[Carousel72TRed]

I have a Holley 750 carb vacuum secondaries on my GTO with an aftermarket 17" air cleaner. I have a ram air air cleaner and when I put the ram air air cleaner and filter on it the idle on the car goes up substantially. With the aftermarket air cleaner is a spacer that sits on top of the carb prior to putting the aftermarket air cleaner on. I take the spacer off prior to putting the ram air air cleaner on. It does not look like the ram air bottom pan is hitting the throttle causing it to go up. Has anybody encountered this and should I try to leave the spacer on prior to installing the ram air air cleaner.

Carousel72TRed

[Joe's Garage]

Does the Ram Air air cleaner sit down flat on the carb without the spacer, or is it tilted just a tiny bit?

We had one, many years ago, that the air cleaner just barely touched the top of the Holley throttle arm, just enough to raise the idle about 1000rpms.

We had to tap a small dent in the air cleaner base to clear the throttle arm. Then it was fine.

Try setting the Ram Air air cleaner in place and then starting the engine with the hood open. Apply a little pressure in various places on the air cleaner base and see if the idle changes. If it does change, the air cleaner is pushing on some part of the carburetor linkage and making the idle go up.

If you then install the spacer and the Ram Air air cleaner and put pressure on it in various places or even snug it down and the idle doesn't change, you've confirmed that the air cleaner is touching somewhere.

Just don't close the hood without verifying that there is clearance between the air cleaner and the hood plate.

Good luck!

["QUICK-SILVER"]

Does that Holley have a manual choke lever that the breather base could be pushing on?

Clay

[Carousel72TRed]

Originally Posted by "QUICK-SILVER"

Does that Holley have a manual choke lever that the breather base could be pushing on?

Clay

The Holley on my car is an electric choke. It has 2 wires going connections on the choke housing cover.
Carousel72TRed

[Carousel72TRed]

[QUOTE="QUICK-SILVER";6290473]Does that Holley have a manual choke lever that the breather base could be pushing on?

No it has an electric choke. There are 2 wires going to the choke housing cover.

Carousel72TRed

[dataway]

The OEM air cleaners bases are pretty efficient .... could be the RA base is just working a lot better than the aftermarket base to smooth air flow into the carb at idle. Could easily lead to a change in idle rpm if the idle mixture settings were borderline in some way. If you can reach in and try to push the throttle to the stop (gently) with the RA base installed and the rpm stays up ... probably just running better.

[Carousel72TRed]

Originally Posted by Joe's Garage

Does the Ram Air air cleaner sit down flat on the carb without the spacer, or is it tilted just a tiny bit?

We had one, many years ago, that the air cleaner just barely touched the top of the Holley throttle arm, just enough to raise the idle about 1000rpms.

We had to tap a small dent in the air cleaner base to clear the throttle arm. Then it was fine.

Try setting the Ram Air air cleaner in place and then starting the engine with the hood open. Apply a little pressure in various places on the air cleaner base and see if the idle changes. If it does change, the air cleaner is pushing on some part of the carburetor linkage and making the idle go up.

If you then install the spacer and the Ram Air air cleaner and put pressure on it in various places or even snug it down and the idle doesn't change, you've confirmed that the air cleaner is touching somewhere.

Just don't close the hood without verifying that there is clearance between the air cleaner and the hood plate.

Good luck!

Thank You Joe's Garage. You have described exactly what probably is going on with my Ram Air Air Cleaner on my Holley carb. It does tilt a little bit. I will verify that with the procedure you have outlined. Unfortunately I have been using the aftermarket air cleaner with the spacer and I do have some dings around on the hood plate lip where it has touched. It is not too bad though.

Carousel72TRed