obtaining correct idle speed

[flattiefreak]

ive been working on this 1958 plymouth for a while and am still having little problems with the 230. it runs great,but i have to close the choke(no matter what the temp is outside) to get it started. it does not help if i prime the carb with gas either. then, i have to open the choke because my scission choke doesnt work. once this process is over it starts up fine. i got the timing set good and the the idle speed is set way to high. i try to adjust the idle speed screw but it makes no difference, the speed only increases . so the idle speed screw is almost all the way out. what is left to do? im thinking about saving up a little money and buying a new 2 bbl carb with electric choke.

[Young Ed]

What kind of carb do you have currently? Something is way wrong or broken if the idle screw doesn't make a difference. You might have a cracked seat for the needle

[flattiefreak]

i have the carter b and b carb. its been rebuilt twice and doesnt seem to work any better.

[1949P17BC]

When you rebuilt it did you make sure BOTH ball bearings where free

[flattiefreak]

i didnt rebuild it myself. i think im just going to find a n carb.

[Niel Hoback]

It sounds like you have a vaccuum leak there. If your idle speed screw is backed all the way out and you still have a fast idle, air is getting in somewhere. That would also account for the need of a choke at any temp.

[greg g]

Or it could be the linkage for the fast idle cam is not releasing properly, might be because your choke isn't working properly. Are you sure it is a B and B? The later engines starting in 53/4 used the shorter BBR or BBS can;t remember which) thaat accomodated the lower hood lines of the later cars. They are shorter then the earlier carbs and the linkage for the accelorator pm is external.

The fast idel cam is a little deal that is like a spiral ramp around the throttle pin that the idle screw rests on while the choke is engaged. If it doesn't releas the screw will not make much differece in the idle speed.

[rolliejoe]

is you motor in good shape?

[spartanbilly]

Make certain the throttle plate is completely closed in the carburetor bore and is secure on the throttle shaft. It could be binding in the bore if loose. Should this be the case the suction past the plate will cause the idle circuit to become ineffective and fuel will then be sucked out of the "cruise" circuit of the carburetor giving you a high uncontrollable idle speed. Just a possibility, I experienced this on at least one occasion.

[flattiefreak]

i fnally got the idle to slow with the carb. i also think i got the choke working properly.

[old woolie]

How?

[flattiefreak]

all i did today was take the screw out and then start turning it back in and it worked and that somehow seemed to make the choke work

[old woolie]

Well that is pretty vague.

[Tom Skinner]

Dear Flattie,

Set your timing correctly then:

Borrow a Vacuum Gauge.

You warm up your engine, connect your Vacuum Gauge to plug on Intake Manifold, then turn your Idle Screw (In or Out) until you obtain your highest reading.

This is done after your timing is set correctly.

Thats how to obtain optimal performance out of our Flat Head Engines.

Tom

[Tom Skinner]

I use an Tach and Dwell to obtain Rpms.

usually around 450 - 475 at Idle (warm for a Fluid Drive).

Tools use em!!!!!!

They are useful instuments that work.

[PatS....]

Well that is pretty vague.

flattiefreak is only 17 and very new to cars in general...this is all a learning experience for him so a bit of patience may be in order

[flattiefreak]

i got the timing set correctly and the carbs working good now. so im happy. and yes this is all a learning experience for me.

[Tom Skinner]

Dear Flattie,

Good work!

Tom