rough idle/acceraltion

Posted by Ken Bigham on May 11, 1997 at 20:33:41

I'm hoping someone out there has a suggestion to help me with a problem i'm having.
My engine has recently been rebuilt. 30 over all the ususal
balanced, adjustable tappet, hardened valve seats etc.
My problem is that I have been unable to get the motor to run
smoothly. It starts easily, but requires that the fuels mixture
be turned open 3-4 full turns. At that stage it will run and
accelerate well. Any less and the engine, bucks and will
not accelerate.
The timing is correct as far as I can see. I have tried 2
Zenith carbs and 1 x aftermarket carb which runs the best of the three. I've checked the fuel flow which is adequate
and have even blocked off the windshield wiper vacum.
The engine just seems to be running like it has a vacum leak.
The manifold was milled and there were no apparent cracks.
I've also retightened the manifold...all to no avail.
I really think it is carb or intake manifold related.
On the road the car runs o k,does not overheat etc...
but just will not run at idle. The air screw on the carb is currently 1/8 open. Opening the screw kills the motor.
I know that the engine is very tight..spec wise, and maybe this will improve after breakin...
I appreciate any help or advice.
Thanks in advance.
Ken

Follow Ups:
Re: rough idle/acceraltion Ken Bigham May 15, 1997 at 07:06:55(0)
Re: rough idle/acceraltion Ralph Holland May 13, 1997 at 15:53:43(0)
Re: rough idle/acceraltion doug Linden May 12, 1997 at 14:05:54(1)
Re: rough idle/acceraltion RBraswell May 12, 1997 at 18:31:10(0)
Re: rough idle/acceraltion Jim McPherson May 11, 1997 at 21:42:03(1)
Re: rough idle/acceraltion Bob Carabbio May 11, 1997 at 22:11:16(0)

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