High Idle Cold Engine = How to set

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rnd5553
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High Idle Cold Engine = How to set

Unread post by rnd5553 » Sun May 14, 2017 7:26 am

I don't have a fast idle on my cold 66 110HP Manual engine. The carbs were recently removed to facilitate an engine swap. On back the "new" engine it and idles great when warm, but I have no High Idle when cold.

My question is, if the linkage is properly adjusted per the shop manual, shouldn't I be able to "mash" the accelerator once or twice to get the fast idle cam to "set" on my 66" 110 engine.

Per figure 12 (Eng.Tune Up 6-8) in the shop manual, isn't this what I should see with a cold engine after hitting the accelerator pedal couple of times, the throttle lever being set on the highest or second highest step?

Thanks for feedback.

66vairguy
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Re: High Idle Cold Engine = How to set

Unread post by 66vairguy » Sun May 14, 2017 8:43 am

The fast idle on first start up is typicall if the carbs are set up per the "book". Usually the idle will come down in a minute when you "mash" the gas pedal. No fast idle on start up could mean the choke thermal coils on the heads are not working or the linkage is missing and/or not adjusted.

There are a number of choke fast idle adjustments. You can adjust the links (they screw together) from the head coil to the carburetor and there is the linkage on the carburetor. If your carburetors worked O.K. before then the head choke coils and links to the carburetor on the replacement engine would be the first place to check.

Some don' t like the fast idle on startup and adjust the linkage for a slower idle speed on startup.

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bbodie52
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Re: High Idle Cold Engine = How to set

Unread post by bbodie52 » Sun May 14, 2017 8:55 am

Carburetor adjustment procedures — including choke mechanism adjustments — begin on the 17th page of the attached manual: DELCO ROCHESTER - Models H, HV Carburetor Service Manual.

I have also included applicable sections of the 1965 Chassis Shop Manual.
Attachments
DELCO ROCHESTER - Models H, HV Carburetor Service Manual.pdf
DELCO ROCHESTER - Models H, HV Carburetor Service Manual
(1.79 MiB) Downloaded 10 times
1965 Corvair Chassis Shop Manual - SECTION 6 - ENGINE TUNE-UP.pdf
1965 Corvair Chassis Shop Manual - SECTION 6 - ENGINE TUNE-UP
(2.92 MiB) Downloaded 2 times
1965 Corvair Chassis Shop Manual - SECTION 6M - ENGINE FUEL.pdf
1965 Corvair Chassis Shop Manual - SECTION 6M - ENGINE FUEL
(8.87 MiB) Downloaded 4 times
Brad Bodie
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rnd5553
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Re: High Idle Cold Engine = How to set

Unread post by rnd5553 » Sun May 14, 2017 9:16 am

head choke coils ----how do you remove these coils?

66vairguy
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Re: High Idle Cold Engine = How to set

Unread post by 66vairguy » Sun May 14, 2017 12:43 pm

rnd5553 wrote:
Sun May 14, 2017 9:16 am
head choke coils ----how do you remove these coils?
First make sure they are an issue. When the engine is cold the coil(s) should push the link up all the way. If you can pull up the link so it stops at the coil bracket then the coil has failed. When the link is pushed down a little it comes back up to the bracket stop on a cold engine. THERE SHOULD BE NO BINDING - often folks bend up these links so they bind in the head pass through hole.

To replace the coil(s), and lower link, you have to remove the lower shrouds and you'll find a stud that holds the coil(s) in the head. DO NOT SHEAR IT OFF. You have to use a small chisel and gently turn it out like a screw - in fact the stud has spirals so it must turn out during removal. Sometimes putting pressure on the coil bracket helps get the stud moving - BE CAREFUL.

Clark's sells new coils and studs - make sure you get the correct coil - there were two different types and I know Clark's catalog for the links from the choke coil to carburetor had those parts mixed up at one time. I told them, but they had to wait for an update to fix - not sure if it was fixed yet.

The other forum may have pics or a video on removing the coils.

NOTE - AFAIK - the new lower link can ONLY be installed when the choke is OFF the head (LM cars) - and don't put the link in backwards.

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bbodie52
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Re: High Idle Cold Engine = How to set

Unread post by bbodie52 » Sun May 14, 2017 1:17 pm

azdave wrote:
morgan95 wrote:The choke coil screws into the choke rod and the choke rod attaches to the car?

And if I'm not mistaken one end of the choke coil is threaded for the choke rod to screw into?

Did I get those two correct?
The choke coil has a straight rod attached that extends up into the head. This is normally one assembly when purchased. The straight rod has a threaded coupler fixed to it that is permanently attached. The angled choke rod that is in the engine compartment, threads into the coupler and has enough threads that you can adjust the final length to get the choke set correctly.


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bbodie52 wrote:Yes, the choke rod from the carburetor is threaded into the rod that extends upward from the coil on the underside of the cylinder head. To clarify...

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This is a view of the underside of the cylinder head, near the exhaust ports. The picture shows the mounting location where the choke coil is riveted to the aluminum head. A loose rivet is shown next to the rivet hole. When attached to the head, the metal coil responds to increasing cylinder head heat. It starts out when cold by applying spring pressure to the choke mechanism on the carburetor, forcing it into a closed position. As the engine heats, the coil contracts and gradually releases spring pressure on the automatic choke mechanism. When the engine is at full normal operating temperature the spring pressure is minimized, which allows the carburetor choke mechanism to move to the full open position.
If you need any replacement parts for your choke mechanism, they are available at Clark's Corvair Parts...

:link: http://www.corvair.com/user-cgi/catalog ... IN&page=56
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Part number C1168: AUTOMATIC CHOKE COIL/BRACKET-62-69,62-63 OWNER ALSO ORD C885 UPPER ROD,RETAINRS=C1168R

Weight: 0 lbs 6 oz
Catalog Pages(s): 16,56(46)
Price:
1 - 1 $ 19.70
2+ $ 18.15


Part number C1168R: ORIG STYLE CHOKE COIL RETAINERS SET/4 2 ORIGINAL, 2 OS & 1 DRILL BIT (1 SET/CAR)

Weight: 0 lbs 2 oz
Catalog Pages(s): 56(46)
Price: $ 5.30


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Brad Bodie
Lake Chatuge, North Carolina
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