Home page

Cool! NEW FEATURE! Add "Your Corvette Story" today

C3 Engines

Going back up to high idling speed (1/12)
 1/26/19 9:45pm
Christian
Standard Member
Send Private Message

Houston, TX - USA

Vette(s):
1971 LS5 Convertible 4 sp


Joined: 2/25/2003
Posts: 171

As the engine has been idling high while warming up, I usually get it to slow down to normal idle speed by briefly striking the gas pedal, when I believe it is warm enough. Normal routine.

Something new however: Driving the car at normal operating temperature, the engine would idle at high speed – like at traffic lights, for instance – unless I repeat the procedure of briefly kicking the gas pedal like I normally do a few minutes after warming up. Every time, at every traffic light. Otherwise it would just idle at 1,500 rpm. Really annoying in the traffic.

Like if something was “sticking”. Any advice?  



|UPDATED|1/26/2019 6:45:55 PM (AZT)|/UPDATED|
Our Sponsors help support C3VR
Sponsor Ad

Re: Going back up to high idling speed (2/12)
 1/27/19 2:20am
73shark
Standard Member
Send Private Message

Overland Park, KS - USA

Vette(s):
1973 Orange Metallic Coupe (orig owner), L82, 4 spd (WR), PS, (A/C & PW (I installed from wrecked 73)), leather, AM/FM Stereo, ran with '65 FI unit earlier & will again some day.


Joined: 7/9/2003
Posts: 549

Something in the choke pulloff mechanism is not working properly. Could be the choke stove. Everything should be free and slightly loose.

______________

1973 L-82 4 spd

Re: Going back up to high idling speed (3/12)
 1/27/19 11:37am
Adams' AppleLifetime Member
Lifetime Member
Moderator
Send Private Message

Duncanville, TX - USA

Vette(s):
#1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas


Joined: 11/8/2003
Posts: 19623

It's possible the throttle blade shaft is gummy, or the blades themselves. Might be time for a good cleaning on the carb, assuming there is no issues with the choke. I have seen many times the secondary throttle blades not returning to closed position due to stickiness. 

______________
Joel Adams
C3VR Lifetime Member #56    

My Link


(click for Texas-sized view!)
             NCRS

"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
Re: Going back up to high idling speed (4/12)
 1/27/19 12:40pm
Christian
Standard Member
Send Private Message

Houston, TX - USA

Vette(s):
1971 LS5 Convertible 4 sp


Joined: 2/25/2003
Posts: 171

Forgot to mention that the carburetor was just entirely taken apart, thoroughly cleaned and professionally tuned. The engine runs really smooth, idles nicely (when idling)and I feel I got all the power back.
This is the only issue I have with it.
Re: Going back up to high idling speed (5/12)
 1/27/19 2:24pm
73shark
Standard Member
Send Private Message

Overland Park, KS - USA

Vette(s):
1973 Orange Metallic Coupe (orig owner), L82, 4 spd (WR), PS, (A/C & PW (I installed from wrecked 73)), leather, AM/FM Stereo, ran with '65 FI unit earlier & will again some day.


Joined: 7/9/2003
Posts: 549

Sounds like it's time to take it back to the place that professionally rebuilt it and ask them what's wrong.

______________

1973 L-82 4 spd

Re: Going back up to high idling speed (6/12)
 1/27/19 7:50pm
Adams' AppleLifetime Member
Lifetime Member
Moderator
Send Private Message

Duncanville, TX - USA

Vette(s):
#1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas


Joined: 11/8/2003
Posts: 19623

It's also possible the throttle blades might be hanging on the carb base plate gasket...seen that many times too, with kit gaskets.

______________
Joel Adams
C3VR Lifetime Member #56    

My Link


(click for Texas-sized view!)
             NCRS

"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
Re: Going back up to high idling speed (7/12)
 1/27/19 8:08pm
Christian
Standard Member
Send Private Message

Houston, TX - USA

Vette(s):
1971 LS5 Convertible 4 sp


Joined: 2/25/2003
Posts: 171

OK. Apparently, that was nothing more than the cable sticking in its sleeve. I tried to inject WD40 in it, from the carb end, and it looks like it works now. Will see.
Re: Going back up to high idling speed (8/12)
 1/27/19 8:29pm
73shark
Standard Member
Send Private Message

Overland Park, KS - USA

Vette(s):
1973 Orange Metallic Coupe (orig owner), L82, 4 spd (WR), PS, (A/C & PW (I installed from wrecked 73)), leather, AM/FM Stereo, ran with '65 FI unit earlier & will again some day.


Joined: 7/9/2003
Posts: 549

If the WD-40 doesn't work, try silicon the next time and it won't attract any type of dirt.

______________

1973 L-82 4 spd

Re: Going back up to high idling speed (9/12)
 1/27/19 9:04pm
Christian
Standard Member
Send Private Message

Houston, TX - USA

Vette(s):
1971 LS5 Convertible 4 sp


Joined: 2/25/2003
Posts: 171

Good idea. Thanks!
Re: Going back up to high idling speed (10/12)
 2/1/19 9:23pm
Wally71Gold Member
Gold Member
Send Private Message

Palos Heights, IL - USA

Vette(s):
1971 LT 1 4spd Coupe numbers matching #s114893


Joined: 2/8/2013
Posts: 12

I found that my problem with high idle speeds on my 71 Lt1 was sticking flyweights in the
distributor. After we cleaned and reset the dist. it ran fine.
Wally71


______________