High Rpm At Idle.....

[skylarker]

So the last few weeks I have been working on installing my new O.D.

Opened up a can of worms. Clutch pressure plate was cracked, pilot bushing was a project to remove,

rear axel seal blew out prior and ruined brake shoes, in the mean time I also thought my carb needed a rebuild since

it was last rebuilt about 7 1/2 years ago.

 

Besides the trans swap, relays, switches and  o.d. wireing harness and new clutch. Nothing else was changed or adjusted.

 

Now after the carb rebuild I cant get it to Idle right. air screw is all the way in idle speed screw is out not touching and it still idles high. 

 

52' Plymouth

218cid bone stock

Points ignition

Carter BB single barrel

 

Float set 5/64

 

Accelerator pump 3/8.

 

What am I overlooking or doing wrong?

 

[martybose]

Any chance that something in the throttle linkage shifted a bit so that it doesn't allow the carb to close all of the way?

 

Marty

[greg g]

does your linkage allow the throttle plate to close?  If not there are a couple places where the arms can be adjusted.  Try disconnecting the linkage from the carb, start the car then try your idle mixture screw.  If it makes a difference than you know your throttle butterfly was not closing completely, as the idle air screw will have no influence if the butterfly is not closed.

[skylarker]

I thought about that this morning.... so I lengthened the linkage a bit. But may be I can give it more length.

[skylarker]

Greg, I will look into that, I did something similar but instead just removed the carb return spring. but that only made the

linkage open up the butterfly.

[plymouthcranbrook]

Vacuum Leak?

[skylarker]

Vacuum Leak?

Where? I double checked and triple checked all screws and nuts.

I even did figure 8's on wet fine sand paper to all flat surfaces weed out ant warpage.

 I also tried with the vacuum line on and off, and plugged the vacuum fitting at the bottom.  

 

Should I try the thicker carb base gasket instead?

[skylarker]

Suspect found..... I disconnected the throttle linkage like suggested.(GregG) it still idles high.

 

so I swapped the old linkage piece (non Overdrive) for

the new overdrive kickdown linkage piece. Rpm come down to a regular speed.  

 

Any suggestions to correct this?