rdobbs

have 81 chev trk 350 auto trans, recently put on new carb, now
when it cranks up and is put into gear it dies. you can pump the
accelerator softly and it wont die. after its driven several miles
the problem goes away. any help would be appreciated.
dobbs

broughy84

check timing, and idle speed.

__________________
Matthew Brough
1998 Chevrolet Venture -- 104,000 miles
1988 Chevrolet Silverado -- 156,000 miles
1996 Chevrolet Cheyenne -- 107,000 miles

jimss454

Did you get the problem solved?
Above member's suggestions are right on.
What brand of carb? Does the new carb have a choke? What type? (Electric, manual, or actuated by manifold heat). If you are not using a choke, it is nearly impossible to get a perfect idle setting for cold & hot operation - if you turn the idle up so it runs when cool, it will idle too fast when warm.
If you are using a choke, remember that when the engine is cold, you need to pump the gas ONE time before turning the key. This sets the choke. Also, there is a separate Fast Idle screw that may need to be bumped up. Idle speed when engine is cold should be slightly faster than normal hot idle.This screw rides against a stepped "cam", which rotates out of the way when the choke is not set. Also, if it is a factory GM Quadrajet carb, there is a round, black plastic housing on the passenger side. It contains the bi-metal spring that senses the temperature and adjusts the choke accordingly. Three tiny screws clamp this housing in place.You can loosen the screws just enough to allow rotation of this housing. There are tiny marks on the front of the housing, and it should have the words "Rich" & "Lean" on the side of the housing. Rotate it just a TINY bit, (1/16-1/8 inch) at a time, toward Rich, then tighten screws and re-test. Let us know what you find out, and best wishes! -Dan M.

rdobbs

the carb is a rochester 2barrel quad 2,choke is run
from manifold heat. timing is right, turned up idle
screw some, helped some but still not right. all
vaccum hoses been replaced. could it be that
the choke needs adjusting? thanks rdobbs

timberdoodle

sounds like it is just idling and killing the carb when you put it in gear. THe resounding nightmare of carbs. There is much tuning to do to get the carb going right. Best to get the engine up to running temp and tune the engine. The truck runs fine after you drive it for awhile because the engine heats up the engine compartment, making it a great environment for a carb to run in. Could be choke, idle speed, idle mixture.