No gas in float after rebuild...here's why (1 Viewer)

FirstFJ60

SGT. Lincoln Osiris
Joined
Oct 16, 2017
Messages
275
Location
virginia Beach
I have a 84 with orginal Aisin carb. I got a carb rebuild get from Bap Geon here in Va Beach. I put the carb back on and it started back up after pouring gas in the chambers. It ran for about 10 min and I was happy like pig in mud. I came back out the next day and it wouldnt start. I noticed there was no gas showing in the carb window. I took off top of carb while on the truck (very easy to do). I looked at the plunger under the float hinge and took it out to see if i forgot the washer. I saved my old one just in case and compared it and quess what...NOT the same. The pic below is the one that came in the new kit. The old one has holes for the thing that screws into the carb too allow fuel to go in the float chamber. Because there were no holes no fuel would flow. Even the plunger was not the same. I guess the pic was for a FJ40 Carb. If you do a rebuilt for an 84 please look to see if the kit has holes on the piece to the left of the plunger. I out it back on and saw gas in the window and she fired up. Thanks to Pinheads video on youtube...made the rebuild a lot easier.
20210117_163906.jpg
 

g-man

SILVER Star
Joined
Sep 5, 2006
Messages
3,025
Location
Charlottesville VA
that's a needle valve and seat. Plunger is part #2 and goes with the accelerator pump...ie moves up and down when your pump the pedal. The black rubber tip on the needle in your image seems worn. Is that what you pulled out of your carb after they allegedly rebuilt it?

When the fuel in the bowl starts to get used up the float lowers and pulls the needle valve out of the seat so fuel from the pump/line will come in...until the float levels and closes the needle valve. Seems like the float and/or needle valve was stuck closed. Did running it cause the fuel to get used up and not replaced? Or did sitting overnight ...and a leak somewhere?

Not sure what the holes are there for ( you said yours had holes in the valve seat) ... but I'm positive the fuel coming from the pump and line are going thru the center bore of the seat to the needle and is the main feed of fuel to the bowl.

Image with name of parts for help with this thread:
1610923734788.png
 

FirstFJ60

SGT. Lincoln Osiris
Joined
Oct 16, 2017
Messages
275
Location
virginia Beach
that's a needle valve and seat. Plunger is part #2 and goes with the accelerator pump...ie moves up and down when your pump the pedal. The black rubber tip on the needle in your image seems worn. Is that what you pulled out of your carb after they allegedly rebuilt it?

When the fuel in the bowl starts to get used up the float lowers and pulls the needle valve out of the seat so fuel from the pump/line will come in...until the float levels and closes the needle valve. Seems like the float and/or needle valve was stuck closed. Did running it cause the fuel to get used up and not replaced? Or did sitting overnight ...and a leak somewhere?

Not sure what the holes are there for ( you said yours had holes in the valve seat) ... but I'm positive the fuel coming from the pump and line are going thru the center bore of the seat to the needle and is the main feed of fuel to the bowl.

Image with name of parts for help with this thread:
View attachment 2556380
Thanks for the education. The one in the pic was the new one. My old needle valve seat had holes in them. When i installed the new one it didnt work. I set the float height per manual. Im not sure what went wrong. I will check it out tomorrow and lets see. Do you have a theory has to why the new Needle Seat valve needle valve spring pin didnt work.
 

g-man

SILVER Star
Joined
Sep 5, 2006
Messages
3,025
Location
Charlottesville VA
Make sure the float moves to the specifications shown in the FSM. Make sure the needle valve isn't sticking in the seat. Make sure the rubber tip on the needle is smooth...not worn, cracked, cut or deformed. Any deformity could be causing it to stick. Most rebuild kits come with a small paper ruler with mm markings. Don't need a SST aka special tool, just a large flat head to screw in the valve seat.


1610926904525.png
 

g-man

SILVER Star
Joined
Sep 5, 2006
Messages
3,025
Location
Charlottesville VA
Did you run the bowl dry? Find out if running the truck uses up the fuel in the bowl and if the needle valve is stuck ...then the fuel is not being replaced.

Or, did the fuel leak out overnight?

Or did the fuel evaporate because the carb fan doesn't work?
 

g-man

SILVER Star
Joined
Sep 5, 2006
Messages
3,025
Location
Charlottesville VA
when you flip the horn over and the float is down and the seat closed, you should be able to lift up the float very easily. Like pinky finger.

Also just a thought but the needle seat are pretty high up in the bowl, so its not leaking out of the needle and seat , its just not refilling. Just a guess.

If you have a leak it would have to be from one of the 2 plugs that access the main jets they are below the sight glass on either side. I would think fuel would be visible outside the carb and fuel smell pretty evident too.
 

FirstFJ60

SGT. Lincoln Osiris
Joined
Oct 16, 2017
Messages
275
Location
virginia Beach
There is no signs of gas leaking...bone dry. I adjusted the floats level and lowered postion per manual specs. Also, when I had the rebuilt done with the new Needle Valve Seat I did notice gas didnt squirt out into the primary which made me take a look.
 

g-man

SILVER Star
Joined
Sep 5, 2006
Messages
3,025
Location
Charlottesville VA
If this was done after you drove it, maybe the float is stuck closed and not letting more gas in the bowl.

Gas squirting down into the venturi is done by the accelerator pump. When you work the lever on the side of the carb the plunger, or when you quickly pump the gas pedal. Failure to have gas squirting means there was probably no fuel in the bowl. A small trickle means the plunger in the accelerator pump is worn. And when this happens you have to pump the gas pedal more and more to get the truck to start. They should have replaced the plunger too with the rebuild.

