hi, I just got a 1974 comet and it had a fuel leak under the bowls, so I rebuilt it and everything started fine and ran good, but when it came to hitting the accelerator it will fall on its face and then take off, kinda like as if the accelerator pump was bad. after taking it apart checking everything and reinstalling, it still does the same thing. it ran great before I took the carb off and now it chugs before it goes. a buddy of mine cuffed his hands above the barrel and it would rev fine and when he didn’t it would hesitate. so could this be a mixture issue or choke issue? engine is 200ci and its a one barrel motorcraft. thanks
It is in the accel pump. The new pump may be good, but something is wrong. It is either misadjusted, or you left out parts on reassembly. With the engine off, shine a light into the carb and pull the throttle. If fuel doesn't squirt out into the venturi instantly, there is a problem. Edit: Yeah, as in the above post, you could have something lodged in the accel pump squirter circuit. Did you blow it out with compressed air?
I didn’t blow it out with compressed air, just generally cleaned it with gumout. so I should take it apart again and with compressed air blow thru what part of the carb? and were is this part cause i don’t really know most technical names for the innards of a carb. thanks and gas does come out when i pump it but it dosnt spray, just kinda spits
This info helps. It doesn't really "spray". It just squirts. When you say "spits", it makes it sound weak. This could be damaged pump diaphram/plunger seal, or clogged circuit. Now that we have determined that the pump is at least functional to some degree, does it squirt (spit) the instant the throttle is moved, or does the fuel come later? You need fuel to 'spit' instantly when the throttle is opened. If the throttle opens at all without some fuel 'spit', you will have a big hole in the acceleration of the car. If fuel doesn't come right away, adjust the pump linkage. If the spitting is not a steady stream, check the pump and circuit passage.
yea, its not a steady stream, so tomorrow I will try again. can I use a can of carb cleaner with the straw and place it into or onto the thing that’s supposed to shoot gas and possibly unclog it that way? and if that doesn’t work how do I adjust it? thanks
ok, I disassembled carb, cleaned everything again, blew thru every hole on that thing with b12 carb cleaner. everything is free of any clogs. checked new accelerator pump and put it together. car still hesitates when I hit the gas. accelerator pump squirts gas now a little better but im still not sure if its enough, how do I adjust the pump? and could my vacuum advance on the distributor cause this problem? thanks
I just messed with the choke and it runs great cold and as it warms up it starts to hesitate a little but not as bad. any ideas?
IS THE SQUIRT OF FUEL FROM THE PUMP INSTANT? Or does it release the fuel after the throttle has already moved a few degrees? Every carb is different. I am not familiar with that carb. Often the carb kit will have instructions... You need fuel applied as soon as the throttle blade opens to let air in. When your choke is on, the carb is drawing extra fuel from itself by force, so it will not hesitate easily. The fuel is needed to cover the air hole caused by moving the throttle, until the main metering system can activate. When the choke is adjusted rich, the main metering system is forced to provide fuel, meaning 'no air hole', but it also is running too rich that way. Waste of fuel and loss of power.
ok, I got it running great, it does squirt fuel instantly, I seriously think it was a choke issue cause I adjusted it more and now it doesn’t stumble at all, it doesn’t seem to run rich, I don’t see smoke or smell gas, it idles perfect (not high) and has plenty of power now without hesitation. the choke opens when warm, so its not constantly on. any other way to check if its running rich? I don’t think it is but what do I know. thanks for the help
Sounds like you worked it out... Drive it for a while, then pull a spark plug or two and make sure they are not fouled. Good work.
Air/fuel mixture Put a vacuum gauge on the crab and record idle reading when the car is warmed up and the choke is fully open. Adjust the air/fuel mixture screw until you get the highest reading. Back down the idle screw. TAKE IT FOR A TEST DRIVE, let us know how it runs. If you crab has 2 air/fuel screw just do it again for the second screw, highest reading, then back down the idle screw.
