79 20r Fuel Mystery
#1
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79 20r Fuel Mystery
I have a 79 Pickup dually flatbed that has been used on the farm for as long as I can remember. It has been sitting for a while and I decided to get it back out working again. I couldn't get it to fire so I traced the problem back to a worn electric fuel pump that someone had put on. I replaced it and put in a new rubber hose and filter. I have fuel all the way to the carb now but it stops there.
I can pull the line off of the but/hose fitting that goes into the carb and I have great pressure there. For some reason the fuel will not go beyond that point. I put an air hose on there to see if something was blocked in there but I can't get air to blow in either. I am not sure where to go from here.
If I put fuel directly in the carb it runs perfect until it runs out. So my problem is something internal within the carb itself but I don't know what. When I pump the gas I can hear suction but no fuel to be had. TIt looks like there is a float window on these. I can see no fuel in there.
Stuck needle? Is there a cutoff solenoid on these? I work on old carb tractors all day but I must say this carb is intimidating. I don't know what half the stuff is. Any suggestions?
I can pull the line off of the but/hose fitting that goes into the carb and I have great pressure there. For some reason the fuel will not go beyond that point. I put an air hose on there to see if something was blocked in there but I can't get air to blow in either. I am not sure where to go from here.
If I put fuel directly in the carb it runs perfect until it runs out. So my problem is something internal within the carb itself but I don't know what. When I pump the gas I can hear suction but no fuel to be had. TIt looks like there is a float window on these. I can see no fuel in there.
Stuck needle? Is there a cutoff solenoid on these? I work on old carb tractors all day but I must say this carb is intimidating. I don't know what half the stuff is. Any suggestions?
#3
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I agree.....I just rebuilt mine for the same reason....was my first time and it does seem intimidating at first but trust me, once you get into it it really is very easy....I got a rebuild kit from Autozone for $36.....take the top off the carb and dive in....my float bowl was full of crap and power needle was stuck shut....now she runs amazing....a good diagram of the carb comes with the kit.....just don't be in a hurry and take your time, its worth it........Kevin
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a good diagram of the carb comes with the kit.....just don't be in a hurry and take your time, its worth it.
#5
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I did it over a period of 2 days....probably 1.5 hrs each day so 3 hrs total....I took my time cause I didn't want to rush and screw it up.....no special tools needed.....I did it without removing the carb which makes it a little harder in hindsight....just have to be careful handling the small parts, you don't want to drop them into the abiss of the engine bay/garage floor.....
#6
I have a'74 (18R-C engine) & a '75 (20R) and they served me well, but both had intermittent stalling/no power problems that were fixed by removing a very small plastic screen just inside the fuel inlet. It's about 5/16" high and 1/4" wide, it filters the gas just before it hits the needle & seat. I have no idea why they installed this, there's an in-line fuel filter that is many times larger, and many times EASIER to service, it (the gas filter) is just before the fuel pump (on the 18R) and about on the same area on the other. I don't think you can access the screen through the inlet, (but maybe...) I removed the top of the carb, remove the float, and unscrew the needle & seat assy from under the top, it will be sitting right inside. Put it under your pillow for the Toyota fairy!
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