Holly 2V

[kmongar]

1995 VP 5.0FL SX Cobra

Hello,
Maybe someone can help me before I spend a couple hundred for a new carburetor. I rebuilt the Holly 2 barrel carb and it all seemed pretty simple. But when I re-installed it the motor did not want to start and would only start with the throttle plate open pretty far and then it barely ran with a cloud of black smoke. It seems as though the bowl is not filling and the gas is just leaking into the intake. I have had it apart several times and cannot find any apparent problem that would cause such a leak. And I do not see any check valve or ball on the diagram that could have blown out when I was cleaning it. Any suggestions?
thanks

 

[WizeOne]

Re: Holly 2V

What was it doing before you rebuilt it?

Excessive fuel could be from too high a fuel pump pressure, from mis-adjusted floats or worn out needle and seats. Another biggie with Holleys could be a ruptured power valve. It only takes one backfire, up thru the carb, to rupture it.

When that happens, you look down the venturiis at low speed and it is soaking wet. As you throttle up it leans out a bit and things begin to look drier down over the butterflies.

Those are just some possibilities that come to mind. There may be more. I am not an expert, just have enough knowledge to be dangerous.

 

[Maclin]

Re: Holly 2V

I doubt if you need a whole new carb, you probably just missed something in the rebuild.

I am not sure how far down you went, but a couple of things come to mind

Powervalve gasket not put it. It is a thicker asbestos type feeling gasket almost as big around as the powervalve, fits on the screw-in side of the powervalve on a boss just outside of the threads. If it is missing fuel will run right out of the bowl into the engine.

Torn diaphragm in the powervalve itself.

Metering block gasket missing or wrong one used between the metering block and the carb throtle body.

They are pretty simple, I am sure you will see it when you tear it down again.

 

[Don S]

Re: Holly 2V

When you "Rebuilt" it, did you dissassemble, clean (dipped and soaked in carb cleaner), blow out all the passages with compressed air, then reassemeble with all new gaskets, check balls, accelerator pumps, etc. and reset everything to specs.
Did you install a carb kit?

 

[kmongar]

Re: Holly 2V

Long story short:
-carb worked fine
-I made a bunch of other repairs...manifolds, cooling system, fuel pump
-when I put everything back together and tried to start the motor the carb bowl was was overfilling...fuel coming out the vent and leaking out the accelerator plate. ????
-so I took it apart and the float retainer e-clip was not there ????
-since I had it apart I put the rebuild kit in

-disassembled, cleaned and blew out with compressed air, new gaskets etc., there were check balls included in the kit but no mention of them in the manual and there are none shown in the diagram,
-adjusted float. etc.
-new power valve and gasket; I even took it back apart and put the old power valve back in with the same result
-new metering block gasket that was identical to the one that was in there

I know it is something simple and stupid but I'll be danged if I can see it.

 

[Maclin]

Re: Holly 2V

I know you are frustrated, you will get it figured out. You may need to back off from it or get someone else to look at it as well, even if they do not know that much about it. Talking and showing it to someone else might help you look at it form a different point of view.

Is it running out of the bottom of the venturi boosters, are they real wet? or way below them, like you can only hear it gurgling into the intake? If it is coming out the venturi boosters then that is another sign of the fuel bowl level too high, just not high enough to go out the vent tube. If it is coming out the venturis you should also be able to see fuel coming out of the sight plug as well.

If it is not coming out of the boosters or vent tube and is staying below the sight plug then I have to think it is something with the powervalve or its' installation. There could be two lengths of thread for the powervalves, this is just conjecture because I have not seen but one style of them. The powervalve gasket is pretty thick, maybe the threads are bottoming out somehow if a wrong gasket is being used.

There is a check ball in the bottom of the squirter housing. It needs to be there to keep the pump shot from tracking backwards, but would not have any bearing on your issue.

 

[WizeOne]

Re: Holly 2V

I hate carbs. Whoever invented the complexity and variations of them should be flogged with a cat o nine tails. Holley in particular, with all their variations and incomplete documentation as to specifically what is required for a given list number.

Grrrrrrrrrr!

 

[MikDee]

Re: Holly 2V

I hate carbs. Whoever invented the complexity and variations of them should be flogged with a cat o nine tails. Holley in particular, with all their variations and incomplete documentation as to specifically what is required for a given list number.

Grrrrrrrrrr!

I've never had a problem with rebuilding many different carbs over the years, I've always had success, Except with Holley!

Ford = Holley
Ford sucks = Holley sucks!

 

[kmongar]

Re: Holly 2V

The gas is coming out somewhere below the venturi's...yes kind of gurgling out. The carb bowl is just not filling up. When I hit the throttle no gas squirts out.

where exactly is that check ball located?

