Fast idle

[Jim Yergin]

Looking for suggestions as to why I can't get my idle speed down below 1500 rpms. I have a P12 with a newly rebuilt 230 and a George Asche rebuilt carb. Runs great except for the fast idle. The idle adjustment screw is backed all the way off, the throttle linkage return spring is in place and in good condition, and the throttle arm on the carb appears to be all the way back at rest. The timing is about 6' advanced. I could not find any vacuum leaks using both carb cleaner and unlit propane at the induction points. Any ideas?

Jim Yergin

[james curl]

Check your vacuum advance to see if is good, it should hold vacuum if you pull the line from the carb and suck on it. If the vacuum advance is bad Terrell Machine in DeLeon,Tx can rebuild it.

[Don Coatney]

Jim;

Back your timing way off. I think the book calls for 2 degrees after TDC or something like that for a 230 CI Dodge engine. My book is at home so I cant check it out.

[claybill]

..throttle arm on the carb APPEARS to be at rest.......well,.... take your finger and press it all the way back when it is at idle..it usually can go another 1/8in more....then lengthen it that much to ensure it is ttotally back.

bill

[Jerry Roberts]

If there is any question of perhaps your throttle linkage holding the throttle partially open , disconnect the linkage and see if if will idle down .

[james curl]

Only if you use a spring to hold the throttle plate shut, if you disconnect the throttle linkage and start the engine the throttle plate will move to the trail position in the air stream or wide open before you can get out of the car to close it by hand.

[Plymouthy Adams]

has your carb plate been disassembled at any time..if so was the throttle plate mounted onto the shaft 180 or maybe tightened down without it being totally concentric to the bore? If this plate will not shut off completely the idle will become totally out of your control

[Jim Yergin]

has your carb plate been disassembled at any time..if so was the throttle plate mounted onto the shaft 180 or maybe tightened down without it being totally concentric to the bore? If this plate will not shut off completely the idle will become totally out of your control

Tim,

Not that I know of. It was rebuilt by George Asche and installed as it came out of the box.

Check your vacuum advance to see if is good, it should hold vacuum if you pull the line from the carb and suck on it. If the vacuum advance is bad Terrell Machine in DeLeon,Tx can rebuild it.

James,

If it is not holding vacuum, how would that increase idle speed?

Jim;

Back your timing way off. I think the book calls for 2 degrees after TDC or something like that for a 230 CI Dodge engine. My book is at home so I cant check it out.

Don,

From reading past posts it was my understanding that the timing should be advanced up to the point of no pinging. I have no pinging.

..throttle arm on the carb APPEARS to be at rest.......well,.... take your finger and press it all the way back when it is at idle..it usually can go another 1/8in more....then lengthen it that much to ensure it is ttotally back.

bill

Bill,

Sorry that I wasn't clearer. I have done just that and there is no more movement, it is totally back.

Thank you all for your ideas.

Jim Yergin

[james curl]

If the vacuum advance will not hold vacuum when sucked on the diaphram is torn and is allowing the engine to suck air in through the distrubitor.

[Plymouthy Adams]

Jim..I had to ask that question as it has total control over your idle..now the next question..did this just start or is this the first time to run the engine? Anyway if this is a first time..I would not overlook unbolting the carb to verify the plate position if nothing else seems to help..

[Don Coatney]

Don,

From reading past posts it was my understanding that the timing should be advanced up to the point of no pinging. I have no pinging.

Jim;

Try the timing adjustment. If it fails to work I will not charge you. I think I missed my calling. I should have been a lawyer:D

[claybill]

either a lawyer or a cab driver!!

bill

[Don Coatney]

either a lawyer or a cab driver!!

bill

Actually I was a school bus driver for a while. Does that qualify:confused:

[Plymouthy Adams]

School bus driver that spent the night at a Holiday Inn...maybe!

[Don Coatney]

School bus driver that spent the night at a Holiday Inn...maybe!

I was just a trainee in the night at the Holiday Inn:rolleyes:

[greg g]

Lots of comments here and I didn't read them all, what is the condition of the fast Idle linkage and its cam. Mine was sticking out and even though the linkage for the fast idle was relaxed, the cam was hanging up at the outer part of the pivot, there by holding the fast idle open regardless of the position of the linkage.

[Jim Yergin]

I finally got around to dealing with the fast idle. I retarded the timing as suggested by Don Coatney. That did not do it. Yesterday I replaced the vaccuum advance and now the car idles just fine. Thank you James Curl. When I removed the fitting on the old vaccuum advance to transfer it to the new one, I found gasoline pooled up inside. What does that indicate?

Jim Yergin