YF Flooding

My 1bl YF just started flooding out while driving. I rebuilt it last summer, it has run great since.... till the other day. The fuel filter is an inline see thru one. It normally runs about half full. It has been entirely full twice now. The jeep floods and won't start. I disconnect the fuel line from the pump and empty the filter. Start it up and it runs fine. Do you think my fuel pump is pumping to much fuel at a too high a rate or do you think the float is sticking? Any thoughts are greatly appreciated.

 

Float got heavy or trash in the needle and seat area would be my first 2 choices. Make sure choke is opening all the way.

 

Can you give us a little more information please, What engine do you have........Is the carb the original unit or is it a transplant from another rig..........Is the flooding problem consistent and predictable under certain conditions or intermittent and random...........Has the fuel line from the pump to the carb been re-routed from its original location...........Does it just die from a high fuel level in the float bowel or does fuel run out the carb all over everything........Have you recently replaced the fuel pump........are you sure its flooding and not vapor locking.

If it has been running ok for some time then just starts flooding I would start by making sure the float is not fuel logged, There is not some dirt in the needle seat of the fuel valve, Float is properly adjusted and would take a good look at the needle and seat of the fuel valve.........Is the needle/seat worn or damaged ( i think your model year used the viton tipped needle ), Is the little gasket under the fuel valve blown or missing.

If the carb is adjusted properly and parts are good, Fuel line routed to carb properly and it still floods it would not be a bad idea to put a pressure guage on the feul pump so you know for sure what you are working with before going much farther.

Hope this helps get you started.

 

Carb is original as is the 258 it sits on and the flooding seems to be intermittent. Last week when the problem surfaced for the first time it was cool and raining. The fuel line is in the original location. As far as dieing it is hard to tell for sure but when I remove the air filter the top of the carb has gas all over it. The fuel pump was replace because it was leaking approx a year ago. I ordered another rebuild kit today. Gonna take it apart and check the float and needle and seat out.
Do you think it could be vapor lock?

 

If there's gas on top of the carb, that seems like a stuck float. Better to have the engine flood out than to ignite a pool of gas.

The fuel pump only admits as much fuel into the carburetor as the float will let it. Draining the filter should not have any effect. You have the stock mechanical pump, not an aftermarket electric pump, yes?

Have you taken the carb apart?

 

Yes, I have the stock style mechanical pump. I haven't taken it apart after the initial rebuild 6 months ago. Plan on doing that saturday.

 

I agree with timgr, Sounds like the float and possibly the needle seat assembly is the place to start.
Do you have a soldered brass float or the black foam/composite type? The float could have become fuel logged.
I am not thinking vapor lock at this point.

 

It is the soldered brass one. I will take it apart tomorrow. I will let you all know what I find. Thanks for the advice.

 

my flooding was a choke issue. the choke was not coming unchoked when the engine was warmed up.

 

Yeah, I put a hand choke on it a couple years ago. That is working fine.

 

Well, I spent most of the day working on the jeep. Rebuilt the carb. That wasn't it, it still does it! I took the HEI dissy out and put the old point distributor back in. I think that may have taken care of it. I will take it out for a test run again in the morning to know for sure. If that turns out to be the problem I guess I will find out how to replace the electronics in that. Anyone had any experience doing that?

 

Thats interesting, Sorry all of us spent so much time thinking it was carb related. I dont have any useful expertise with HEI.
Hope you get it figured out soon.

 

Well, Back to square one!! Drove it around this morning, at first everything was fine. This is the stock points distributor mind you. When it warmed up good all heck breaks loose again. It coughs, spits, sputters and even backfires. I am at my wits end trying to think what it could be. Could the timing have jumped and still be able to change distributors and get it running? I know when I put the distributor in the rotor was more towards 3o'clock maybe 3:30. I didn't think it mattered as long as I routed the spark plug wires correctly with the firing order. When the problem isn't exhibiting itself it runs good.

I don't have a different carb to through on it to rule that out entirely, but it seemed to be fine when I took it apart yesterday. I threw the new accelorator pump and needle and seat in anyway.
Anyone run into this before with your 258?

 

re-check the float position and the needle/seat assembly. even a tiny piece of debris/dirt will make the needle unable to close, allowing the bowl to overfill. high float will allow the same thing. also, a loose valve assembly will allow fuel to flow into the bowl, too, even though the needle seats firmly.

good luck.

 

Not sure about the YF, but the 2100 float will hang and flood if the float tang is not perfectly level. I'd suggest you take the float out again and look at it from every angle to make sure the mounting and tang are straight and level. Carburetors can be very fiddly ...

 

Ok, I'll give it a try. Took the day off to work on it. Got to try everything. Any other good ideas?

 

I am still contemplating possibilities, Just throwing some things out there, Is there anything else besides the carb that has been worked on or changed recently?
I gather from the posts that flooding is still the primary issue, Still getting fuel all over the top of the carb?
You mentioned Backfiring, Is it through the intake or exhaust?
What other equipment does your engine have? Do you have an EGR Valve? Is it controlled by a CTO Switch? Do you have a stock air cleaner with the TAC System?
If your distributor has a vacuum advance unit is it also controlled by a CTO Switch? Is it possible the ported vacuum got reversed with the manifold vacuum at the CTO Switch and the timing accidentally got set with vacuum applied to the distributor?

Timing thats off should not contribute to flooding but could instigate Backfires.

just trying to help with the process of elimination until we can corner the real gremlin, you may have a combination of problems.

 

No nothing was worked on recently. It has been running great. No more flooding. The backfiring is through the exhaust. I took yesterday off from work to continue this saga.
As far as equipment goes, it has none of that anymore except the egr valve at the side of the exhaust manifold. I think it is now solved, not sure of course till I drive it a while, but believe it or not I found a loose wire connection. Of course it had to be the main feed to the fuse block. But before I found it I fried at least the coil on the HEI. I get no spark from that. When I took the coil off it was hotter than heck.
If it is not fixed I will start a new thread.
Thanks for everyone's help.

 

i don't know, flooding is usually a fuel delivery issue, rather than a spark/timing/electrical problem. of course, having spark/timing/electrical problems can exacerbate carburetor issues, but if you're getting a regularly flooded carb, it seems that's where the issue is.

no amount of timing adjustment, or hotter spark, or "cleaner" wiring is going to absorb too much fuel delivery. just saying i'd still be looking at something in the carb.

wally

 

I agree with wally, I would keep an eye on the fuel delivery angle while chasing down gremlins.
My old FSM lists the following as primary causes for backfiring through the exhaust.
1. Air leak into exhaust manifold.
2. Faulty diverter valve.
3. Faulty choke operation.
4. Exhaust leak.

Hope you get this nailed down soon.