|
|
Post by 47cj2a on Mar 20, 2020 10:06:28 GMT -5
Hi all
I have a Stock 134 flat head with a carter WO rebuilt
it starts, runs, idles, and drives great.
buuuuuuut when i shut it off the fuel line and pump itself retains enough pressure to PUSH fuel though the carb. sometimes a lot so it runs out the linkage rod onto the manifolds..... big fire hazard.
how have any of you solved this issue? i am at a loss.
thanks
pic for ref
 |
|
|
|
Post by Scoutpilot on Mar 20, 2020 11:24:41 GMT -5
Looks like you may be missing the heat riser valve in the exhaust. I don't see a PCV either. Both are critical. The heat riser controls the temperature to the carburetor. If it is stuck open, or worse missing, exhaust heat will cause the fuel in the bowl to boil. The pressure from this action will force fuel past the metering rod jet. The PCV, as well as ventilating it, regulates the pressure in the crankcase. Higher pressure means higher heat.
|
|
|
|
Post by brucew on Mar 20, 2020 19:25:10 GMT -5
 I think.... (Uh-oh, that sometimes gets me in trouble...) Higher crankcase pressure would result in higher fuel pressure.... BW
|
|
|
|
Post by Scoutpilot on Mar 21, 2020 4:07:15 GMT -5
Timing that is too far advanced will cause excessive heat.
Fuel mixture that is too lean will cause excessive heat.
An improperly assembled fuel pump will create excessive pressure.
|
|
|
|
Post by 47cj2a on Mar 22, 2020 11:44:52 GMT -5
my fuel pump just went out on me.
so i replaced it.
we will see if it was defective fuel pump all along. i think it might be.
|
|
|
|
Post by 47cj2a on Mar 22, 2020 11:51:14 GMT -5
Looks like you may be missing the heat riser valve in the exhaust. I don't see a PCV either. Both are critical. The heat riser controls the temperature to the carburetor. If it is stuck open, or worse missing, exhaust heat will cause the fuel in the bowl to boil. The pressure from this action will force fuel past the metering rod jet. The PCV, as well as ventilating it, regulates the pressure in the crankcase. Higher pressure means higher heat. i have a "vent to atmosphere" tube, so the crank case can breath ok.
i do have the heat riser (the flapper thing) in the exhaust manifold. it works perfectly.
im pretty sure pressure in the carb is from the line, not the bowl.
if i disconnect the rubber hose, fuel and pressure comes out of the hose, not the carb.
|
|
|
|
Post by Scoutpilot on Mar 22, 2020 13:01:08 GMT -5
It will come out of the line and not from the carb due to the closed needle and seat in the bowl. Can we please bring this whole conversation to one venue? It would be a lot easier.
|
|
|
|
Post by 47cj2a on Mar 23, 2020 0:23:23 GMT -5
the problem is that gas DOES run out the carb jets after i turn the motor off.
if i disconnect the fuel hose then it stops, but, fuel will still run out of the hose; under pressure
|
|
|
|
Post by Scoutpilot on Mar 23, 2020 5:27:41 GMT -5
Pull the carburetor. Take the bowl cover off. Remove the float. Inspect the tang that touches the needle for a deep scratch or gouge. Inspect the needle to make sure it has a pointed tip. With this condition, the needle will have a tendency to become "cocked" and won't close properly. Also, look at the float pin for grooving. Also, look at the twin posts where the pin slides through. Make sure the holes aren't worn excessively.
|
|
|
|
Post by 47cj2a on Mar 23, 2020 11:52:55 GMT -5
i did recently do exactly that.
everything looks great. i did a full rebuild with all new parts last month.
i did adjust the float tang and i feel like maybe it did help a little?
but all of the components seem perfect.
i just put the original fuel pump (from the 40s) back in the jeep (rebuilt) so with any luck, that should solve the fuel pressure issue. but i will drive it around more later and check
thanks!
|
|
|
|
Post by 47cj2a on Mar 31, 2020 18:27:56 GMT -5
the new fuel pump does not push pressure!
so that is good.
but fuel still floods out of the jets after shut off.... and it pools on the butterfly valve.... and it runs out of the rod onto the manifold posing a huge fire hazard.
WHAT AM I MISSING?
|
|
|
|
Post by Scoutpilot on Apr 1, 2020 4:18:39 GMT -5
There is only one more possible problem. The bowl/main body is cracked internally.
|
|
|
|
Post by 47cj2a on Apr 1, 2020 12:28:49 GMT -5
well i will pull it apart and check again. it looked fine when i was rebuilding it....
if it was cracked though, would it not run rich all the time?
the plugs are all a perfect tan.
|
|
|
|
Post by brucew on Apr 1, 2020 13:23:23 GMT -5
the new fuel pump does not push pressure! so that is good. No, it’s not. B-dubya |
|
|
|
Post by Scoutpilot on Apr 1, 2020 14:23:19 GMT -5
If it is cracked internally, you probably won't see it.
|
|
I think.... (Uh-oh, that sometimes gets me in trouble...)