Going back to an Aisin

[Trollhole]

So I have decided to go from the weber 38 to a 78 Aisin. Have a few questions.
Cruiser has a single fuel line from tank to fuel pump and from the fuel pump to a section of hose that was connected to the carb. No smog what so ever on this engine.

What year model fuel pump had the fuel return from the carb to the pump?

I figured I would just buy a new fuel pump and fuel lines and be done with the fuel side.

Also I've got the vac line from the distributor. I know where that will go on the carb. But what should I do with all the other ports? SHould I just cap them on the carb?

My goal is to get a good running carb and retain as good of gas milage I can get.

 

[Poser]

What year model fuel pump had the fuel return from the carb to the pump?

I figured I would just buy a new fuel pump and fuel lines and be done with the fuel side.

Also I've got the vac line from the distributor. I know where that will go on the carb. But what should I do with all the other ports? SHould I just cap the on the carb?

My goal is to get a good running carb and retain as good of gas milage I can get.

1979 and later....Make sure that you get the phenolic spacer and gasket assembly from Toyota since the later pump requires the spacer because of the longer arm mechanism on the pump to the camshaft.

But what should I do with all the other ports? SHould I just cap the on the carb?

Cap them.



Good luck!


-Steve

 

[Degnol]

I thought the secondary was vacuum operated on a '78 carb? What will actuate that?
Just trying to learn something here.

Ed

 

[Poser]

Should have a hose on it going to the diaphragm from the carb, iirc....was not assuming that it was removed and missing/not attached...

 

[Pin_Head]

'75 - '78 also had a fuel return line, but not at the pump.

The secondary is operated by vacuum from inside the carb. No hose needed.

 

[Degnol]

The secondary is operated by vacuum from inside the carb. No hose needed.

See, this is what I was trying to learn. I thought the vacuum secondary had to route through a VSV or something else external to the carb. So, I could run a '78 carb on my '772F with a 2F intake and not use any smog stuff? My cruiser is a '66 and has no smog of any kind. Only vacuum is to the diz via a ported vacuum '74 Cali throttle base.
Man....I learn something every day-on-Mud


Ed

Thanks Charlie.

"Should have a hose on it going to the diaphragm from the carb, iirc....was not assuming that it was removed and missing/not attached..."


And Poser....of course.

 

[Pin_Head]

'78 carb isn't that different from a 77, so it should work fine. There are three ported vacuum lines on a 78 that sample vacuum at different levels of the primary bore. The two closest to the idle mix screw are the closest to the throttle plate, so pick one of those and cap the other two. The VSV and smog computer is supposed to run the throttle positioner and power valve. You can remove the TP and run a hose from the power valve port (#8 line on the front of the top cover) to manifold vacuum, which will keep it closed, but I am not sure that it will ever see vacuum low enough to open. There is also a bowl vent line to the charcoal canister that will need to be plugged if you con't have the can. You also need to plug the EGR port on the drivers side of the carb.

 

[Trollhole]

Back to learn my ABC's

A- capped. There is no large outer vent hose on a 76 canister.
B- capped. EGR inlet to carb
C- choke breaker. connect to vacuum fitting on intake manifold in front of carb. Remove TP linkage.
D- remove.
E- ICS- connect to stock carb wire.
F- HIC. connect to vac nipple on PCV fitting in side of intake.
G- distributor vacuum advance, if so equipped.
H- cap
I- cap
J- fuel feed
K- fuel return. Plug if using 79-newer pump.

 

[Poser]

B was attached to the EGR system, iirc....but I do not see why you could not use it for the PCV system.

 

[Trollhole]

Okay question.

Where would the normal PVC line go?

 

[Degnol]

Usually to the center of the intake manifold.

 

[Poser]

As Ed posted, to the center, driver side of the intake below the carb...and is routed to the rear of the engine. There is a threaded fitting into the side of the intake on earlier 2F's that is specifically for the PCV system. On later versions, there is a two stud plate affair that has a hose barb welded to it for the PCV hose connection and a pipe out the other side that attaches to the EGR valve...

 

[bustanutley]

Thanks for posting this Troll, I have been pondering giving the 78or79 carb I have laying around a try, but wasn’t sure what I needed to hook up. I have an F so I’m not sure if that would yield any issues as far as sizing goes. My webber runs well, but I think I may be able to get a little move angle out of a stock setup.

Carry on with the info

 

[Trollhole]

So besides the egr pcv issue nobody sees a problem with my ABC's and what to capp and what not to?

 

[FJ40Jim]

Back to learn my ABC's
A Bowl vent Can be capped? (should go to charcoal canister)
B EGR port but can be used for PCV (need this)
C TP (can be capped)
D Carb Temp (doesn't need to be hooked up)
E Idle solenoid (needs to be hooked up to switched ignition)
F ???
G EGR port (can be capped)
H TP (can be capped)
I Advancer port (go to distributor)
J fuel out?
K fuel in

I'm gonna assume we're talking about installing this 1978 carb on a desmogged but otherwise stock 1976 2F.

A- capped. There is no large outer vent hose on a 76 canister.
B- capped. EGR inlet to carb
C- choke breaker. connect to vacuum fitting on intake manifold in front of carb. Remove TP linkage.
D- remove.
E- ICS- connect to stock carb wire.
F- HIC. connect to vac nipple on PCV fitting in side of intake.
G- distributor vacuum advance, if so equipped.
H- cap
I- cap
J- fuel feed
K- fuel return. Plug if using 79-newer pump.

And lastly, the choke idle speed screw is turned in way too far.

 

[FJ40Jim]

B was attached to the EGR system, iirc....but I do not see why you could not use it for the PCV system.

Can't be used because it is not manifold vacuum.

PCV has to be connected somewhere below the throttles.

 

[Trollhole]

updated You are the man Jim. Thanks for the help.

 

[Trollhole]

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


TP linkage being 1 or 2?

 

[baldboy]

No technical help here-just curious....

What made you want the Aisan carb over the Weber 38?


Thanks.

 

[Trollhole]

angle of aproach. And the fact that I know how to rebuild an Asin.