Re: I need help on 1987 366 truck engine

Posted by Bob on March 31, 2006 at 16:01:21 from (64.21.249.40):

In Reply to: I need help on 1987 366 truck engine posted by 69zfarmer on March 31, 2006 at 15:13:25:

The Holley "expert" was about as full of BS as can be when he attributed the failure or ONE of the idle adjust screws to affect idle as being due to a carb with a cfm rating that is too small!!!

I would suspect the carburetor, but, since the problem apparently remained the same when the carburetor was changed, it points to other things.

You may have a cracked intake manifold, bad intake manifold gasket, burned valve, or even a flat camshaft that is affecting one cylinder. Or, even a vacuum leak in an accessory that connects to one side of the manifold.

Each 1/2 of the carburetor feeds 1 "plane" of the intake manifold, which feeds 1/2 of the cylinders, every other one in firing order.

If there is a leak or a bad valve, it will be impossible to set the idle on one side of the carb, and all 4 cylinders fed by that 1/2 will be affected.

Check the compression of all 8 cylinders, and also, connect up a vacuum gauge, to see if the vacuum is steady, but low, indicating a leak, or pulsates, indicating a burned valve or other valve trouble.

Replies:

Add a Reply Name: E-Mail: Subject: Comments: Optional Link URL: Link Title: Optional Image URL: Email Notification: If you check this box, email will be sent to you whenever someone replies to this message. Your email address must be entered above to receive notification. This notification will be cancelled automatically after 2 weeks.

TRACTOR PARTS	TRACTOR MANUALS

We sell tractor parts!  We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today. [ About Us ]