1966 327 350 problem

[Alton J.]

hi

I just had my original type holley carb rebuilt . When I start the car cold the idle never changes . The divorced choke does work . It pushes the linkage up when hot then goes down when cold but the idle speed never changes .

[Stuart F.]

Re: 1966 327 350 problem

The high idle linkage is not engaging properly. Not knowing the details of your specific carb, I can't say how to adjust it, but it is either a screw or a tab that fits into or rides on a cam surface. Check your service manuaL.

Stu Fox

[Alton J.]

Re: 1966 327 350 problem

Thank you Stu

I will check that linkage . The carb should be like new though ? Did the carburetor rebuilders mis this ?

[Stuart F.]

Re: 1966 327 350 problem

If there is a specific adjustment that can be made on the bench, such as a clearance dimension which can be done with say bending a linkage rod, they will do it. If it is a tab that fits within a cam, they can only assume it was close before and the final adjustment needs to be done on the engine during a warm up cycle. Same holds true with any screw adjustment - they can do a "dry" set (temporary) adjustment and the final needs to be done on the engine. Some rebuilders say they can/do a test on a running engine, but not all engines or conditions are the same.

Stu Fox

[Alton J.]

Re: 1966 327 350 problem

Stu , Its a Holley 4bbl. # 3367

Thanks again .

[Edward J.]

Re: 1966 327 350 problem

Alton, sounds like the Fast idle cam is hung up. should be a link on the choke side that lifts the cam that has steps to raise the idle speed, It may require a close look at the operation, Just follow the linkage from choke butterfly, pretty simple operation.

[Russ S.]

Re: 1966 327 350 problem

It is a tab that may need to be bent closer to the plastic high idle cam.

[Duke W.]

Re: 1966 327 350 problem

There's no need to guess. The applicable service manual ('66 CSM in this case) will contain all the various linkage adjustments, and these checks and changes, if necessary, should be done on the bench after the carb is assembled following a normal overhaul.

Duke

[Stuart F.]

Re: 1966 327 350 problem

I stand by my statement with regards the high idle and, for that matter, the choke adjustment being items you can do with the carb on the engine. If you have the divorced choke which, other than the link, will stay with your engine. The service manual will describe the high idle adjustment on your running engine; Believe they say to warm the engine fully, then manually position the fast idle cam to the high step, then setting (bending) a tab or turning an adjustment screw to attain the specified engine speed using a reference tachometer - something like 1500 RPM.

Your best bet is to refer to the service manual, if you have one, or get one specially if you intend to keep the car for awhile.

Stu Fox

[Duke W.]

Re: 1966 327 350 problem

Yes, all adjustments can be done with the carb installed, but the OP stated that the carb was recently overhauled, and part of the overhaul procedure is checking certain items and adjusting them as necessary to meet spec, and this should have been done by whoever overhauled the carb, but maybe it wasn't.

Depending on the carb, final adjustments such as fast idle and curb idle and idle mixture must be done on the car.

As has been said, it's simply a matter of checking all the adjustments that are mentioned in the applicable CSM, making sure they are in spec, and checking for missing parts.

Duke

[Alton J.]

Re: 1966 327 350 problem

I really appreciate the help guys . Thank you very much.

I spoke to the carburetor shop who rebuilt it and he said that it was an adjustment screw on the passengers side at the base/ front of the carburetor .

I could not find the screw he was referring to . I did not see any adjustment screws at the front base . I will just have a good mechanic adjust it ? . It doesn't sound like a big deal .

[Russ S.]

Re: 1966 327 350 problem

Of course you couldn't find the screw. It doesn't exist!

I really appreciate the help guys . Thank you very much.I spoke to the carburetor shop who rebuilt it and he said that it was an adjustment screw on the passengers side at the base/ front of the carburetor .I could not find the screw he was referring to . I did not see any adjustment screws at the front base . I will just have a good mechanic adjust it ? . It doesn't sound like a big deal .

[John H.]

Re: 1966 327 350 problem

I spoke to the carburetor shop who rebuilt it and he said that it was an adjustment screw on the passengers side at the base/ front of the carburetor .

I could not find the screw he was referring to . I did not see any adjustment screws at the front base . I will just have a good mechanic adjust it ? . It doesn't sound like a big deal .

There is no such screw on a 3367. Click on the link below - it will take you to an article I wrote in "Corvette Enthusiast" magazine on precisely the issue you describe.

http://www.lbfun.com/warehouse/tech_info/fuel%20&%20intake/Fast_Idle_Tech.pdf