 

[Coors]

Re: Holly 2V

If I remember right, the check valve holds gas in the acell pump, so it shoots into the venturi, not back into the bowl.
Seems a combination off things; pump, maybe float stuck/too high; wrong gaskets.

 

[Coors]

Re: Holly 2V

Has to be wrong gaskets, first place to look. Did the give you several different gaskets that can go in the same place? Did you keep the old ones?

 

[Maclin]

Re: Holly 2V

The check ball is under the squirter nozzles housing. You need it for correct accel pump shot operation but that is the least of the problems right now.

I agree with coors (the man, not the beer!) on the gaskets. I also feel it is not assembled correctly in one or more areas.

Not squirting out the nozzles is can be caused by using the wrong metering block gasket. The accel pump supply is right on the bottom of the fuel bowl so I cannot imagine it not having enough fuel for a squirt even if the bowl is not geting filled. It is also easy to get the accel pump lever on the wrong side of the throttle lever and the pump would not work then either.

Here is a pic of a 4bbl Holley, basically yours is the front half of this. The squirter nozzle assembly with check ball is shown, the check ball is part #2. The power valve with gasket is part#12. The accel pump mechanism diaphragm and spring are parts #7 an #8. This is a very general representation of the parts, the kit you used should have a more detailed explosion.

This pic is from the Doug Russell Marine online parts catalog.

 

[kmongar]

Re: Holly 2V

Thanks for all the responses:
You are all confirming the things that I thought I should be checking. I had double checked:
-correct metering body gaskets
-float needle/seat and gas flow path clear
-float adjusted correctly per the manual
-fuel valve and gaskets in place
-accelerator pump rod on correct side of throttle lever
-power valve and correct gasket in place...tried 2 different valves/gaskets

QUESTION: is there a rubber o-ring or seat at the bottom of the fuel valve? It does not show one in the Volvo Penta 2V diagram but I have another diagram of a model 2300 from the Holley website (probably an auto carb) that shows a replaceable "fuel valve o-ring seal". My VP manual does not mention it either.

anyway, thanks again for all the comments. I will take it apart again and re-confirm gaskets etc. ...I obviously have missed something!

 

[Maclin]

Re: Holly 2V

Fuel Valve o-ring sounds like the one on the needle and seat assembly.

 

[kmongar]

Re: Holly 2V

yes the "standard" 2300 shown on the Holley website shows the replaceable "0-ring seal" for the fuel valve...but the whole fuel valve valve assembly is also different...this apparently was the automotive version. The Volvo Penta 2V diagram does not show an o-ring seal below the needle and their manual does not mention it either.

So apparently the marine version was built a little different than the auto version. I have been trying to get the detailed marine diagram from Holley but they have been giving me the run-around. Doesn't sound like they even know.

 

[Maclin]

Re: Holly 2V

Holley went on a buying binge in the 90's and lost track of their roots, it about put them out of biz.

I have a link for you to try for a pic and parts listing, although the parts listing kind of lumps everything together as part of the "repair kit". The pic may be closer to what you have, but these carbs are almost all the same.

The pic has a lot of detail, so if you save it onto your PC and open it with Windows viewer or something similar and blow it up you can see more details.


http://www.dougrussell.com/partscatalog/volvo_omc/index.cfm?fuseaction=comp&group=1436&GroupList=1435,1436,1437,1438,1439,1440,1441,1442,1443,1444,1445,1446,1447,1448,1449,1450,1451,1452,1453,1454,1455

 

[kmongar]

Re: Holly 2V

thanks for the diagram....that is the same as the volvo penta diagram I have. Note that there is no "0-ring seal" shown under the fuel needle valve. (Seems like there should be one there.)

There is only one small thing on both diagrams that I cannot identify. There is a short/straight 'something' shown between the metering body and the metering body gasket... at the bottom just above the "connecting line". It is not labelled and...???

 

[Coors]

Re: Holly 2V

It might be a little "***", to position the gasket.

 

[Maclin]

Re: Holly 2V

Beats me, doesn't look like a real part though. I know there isn't anything like that in the carb right there anyway.

The only way for fuel to get into the throttle body is thru the metering block. And the symptoms you describe are classic powervalve problems. That "cave" in the bottom of the throttle body is open to the intake plenum and is how the powervalve gets manifold vacuum enough to stay shut. When the vacuum drops below its' threshold the powervalve springloaded center moves back towards the fuel bowl (opens) and allows fuel to pass thru the powervalve passages and into the power enrichment passages in the metering block and on up to the venturi boosters along with the normal jetted flow. But the powervalve does not let fuel past it's diaphragm or it would just dump right into the intake. Like yours is doing. So it has to be something right there causing the problem. Incorrect powervalve or powervalve gasket, or the metering block is cracked. As for that diaphragm, it does not take much of a snort back thru the carb to damage it.

All luck to you on this.