Need a Climate Control Fast Idle Speed-up for 1968 DVC

[cadillacmike68]

Hi all,

I'm finally back and am still trying to get my 1968 DeVille convertible straightened out.

One item I found out is that I'm missing the Climate Control fast idle speed up dash-pot (and associated linkage and bracket).

I remember someone who rebuilt the carburetor way back (in 1999 or 2000) removed it stating it wasn't needed and only robbed performance.

And of course I believed him. Now I know better, but I can't find one.

From what I have found out, it is a 1968 only item (yahoo another one off year item    ) and it goes on the passenger side near the back (by the main venturis)

I need one and most likely, the brackets. Cadillac Tim doesn't have them, dbaers is on vacation.

Any recommendations or does anyone have one to sell or trade?

The dashpot should be simple, its the bracket and link (which I hope is still there, but I'm not holding my breath) that's going to be a PITA.



The engine is not stalling or anything like that, but when it gets hot here again, the temps will creep up gain every time I'm stuck in a traffic jam, which would be just about every time I go anywhere here.

I got everything else in the Climate Control working, Now I only need this missing item. Thanks in advance.

["Cadillac Kid" Greg Surfas 15364]

Mike,
If it is a "functional" thing you are after, it IS un-necessary for normal operation.  The idle speed up was a throw-back to the days when turning on the AC really did effect the idle speed.  It's sole function was to bring the idle speed up to something like 900 RPM in neutral, dropping to say 600 RPM when the car was placed in drive, thus allowing it to not stall.  With the Quadrajet and the 472, the effect on both power and carburetor "control-ability" of the AC Compressor is minimal. In regards to hot engine operation, the idle speed-up is not intended to do this, and any problems in that regard should be investigated elsewhere. Proper fan, radiator, fan shroud, and all baffles installed should insure maintenance of proper operating temperatures.
In regards to the dashpot, they are still available through several carburetor speciallist shops and as long as you still have your bracket you should have no problems.
If you really are set on the idle speed-up issue, you could get a (say71-73) anti-deiseling solonoid and bracket and wire it to the compressor circuit.  It would work the same on the throttle(rod) side of the carb.
Greg Surfas

[60eldo]

   Is this what you need?

[cadillacmike68]

Hi Greg.  I'm not sure where you are but it gets HOT here in FL in the summer and the traffic jams take a severe tool on our older cars without electric fans.

From the service manual page 1-19: "An Idle Speed up control is used to boost engine RPM when in Neutral or Park and is programmed by the Automatic Climate control system. This improves engine cooling and air conditioner performance when the car is standing."

I need every little bit of help i can get in the summer. I do not want to have to have an electric fan installed.  I have some time before summer comes along.

60eldo:

Your carb picture is also missing the idle speed-up. It would be on the left of the picture. That white dashpot  on the right is the primary vacuum break for the choke and air valve.

[35-709]

I have a '73 Coupe in Florida and have no overheating problems on the hottest days in heavy traffic with the AC on.  As Greg points out you could use a later anti-dieseling solenoid to accomplish what you wish to do by wiring it into the AC circuit if you can't put your old setup back together, but all things being as they should be you shouldn't even need that.  Below is a shot of the anti-dieseling solenoid in my '73, it has the green pigtail. 

[Bob Hoffmann CLC#96]

Mike,
I think you're gonna find it's a 75 series only  thing. Now, if someone knows what Cadillac calls the damn thing.. I'll  look it up in my MPB.
HTH, Bob

["Cadillac Kid" Greg Surfas 15364]

Bob,
The first two years of Quadrajets (67-68) took their que from the earlier generation of carbs (AFBs, Rochesters) and continued the idle speed up actuator, as Mike said, it was vertically acting, white "plastic" vacuum operated, and was located on the top at the rear of the passanger side of the carb.
Later QJs had improved (or at least re-tuned) idle circuits to compensate for the drag of the compressor.
Greg Surfas

[Glen]

That attached picture should help clear this up.  Its from the 68 Shop Manual. 

 

[cadillacmike68]

Yup. that's the same pic in my 68, 69, and 70 manuals.  We found one from a 69.

Further reading states it only kicks up the idle in Park or Neutral. I guess I'll have to stay out of big traffic jams.

Bob: Series 75 & comm chassis only for 1970, but all series for 1968 & 69.

35-709: Heavy traffic is fine, stopped in a jam with 50-100 cars in front waiting for up to 10 mins to get through a light is where the problem is.

[cadillacmike68]

Yup. that's the same pic in my 68, 69, and 70 manuals.  We found one from a 69. Lets hope it works.

Further reading states it only kicks up the idle in Park or Neutral. I guess I'll have to stay out of big traffic jams.

Bob: Series 75 & comm chassis only for 1970, but all series for 1968 & 69.

35-709: Heavy traffic is fine, stopped in a jam with 50-100 cars in front waiting for up to 10 mins to get through a light is where the problem is.

[35-709]

"35-709: Heavy traffic is fine, stopped in a jam with 50-100 cars in front waiting for up to 10 mins to get through a light is where the problem is."

Yes, been there done that sort of thing just north of my home on I-95 on my way back from the Boston GN, still no problem.  Hope there is nothing else causing your overheating.  Best of luck with it.

[Bob Hoffmann CLC#96]

Guys,
You are correct. That's what I get from trusting my memory. LOL! So... what does Cadillac call the part in the MPB??
Bob

[cadillacmike68]

"35-709: Heavy traffic is fine, stopped in a jam with 50-100 cars in front waiting for up to 10 mins to get through a light is where the problem is."

Yes, been there done that sort of thing just north of my home on I-95 on my way back from the Boston GN, still no problem.  Hope there is nothing else causing your overheating.  Best of luck with it.

Well, according to the manual I "shouldn't become alarmed" if the gauge goes up "past the halfway mark".  At least that's what it says.

Yeah, right, I recently had the engine completely overhauled and do not want to cook the bearings. The engine folks tole me that even the minimal .030 boring removes enough metal to make it run hotter.

However, while running down the road it stays right at the 1/4 mark. This means, at least to my logical mind, that it is cooling properly, otherwise the gauge would be steady at a higher point than the 1/4 mark.

On the other hand, it hasn't blown out any coolant (I put a 1969-70 closed system reservoir with the proper cap on it), and the engine metal temp warning light and buzzer didn't go off last summer, so maybe it's not a condition i should be highly concerned with.  I really don't want to damage the engine though.


Bob. The nearest I can come to the name is "Fast Idle Speed Up Actuator"