345 no start...fuel issue

[creeper]

I have a stubborn 345 that was running before my 3 month brake job...I kept starting it but ignored the darn thing for a month or more and now she won't start. Symptoms:
-the engine starts up but only runs on the primed fuel I put in the bowl
-the carburetor was just rebuilt and I checked that it is getting fuel in
-the engine acts like it is out of fuel or cut off and just quits when it runs out of the primer fuel

right now I plan on tapping the metering box with a rubber mallet while turning it over to see if the float is stuck. If that doesn't work I was thinking of taking the metering box off and seeing if the float is really stuck...is this the right path to take? I am getting spark and it was running before. I have not gotten around to timing this beast yet so I have not idea what the dwell is or the timing is since this is what I was going to do once I got 'er to start up.....I was all motor and no brakes now I'm all brakes and no motor...

 

[Robert Kenney]

Have you verified that your fuel pump is making fuel pressure to the carb?
If it is recheck your float drop and that while it is in the dropped position verify flow past the bowl inlet valve.

 

[creeper]

have you verified that your fuel pump is making fuel pressure to the carb?
If it is recheck your float drop and that while it is in the dropped position verify flow past the bowl inlet valve.

Thanks. Yes, I verified that the pump is getting fuel to the carb right off and hence my thought toward the carburetor. I will figure out where the inlet valve to the bowl is on my holly 23xx carb and see what I get. Thanks again...

 

[Robert Kenney]

Depending on what 23xx you have the general location of the inlet valve is above the float on the pivot end. See marked up photo. Assumming the bowl is empty and the float is in the dropped position, you will be able to test that air will pass through the fuel line connection it to the carb. Don't use high pressure compressed air.

 

[Bill Bennett]

Good picture of the carb. Some of the 2300 carbs have a very fine mesh screen behind that brass fitting. It wouldn't take much to plug the screen and prevent - or restrict, the fuel flow into the fuel bowl. If you use a 'in-line' fuel filter, that screen can be removed.

 

[creeper]

Okay, at the end of the day yesterday my father in law had me talked into loosening the metering bolts to remove it and we stopped. I only loosened two of them but didn't back them out. If you look at my photo I loosened the flat head bolt screws on the metering block at a and then opened the top of the metering block at b to see if fuel was coming throught the inlet valve. It did so I closed it up at b and fired up the truck after a few light taps with the back of my hammer on the metering block to help loosen up the float. The truck fired up and ran well but fuel is now coming out of the back of the metering block at c even after tightening the screws on the mtering block back down so I think me seal is out....looks like a trip to lj's for a gasket set....suggestions? Truck runs well and my brakes are done though....

 

[creeper]

Opps...the photo.

 

[Scoutboy74]

That carb is clean enough to eat off of. Yep, new reusable metering block and fuel bowl gaskets should take care of the leak. They'll be blue in color.

 

[Bill Bennett]

Don't know what to say about these 'so-clean carbs'!
For just information, the part between 'b' and 'c', is the 'metering block'. The part 'b', with the brass fuel line connector, is the 'fuel bowl', hopefully with a 'brass float'. There is 1 version of the first gasket and 2 different versions for the blue gasket for the 'back side' of the metering block. Either will fit but only one will work correctly. As the gaskets are not marked 'front' or 'rear', compare the existing gasket with the replacement and the difference is easily seen. The blue gaskets should be able to re-used maybe 4 times. After changing the 2 gaskets, the accelerator pump 'cam' should be moved to the #2 position and lever re adjusted for movement because the fuel bowl position has been changed. Replace the little washers under the 4 screws that hold the fuel bowl and metering block to the main body. They are available in nylon bulk pak and if not over tightened and cracked, can be reused. Will also suggest replacing the accelerator pump diaphram with the 'alcohol fuel' version. The ethanol damages the black rubber (gas friendly) version. The alcohol version is a 'yellow/green' color. You need the 30cc version. The acc diapram is on the underside of the fuel bowl, held with 4 small phillips screws.
Do you know how to make the accelerator pump adjustment?
If you replace the needle and seat in the fuel bowl, the base instructions should be with the kit. Final adjustment of fuel level is done with the motor running.
Read some threads on refreshing the 2300 carb. There is much more to learn. After the 3rd time, it gets much easier!

 

[creeper]

This carb is clean because it was rebuilt by mayben. I guess I messed up the new blue seal on the back of the metering block that he put on by backing off the screws and letting the motor run like that for a bit...anyway, I should be alright with just new seals since it was just rebuilt, eh?

 

[Robert Kenney]

this carb is clean because it was rebuilt by mayben.

This bit of omitted info could have simplified things for us. Why not give the guys trying to help you all of the nuts in the beginning. Nothing worse then a guessing game when all of the cards are not face up.
anyhow glad you are running again. The blue bowl and metering block gaskets are usually good for many loosening cycles. If you are sure things are right and you do need new ones in a hurry I recall seeing kits at the local auto zoo in the performance section.

