior to the rebuild. 

Dave,

I hear what you are saying.  I have setup the Kingston pump and will try again and see if the pump floods out.  If it does, I will do what Russ suggests.  I already have a second Kingston with this pass through setup.

Any and all other comments are welcomed. 
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frankp

Chet, sorry for your woes.  I'm trying to understand how it overflowed the outer can without gas being sucked into your oil, but no matter.

When my Kingston malfunctioned, it was a broken solder on the the top washer on the cork shaft.  This allowed the cork to rise higher than it should, resulting in higher gas level since the inner tank valve never closed.  There was always the "call" for gas.

You may want to disassemble your tank and see what's up.  Also check the inner valve, it must seal completely.

Hopes this helps.
frank p

chetbrz

Hi Frank,

You have me thinking (not an easy job).  I assumed that the vacuum pump failed because the engine started to stall and the only why I could keep it running was to chock the carburetor.  (First thought no gas.)  The vacuum tank over flowed when I attempted to re-prime it.  Obviously it didn't need priming.

I was looking at some old posts from a member that complained about a similar issue.  "Having to chock the carb in order to keep it running".  I don't believe he mentioned what the final solution was. 

Maybe it is my carburetor giving me problems ?  Need to look deeper.  Thanks.
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frankp

You may have debris in your carb?  As you know, won't run if too lean or rich.  Need that Goldilocks level of fuel/air.  Good luck!
frank p

chetbrz

Well,

After removing the Vacuum pump and checking the little there is to check I put everything back together and fired up the engine.  It started right away and oil pressure pumped right up to 40psi.  No problems with the carburetor. 

Maybe when I initially primed the pump I put to much gas in it.  This time I was a little stingy.  Very perplexing.

The only thing I can think of for stalling gas into the carburetor is venting to the lower compartment.  There is a track in the upper cylinder that allows air or gas poured into the prime port at the top of the pump to flow down to the bottom compartment.   I am theorizing that if the bottom compartment fills completely this venting ability might be greatly diminished thus limiting the flow to the carb.  Just a theory.

I left the top clamp screw a little loose so as not to close this very small vent space.  Or maybe it is designed this way to limit the amount of gas that can escape into the oil system.  There is so little info on the Kingston.

Frank I believe in your case the non vented cap on your gas tank created pressure in the gas tank that spilled over into your Vacuum tank and also the crankcase. 

Anyway time will tell and hopefully over a normal driving range the pump plays nice.
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frankp

Chet, glad you came to a resolution.

Note, I only slop a little fuel in the Kingston before attempting to start after winter storage to get a little fresh gas in.  Otherwise, it's good to go since the repair explained previously.  I close the valve on the line to the carb when parked for an extended time to minimize the force on needle valve/float.
frank p

chetbrz

Quote from: frankp on July 15, 2020, 12:46:49 PM
Chet, glad you came to a resolution.

Frank I wouldn't say resolution.  I think more like a half baked theory of what might have happened.  I really wish there was more info, or any info on the Kingston Fuel pump.  We'll see what the future brings.  Yours seems to work fine and its 90 years old.  If I continue to have issues I might redo the float.  Mine is 2" in diameter, the original was 1.5"  Also I made it a half inch smaller to compensate for the diameter difference.  It might suck to much gas in the upper chamber before dumping.  A little change like this might have unbalanced the pump.

Chet...
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Russ T. Fender

I have what is supposed to be a completely rebuilt Kingston vacuum tank. It was rebuilt by a gentleman who was supposed to be the only one who would work on them as none of the other guys who restore vacuum tanks want to have anything to do with the Kingstons.  I am probably six months away from getting my car running again but hope that I can use my Kingston vacuum tank as intended.  The rebuilder told me they worked fine and were quite reliable but they were not very forgiving.  They had to be set up right or they were problematic.  I unfortunately can't remember his name but he had spaces in the chocolate field at Hershey.  He was there last year but no longer rebuilds vacuum tanks.

chetbrz

Hay Russ if you remember his name that would be helpful. As far as rebuild is concerned there is the float and the trap door.  That's it.

As far as installing the copper vacuum line it shouldn't be larger than 1/8" copper tubing.  Gas line 3/16" copper tubing.  My car hasn't been driven yet just 12 hours of idle time on the drive way.   Need to get on the road for a real test.
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