Outer Limits 4x4 Board

i have a 1991 sierra soft top.
my brake vacuum booster must be leaking i plugged up the hose that leads to the carby, just above the erg valve, and surprise surprise, the car idles like a dream. gonna exchange mine for a recon one.

i also found the vacuume advance controller (the diaphram on the distributor) was leaking and not advancing the timing with increased revs. but that didnt affect the idle tho.

hope this helps someone out there. cause i know its frustrating trying to fix a idle problem.

josh9465 , great post have had sim problem a bit of tlc and it was going great....
Did you see the paint marks on all the adj screws too from oem????

im not sure what paint marks ur talking about.

Speaking of annoying carb issues....

had one with mine over the last week, no second throat opening... operated fine by manual linkage fiddling under the bonnet, so i figured vacuum... was right to, crap from a jammed pcv had been building up in the carb and blocked the pick up point.

follow up on tuesday morning... revving the wringer out of it with me not in the car, 3.5k on the dial... why?.. cause with all my manual fiddling the accelerator knob had slipped sideways and hooked the cable over the guide at the carby... thanks dave for making me feel silly!

Spock