Major RPM drop 79 chevy

[VileZambonie]

The port on the front of the carburetor on the driver side.

[Lt.Del]

see my pic i posted.  That's the stock place for a '79.

[xjames14x]

ok yes i see it, that is going to my vac advance while the passengers side vac is going down to my transmission modulator, in the picture i posted you can see them...my father says that its my carb so im probably going to try to rebuild or buy a new one

[bake74]

     In your picture, to the left of your blue star, there are 3 hoses, 1 big and 2 smaller ones.  1 of the smaller ones should be hooked to your vacuum advance on your distributor.  I have the same set up and that is where my vacuum advance is hooked up.

[bake74]

     I do not know if this is the same as you.  When I would drive mine and as long as I stayed barely into the gas pedal it ran fine, when I pushed into gas more than say 1 " my truck would "chug, chug" then level out.  
     I ended up replacing my pcv valve and corrected the problem.  In your picture, the big hose in between the 2 little ones should go to your pcv valve on one of your valve covers, mine is on my passenger side.
     The pcv valve has to do with crankcase vacuum, that helps control the vacuum advance on your distributor as I recall.

[VileZambonie]

ok yes i see it, that is going to my vac advance while the passengers side vac is going down to my transmission modulator, in the picture i posted you can see them...my father says that its my carb so im probably going to try to rebuild or buy a new one

You should have manifold vacuum going to your modulator not ported vacuum.

[Lt.Del]

yeah, what Vile said.  The manifold vacuum for the modulator is usually right behind the carb in the intake manifold. Near the distributor. It goes down to the transmission modulator.   

[xjames14x]

yeah, what Vile said.  The manifold vacuum for the modulator is usually right behind the carb in the intake manifold. Near the distributor. It goes down to the transmission modulator.   

ok im going to have to fix that then, this thing is just hillbillied together, im just trying to figure out stuff and knocking out things and narrowing them down, also talking to my father i need a new rotor for the distributer....going to go buy spark plug wires tomorrow and maybe even a new distributor cap, i appreciate all the help and i will keep you posted, you guys have been a lot of help
 

[xjames14x]

ok so let me get this straight here.....i should have one vacuum hose going from the modulator on my transmission to a port on the manifold (passengers side near distributor?)? And then i would need a vacuum hose from the vacuum advance to my carb that is on the drivers side port next to the idle adjuster?

also if anyone knows the ins and outs of an edelbrock 1405 carb that would be great too

[beastie_3]

you can download the tuning manual and rebuild manual for that carb on edelbrocks site.

[xjames14x]

     In your picture, to the left of your blue star, there are 3 hoses, 1 big and 2 smaller ones.  1 of the smaller ones should be hooked to your vacuum advance on your distributor.  I have the same set up and that is where my vacuum advance is hooked up.

yes the smaller hose on the drivers side of the carb is going to my vac advance

[xjames14x]

you can download the tuning manual and rebuild manual for that carb on edelbrocks site.

ok thank you, about to go to the parts store to buy a vacuum plug for the manifold, so i can hookup the modulator hose to that instead of it running to the carb