You really need to figure out if its leaking out or is the gas being used up and not replaced because the needle valve and seat are stuck closed and/or the float is not dropping with the fuel levels. Ensure the float is not sticking on the float pin too. It should be smooth and cylindrical ...no flat spots, no corrosion.

.
 

g-man

SILVER Star
Joined
Sep 5, 2006
Messages
3,025
Location
Charlottesville VA
Many of these aftermarket kits are generic and have parts that will go into different toyota carbs. did you put your old needle valve and seat back in?
 

FirstFJ60

SGT. Lincoln Osiris
Joined
Oct 16, 2017
Messages
275
Location
virginia Beach
Many of these aftermarket kits are generic and have parts that will go into different toyota carbs. did you put your old needle valve and seat back in?
Yes...i put the old Needle valve and seat back in at it worked. Its squirting now into the primary. I will test it out tomorrow
 

FirstFJ60

SGT. Lincoln Osiris
Joined
Oct 16, 2017
Messages
275
Location
virginia Beach
Well i just tested it and it was a no go. It wouldnt crank. There was no gas in bowl...nor is it aquirting fuel in primary. My fan is working to nlow on carb. Im getting fuel to carb from main line. Im at my wits end.
 

g-man

SILVER Star
Joined
Sep 5, 2006
Messages
3,025
Location
Charlottesville VA
So not a sticking needle valve, but a slow internal leak until the bowl is empty. looking at this image all fuel ( in black) leading away from the bowl runs uphill at some degree.

By the way I don't think a bad fuel pump would matter...because the inlet is high on the bowl. That fuel shouldn't disappear. And if it's not leaking out externally and not evaporating that means and internal leak.

it is possible you have a hairline crack in the housing, possibly in the housing in one of the fuel passages where you can't see it and the fuel is dripping down the bore into the intake.


Did you soak your carb body in carb cleaner overnight when you rebuilt it? Did you blow out all the passages with compressed air?

You may have to source another carb body and put your parts into rebuilding it if all the above doesn't help.

1610989717742.png
 

FirstFJ60

SGT. Lincoln Osiris
Joined
Oct 16, 2017
Messages
275
Location
virginia Beach
So not a sticking needle valve, but a slow internal leak until the bowl is empty. looking at this image all fuel ( in black) leading away from the bowl runs uphill at some degree.

By the way I don't think a bad fuel pump would matter...because the inlet is high on the bowl. That fuel shouldn't disappear. And if it's not leaking out externally and not evaporating that means and internal leak.

it is possible you have a hairline crack in the housing, possibly in the housing in one of the fuel passages where you can't see it and the fuel is dripping down the bore into the intake.


Did you soak your carb body in carb cleaner overnight when you rebuilt it? Did you blow out all the passages with compressed air?

You may have to source another carb body and put your parts into rebuilding it if all the above doesn't help.

View attachment 2557050
Yes insoaked it in Berruman Carb dip over night and blew air in All Passages. My question is after i took the top part of carb off yesterday and replaced it...it fired up and fuel went into bowl and it was filled half way?
 

FirstFJ60

SGT. Lincoln Osiris
Joined
Oct 16, 2017
Messages
275
Location
virginia Beach
So i took off top of carb. As you can see by the pic 1there is a 4mm height difference from original plunger (left) to new rebuilt one that came in kit (right). Pic 2, notice needle valve seat is different. Rebuilt Kit parts is not the same as original parts. I do notice screen under needle valve seat is little clogged
Pic 1
20210118_133344.jpg

Pic 2
20210118_134455.jpg
 

g-man

SILVER Star
Joined
Sep 5, 2006
Messages
3,025
Location
Charlottesville VA
neither of these ^^^ issues is causing the bowl to empty. And neither is going to affect how the carb runs significantly.

What if you removed the carb. And leaving the horn off, filled the bowl with water. Leave it sitting on a table with paper towels under it and see if you can figure out where it's leaking.
 

FirstFJ60

SGT. Lincoln Osiris
Joined
Oct 16, 2017
Messages
275
Location
virginia Beach
neither of these ^^^ issues is causing the bowl to empty. And neither is going to affect how the carb runs significantly.

What if you removed the carb. And leaving the horn off, filled the bowl with water. Leave it sitting on a table with paper towels under it and see if you can figure out where it's leaking.
Ok....great idea. .i will do that.
 

FirstFJ60

SGT. Lincoln Osiris
Joined
Oct 16, 2017
Messages
275
Location
virginia Beach
Ok...so, I took it off and filled the bowl up with gas and there was no leaking for two days from the bowl. I sprayed carb cleaner again in all he inlets and inspected everything and did notice the gap from the needle valve to float was more than 1.1mm (per FSM)...so I adjusted that correctly. I've noticed that this is the fourth time I've taken the top off and when I replace it, the bowl fills up and it fires up but after a day, there is no more fuel in bowl. I will see if gas leaves the bowl.
 

ToyotaMatt

Factory Focus-Point Mind-Set Approach
Supporting Vendor
GOLD Star
Joined
Aug 12, 2007
Messages
14,178
Location
EAST COAST
Ok...so, I took it off and filled the bowl up with gas and there was no leaking for two days from the bowl. I sprayed carb cleaner again in all he inlets and inspected everything and did notice the gap from the needle valve to float was more than 1.1mm (per FSM)...so I adjusted that correctly. I've noticed that this is the fourth time I've taken the top off and when I replace it, the bowl fills up and it fires up but after a day, there is no more fuel in bowl. I will see if gas leaves the bowl.
idle mixture screw shipped ............ :)
 

2mbb

SILVER Star
Joined
Sep 1, 2003
Messages
5,135
Location
WC, CA
Here is an interesting post on the carburetor bowl emptying:

 

Users who are viewing this thread

Top Bottom