 

[creeper]

@Robert...I did mention at the very beginnning that my carburetor had been recently rebuilt if you check my bullet points...anyway, this project has been ping ponging me from problem to problem for a while. It will be nice just to drive around the block for once. Thanks for all your help so far. I'll check the auto zoo down the street today and bring my holly into the shop I work at for a second opinion from my boss who's pretty good on carb's.....it's no fun to do a brake job and not be able to check 'em out 'cause your carb is acting up....oh, I forgot to ask my one last question...I pulled off the fuel bowl with the float assembly and its' blue gasket looked good. I did not pull off the metering block but was wonder if a few good taps with a rubber mallet and/or drift would set it free or not? I wish I had a blown up parts diagram for this carburetor...

 

[Scoutboy74]

I imagine this diagram is posted elsewhere in the carb tech forum, but in the interest of simplicity, here you go. Get used to the ping pong game. That's just life as a binder owner.

 

[Bill Bennett]

What you can't see on the diagram is the 'alignment pegs' on the other side of the metering body. Don't bang on the metering body to hard. They break off easy.

 

[creeper]

Thanks! I got the fuel bowl and metering block off yesterday and looked at it with my friend. It seems the fuel was not getting by the new blue gaskets mayben had installed but rather was exiting the hole on top the metering block that can't be seen while the block is attached to the main body. I guess my float was initially sticking in the up or full position and after freeing it up it got stuck in the down or empty float position causing the fuel to overflow out the metering blocks' relief hole (nicely hidden so a newbie will think it is the gasket). Anyway the valve assemble isn't shutting off/on so I went at it with a bit of wd-40 and cycled it a bit. I refiit the block and bowl and with any luck I'll have it on this moring at fist light...this time of year sucks for curbside projects. Thanks for the help so far I hope this sucker works right now...thoughts on the valve assembly? This should remedy itself as it gets going again eh? (the sticky valve assembly...)

 

[Robert Kenney]

The sticking float May very well be stale gummed up fuel and your working in some sort of solvent May have fixed it. The other good possibility is a small amount of contamination possibly in that area will hold the valve open.

On you other post, yes I did know the carb was rebuilt but what I didn't know was that michael did the work. That pretty much meant it was originaly setup correctly with respect to the float.

 

[Scoutboy74]

To rk's point about possible contamination, how are set up for filtration? The popular choice is two inline filters, one between tank and pump and one between pump and carb. Have you inspected the inside of your fuel tank recently? This e-gas is great for loosening crud particles which are then free to be sucked through the fuel lines. It does wonders on a freshly rebuilt carb.

 

[creeper]

I agree I most likely have crappy fuel...I looked for my inline fuel filter this morning that I bought but can't find it and will install a new one when I get it this Friday...I got the truck running 2/3 choke but it runs out of fuel with a noticeable gasp and dies when I go to let off the choke a bit...what does screw d and e do with respect to this problem if any? I see there are two holes my throttle lever can be mounted into which one is best? Also, there are two screws with springs at the base of the carb toward the cab...are these the idle adjustment screws? How should they be set initially? I ask sooo many questions because something is amiss and I have no idea what I'm doing...all I know is I lose gas when I let the choke off and it makes a noticeable gasping sound like it is in need of fuel as it dies....help

 

[creeper]

Here's my carb as setup currently...as far as what hole my throttle cable goes on.....etc.

 

[Scoutboy74]

Screw d is your curb idle speed adjustment. Screw e is your fast idle speed adjustment. It is engaged by the round metal cam when the choke is pulled out (closed). As the choke is pushed in, the engine speed will drop a corresponding amount until the choke is fully pushed in. The screws on either side of the carb rear are your idle mixture screws. Mayben likely would have set these up an equal 2.5 turns out from gentle seating, with the final lean best mixture adjustment being left up to you.
Double check this by screwing each of them in gently. Stop the moment resistance is felt. Then back them each out an equal 2.5 turns.
When you cold start the engine, you'll want the choke closed up nearly all the way to begin with. Pump the accelerator once or twice and key the starter. I don't know if you have a tach, but when the fast idle adjustment is set properly, the engine speed should be roughly 1600 rpms at full fast idle. This high speed is necessary to help keep the cold engine running. If your engine doesn't reach this speed when you start it with the choke engaged, turn the screw e clockwise until that speed is achieved. Allow the engine to run at near full choke for a minute or two before beginning a gradual reduction in choke. After about 5 minutes of run time, the engine should be sufficiently warmed to run without choke assistance. If the engine is turning very slowly or dies at this point, your curb idle speed screw d is backed out too far. When the engine has reached normal operating temperature (minimum 20 mins run time), set the curb idle speed to roughly 700 rpms +/- 50. Next begin slowly turning one idle mixture screw clockwise until the engine begins to stumble. Stop and back it off a 1/4 turn from stumble point. Do the same thing with the other screw. You May get as much as one full turn in before the stumble is induced. You want both screws to be the same amount of turns out. After this is done, recheck your curb idle speed and adjust as necessary to achieve @ 700 rpms.