mazdatweaker
+1y
It can be done with the carburetor on the truck. It's a lot easier to do if you remove the carburetor and do it on a bench The cover (air horn) has to come off to remove the pump.
There is a couple of things that need to be watched.
Removing the choke heater wire from the back of the alternator, and whatever it might be secured to, under the manifold where it routes to the carb.
The choke linkage has a bitty e-clip that will make things really aggravating if you lose it. There is another e-clip on the pump linkage that has to be attended to as well.
The mixture control solenoid has an 0-ring on the bottom that will need to be replaced, because likely it will not be re-usable. The solenoid is attached to the cover, and will pull out of the well it is installed into when you pull the cover. The cover will probably be stuck to the body of the carb because of the 0-ring, so you have to be careful when you get all the screws out of the lid, on how you pry the parts apart.
There is an idle-up solenoid linkage if you have AC, bolted to the manifold that slips into a hole on the carb near the bottom.
If you take the carburetor off, it is a good time to flush out the bowl with cleaner. Also, now would be the correct time to remove the roll pin blocking the idle mixture screw if it hasn't already been done. If you don't know how to do that, leave it alone, because the wrong kind of force can crack and ruin your carb.
After reading all of this, why do you think you need an accelerator pump? How did you test it to see if it is bad?