News:

Due to a technical issue, some recently uploaded pictures have been lost. We are investigating why this happened but the issue has been resolved so that future uploads should be safe.  You can also Modify your post (MORE...) and re-upload the pictures in your post.

Main Menu

1975 Eldorado fast idle question

Started by ChrisTabat, March 27, 2020, 10:08:46 PM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

ChrisTabat

I have been chasing my tail trying to resolve a relatively minor performance issue with my 1975 Eldorado.    I have replaced deteriorated vacuum hoses,   and have the choke set so that it starts well both cold and hot,  and runs and idles smoothly at all idle speeds.   My issue is that unless the ambient temperature is 80 degrees Fahrenheit or more,  I can't get the first level of fast idle to stay off.   In looking at the choke linkage,  it looks like the choke has to be fully open for the fast idle to be completely off.  Any slight degree of closure engages the fast idle cam.   If I set the choke leaner, I solve the fast idle issue but cold starts are terrible.    My question is:  is there a way to adjust that fast idle mechanism so that it engages at more of a closed choke setting?    I have the shop manual and it talks about bending a tang on the linkage, but I'm not seeing how that will help.   Suggestions appreciated.
Chris Tabat #31293

'68 DeVille Convertible, '75 Eldorado Convertible, '71 Chevelle SS Convertible, '11 Camaro SS Convertible
Bella Vista, AR

"Cadillac Kid" Greg Surfas 15364

QJ's have a fast idle adjustment screw "buried" in the choke linkage on the bottom of the carb on the passenger side.  It is also possible that the heating element of the choke has gotten tired and needs replacement.
Greg Surfas
Cadillac Kid-Greg Surfas
Director Modified Chapter CLC
CLC #15364
66 Coupe deVille (now gone to the UK)
72 Eldo Cpe  (now cruising the sands in Quatar)
73 Coupe deVille
75 Coupe deElegance
76 Coupe deVille
79 Coupe de ville with "Paris" (pick up) option and 472 motor
514 inch motor now in '73-

ChrisTabat

Thanks.  Took off the primary vacuum break and found the screw.   The fast idle speed is about right;  it just won't come off.    Choke heater sounds like a good next step.
Chris Tabat #31293

'68 DeVille Convertible, '75 Eldorado Convertible, '71 Chevelle SS Convertible, '11 Camaro SS Convertible
Bella Vista, AR

Tpicks55

There are a couple of videos on youtube that show carb set up.  Just put i rodchester carb and you can see them. Good luck. Tony
75 Eldorado Convertible
94 Deville Concurs
2019 Lincoln Continental
2016 Cadillac XTS

TJ Hopland

If you are looking for a new choke heater / coil I would look for a NOS delco one.   Even 15 years ago the aftermarket replacements tended to be pretty low quality and unreliable.       
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason