ROUGH IDLE

[Anonymous]

Hi Guys,
More questions, the engine and head code are c5de
I have replaced the dizzy with a single vacuum advance unit with no centrifugal advance, I have also replaced the Carburetor with a non spark valve unit, the dizzy is rebuilt, I rebuilt the Carburetor, the problem I have is the engine still seems to have a rough idle, I have checked timing and it is 6 degrees, I also checked the vacuum it reads about 17in, I have pulled the plug wires one at a time the rpm droop seems equal on all cyls,
seeing this whole thing was a basket case I wonder if the problem could be in the valve train, it has hydrulic lifters and adjustable rocker arms, I had to rebuild the shaft as it had galling , I know the rockers are fine and the crank pulley is marked correct I checked it with the piston at tdc with a wire rod, the lifters are quiet but I wonder if I have them too tight, what is the correct procedure for adjusting them, also if that is not my problem what else would give me a rough idle, I have used propane to check for vacuum leaks but there are none, it is not enough to shake but it is enough that it is annoying.
Thanks Fred

 

[addo]

Fred - you may have issues with something like cam wear, but it's not too common.

Remember to set the idle with a reasonable alternator load on the motor, and (if an auto) with the trans in drive.

To set the lifters:

Put the motor at TDC compression for #1. Back off the adjusters for #1 intake and exhaust until the pushrods have room to jiggle easily up and down when gripped between your fingertips. Leave several minutes in case they're gummy and stuck.

When you return, again grip the pushrod between fingertips and gently jiggle up and down while slowly tightening the adjuster nut. The moment you feel all free play has gone, add one full turn on the adjuster.

Turn the crank 1/3 revolution, and set the adjusters for #5. Then another third and set #3. Being a four stroke engine, it will of course take two complete revolutions of the crank for all settings to be confirmed.

Regards, Adam.

 

[james singleton]

Fred, I know that it has been talked about many times on this forum, but doesn't a single-vacuum distributor (like the Load-a-matic) go with a carburetor that does have a spark-control-valve!????? Jim