surging

[89CUSTOM]

my 4.9 in my 89 surges when idling, from about 1000 rpm to 500 rpm back and forth untill it dips so low it dies, also since I have had this problem, when I shift (5 speed) and depress my clutch from 1st to second, it revs to 2 grand and I have to wait untill it comes down to shift, is this connected?? thanks love my truck!!

 

[rousch99]

id check for vacum leaks first my 96 5.0 was surging on hills it was nothing but a vacum leak