Going back to an Aisin

[FJ40Jim]

No technical help here-just curious....
What made you want the Aisan carb over the Weber 38?

Because the Aisan 38/40 is bigger than the weber 38/38.

Bigger is always better.
Too big is about right.

 

[FJ40Jim]

C- choke breaker. connect to vacuum fitting on intake manifold in front of carb. Remove TP linkage.

TP linkage being 1 or 2?

TP is #2. The adjust screw is already completely removed from the end of the bellcrank, thereby disabling the TP function. You're golden.

 

[Trollhole]

One more question. Do I have to use the 79 and above fuel pump. Could I just plug the fuel return line on the carb and run my 76 fuel pump to it? Or is there something special about the 79 fuel pump?

If so what do I do with the other inlet on the fuel pump?

 

[FJ40Jim]

79-later fuel pump has one inlet, one pressure outlet to carb and one low pressure return from pump to tank.

73-78 has one inlet to pump, one pressure outlet to carb, one low pressure return from carb to tank.

If running a 78 carb on a 76 truck, just use the stock fuel line routing. It's the best setup.

 

[Pin_Head]

You can use any fuel pump you want.

F is the power valve and it needs manifold vacuum to close so it doesn't run rich all the time.

 

[Trollhole]

So no matter what I'm going to need a fuel return back to the tank.

Thats what I needed to know since my setup right now doesn't have fuel return. Not that I couldn't add it back.

 

[Pin_Head]

You don't need a fuel return line, but the '78 carb has a fitting for one. If you don't plug this return line you will have a massive fuel leak.

 

[Trollhole]

lol.