Secondary's not opening. Z24

[heywier427]

I remember this truck used to have balls.  It has been temporarily clipped...

 

Secondary's not opening verified by putting grease on the diaphragm rod.  It did not suck up into the actuator.  

 

Rod moves freely when pushed up manually/butterfly opens/fuel is delivered.  

 

Butterfly's open freely when pushed open through the carb intake/throttle body.  Hooked up a hood release cable to manually operate the actuator at speed.

 

It worked.  Truck accelerated.

 

Truck runs great.  Idles well.  All vacuum lines are good.  Most have been changed.

 

 

 

Can this be fixed easily.  Is there a certain venturi opening I can clean/blow into.

 

I blew into all the ones I could find with no change.

 

Taking apart the actuator pot looks like a pain.

 

If no easy solution is to be had, its finally going to get the 38/38 and cam.

 

Thanks for any suggestions.

 

 

Edit: Not switching it over to mechanical secondary, as that doesnt seem like it can be done on the engine.  If its coming off, its staying off.

[datzenmike]

The diaphragm may have a leak. Three screws 
 


The vacuum is supplied by both venturies internally to the diaphragm. Maybe mounting gasket on the diaphragm not sealing?

[heywier427]

The problem I see, even just to check the diaphragm, is one of the 3 top screws is blocked by another actuator. 

 

Looks like you have to remove the secondary actuator, and then remove the cap.

 

And it looks like you have to pull the carb to take off the secondary actuator...]

 

Does that sound correct?

[heywier427]

Meh, I went ahead and put the weber on.  

 

Big improvement, but Im pretty sure there is more.

 

I havent adjusted the valves in 150,xxx or tightened the head studs... :wacko:

 

 

20170708_234914[1] by thomas telesco, on Flickr

 

 

 

Maybe tomorrow :)  Gotta get to that leaky gas tank at some point too!

[Cheetosrdabest]

The problem I see, even just to check the diaphragm, is one of the 3 top screws is blocked by another actuator. 

 

Looks like you have to remove the secondary actuator, and then remove the cap.

 

And it looks like you have to pull the carb to take off the secondary actuator...]

 

Does that sound correct?

Sounds about right :(. Mine was doing the same thing so I just pulled the carb and rebuilt it while I had it off...wasn't too bad, just a lot of little parts...take a bunch of pictures for reference on how the little springs and things go back together for sure if you go for it ! After the carb rebuild, it runs (and starts) like it did when it was a baby ( I've had mine since it was only 1 year old back in '85)