engine runs , I got the tach hooked up and above 2000rpms it runs just fine , but as soon as I let of the throttle
the car dies...

why ?

how can I fix this ?

It's a 355 , holley carb (belive it is 650 double pumper)

I'm not totally sure if I have vaccuum hoses routed correctly and stuff... would that make a difference ?

Brad Mac got the engine running and I Don't know if maybe the timign is too advanced and needs to be taken back
a few degrees

wires are kinda old and cracked/burned up , so I'll replace those soon

spark plugs looked ok but I'll replace them too (I am not having misfires , so I don't think these two are the issue).

how do I adjust the idle on a holley carb ?

will that help ?

what else should I try ?

engine runs fine above 2000rpms, just dies immediately after I let off the gas...

 

First thing to check for is vacuum leaks. Look around carefuly for vvacuum ports on either the carb or the intake that aren't hooked up or plugged. The first place I'd suggest looking is in the back of the carb, at the center of the throttle plate; there may be a BIG tap for power brakes there, which would be a massive leak if it doesn't have a plug.

Idle speed is usually a little screw on the driver's side, on the throttle plate, such that the throttle lever comes to rest against it. Don't go messing with it until you've made sure the car is assembled correctly. It's kind of pointless to try to adjust something that isn't put together right.

Same for the timing: too much advance won't make it do that. Not enough, maybe; but not too much. Leave it alone until you're sure everything is put together right, that way you don't adjust yourself into the ozone, have a car that still doesn't run right and is even harder to troubleshoot, then you have to undo all the things you did to try to work around the real problem. Playing with the adjustments is just a good way of creating extra work for yourself.

------------------
"So many Mustangs, so little time..."
ICON Motorsports

 

I don't think I have any vacuum leaks, I just spent a good hour trying to trace everything down and I dont' see anything wrong with it (not that I have a clue what I'm doing , lol , but I'm trying )