rhett838

1) On the small end of the water valve, what vacuum line is supposed to hook up to that, and where does it go to or come from? I refered to my 1969 chasis manual, but I had no luck

2) When I changed out my manifold, I didn't reinstall the electric throttle solenoid thing b/c I was told I didn't need it, but do I?...and that leads to question 3...

3) When A/c is on the car begins to slowly overheat and the idle slowly starts to sputter and eventually the car wants to die.

Is the water valve not functioning correctly, b/c the little vacuum line isn'y hooked up correctly, and causing it to overheat?

And is not having that electric throttle solenoid thingy (feel free to tell me the proper name for that) hooked up causing my car to sputter out?

As always...THANKS FOR YOUR INPUT!

I'm not blowing smoke up your ****, but I've really learned alot in the year I've had my olds thanks to you that reply. I think I've upgraded from a novice to a senior novice.

71 Cutlass

You can always adjust your idle to a higher rpm setting during the months when you run A/C to help the car from dying on you (as opposed to getting a "thingy"). The water valve on my 71 uses a vacuum line that goes through the fire wall and connects to a nipple on the back of the A/C and heater controls, yet not every car uses this vacuum line according to my 71 manual.

67442nut

If you have a heater control valve ("water valve"), the vacuum line is what controls the opening and closing of it.
When you turn on the A/C, the valve closes to keep hot water from flowing into the heater core while the A/C is running.
It is open when the A/C is off.
Some valves require vacuum to open and some require vacuum to close.
In either case, the vacuum line that controls it needs to be connected for the system to function correctly.
If the valve has been replaced, it is a common problem for the replacement valve to have the wrong function
if someone doesn't know which one he needs.

Is the "electric solenoid thingy" mounted near the idle adjustment on the carb?
If so, it is the fast idle solenoid.
It increases your idle speed when the A/C is on to keep what is happening from happening.
Sounds like getting this stuff installed correctly may cure your problem.

rhett838

"In either case, the vacuum line that controls it needs to be connected for the system to function correctly."

So where does that vacuum line come from? My manifold ports are pretty loaded...one to the brake booster, one to the heater, and one that goes to the carb/tranny/thermostatic vacuum switch. Do I "T" something off?

rhett838

hmm...the original 2bbl manifold has 4 vacuum ports 1 in front of the carb, 3 behind. The new edelbrock manifold only has 3 ports 1 in the front 2 in the back. I did cap off a large port in the back right corner (1 inch?) and a smaller one in the front right corner (1/2 inch?). Can I use one of those a another vacuum port?

71 Cutlass

He stated he does not have one hooked up on the carb. That is why I suggested simply turning the idle screw up...done it this way for years.

The 71 manual for my car, as I said, states that the white vacuum line is cut off (this is the line that goes to the water valve) and not used on L-6 engines. Not knowing what engine Rhett has, I threw that in as possibly imortant info. Page 1C-17 in the manual.

Rhett--check your manual again...info has to be there in the Air conditioning section. I found this info in my assembly manual as wel.

rhett838

Rhett--check your manual again...info has to be there in the Air conditioning section. I found this info in my assembly manual as well.

Yeah, It says the "white" hose for the B and C bodies. But let me tell you, there's no white vacuum hoses in my engine compartment.

The A body diagram has no vacuum hose on the water valve. The one I replaced from the old manifold did though. Is it possble I have the wrong water valve? Is there such a vavle w/ no vacuum line?

rhett838

BTW it's a SB 350...I've heard of a L-6 but never seen one. Do they really exist? LOL!

71 Cutlass

Rhett,
I'm not like Joe P. (wish I was) with every make ,model,option, etc. known to man on the tip of my tounge, so I cannot give you a specific answer regarding your model and year vehicle w/ regard to the water valve/heater control valve options. Hopefully someone with your model and year car can help you out. Also, that line has a white stripe on it, as opposed to being totally white...if that's helps. As I said, following the diagram for my car, it shows that vacuum line going to the third farthest nipple to the left on a round piece that is connected to the backside of the heater and A/C controls. I accessed that nipple through the clock area of the instrument cluster (removed the clock) when i connected my water valve this past weekend.

Lady72nRob71

So you have a 69 Cutlass with a 350 2bbl carb (originally)? This is vital info...
Adding this to your sig would be a good help for later questions.

The water valve in the early 70's and later is controlled from a vacuum hose coming from the heater controls. Black hose with white stripe (maybe faded and dirty by now or pulled off from previous owner.)

Whether it is open or closed should not contribute to any overheating conditions.
If memory serves, in the early 70's, the valve is closed with no vacuum applied.

It is possible that the '69 A body did not use this setup until the 70's. If not, to use the heater, just connect the heater valve vac hose to manifold vacuum. (T into a small hose coming right off the intake manifold).

Side info:
The heater valves for the 80's Cutlass require vacuum to close (failsafe mode).
The L6 was available in 71 and was the last year for them.

joe_padavano

The vacuum diagram is in the chapter on the A/C system (chapter 1)

Once again, GM is not in the habit of installing unnecessary parts.

Which is WHY GM installed the idle solenoid.

Yes

No. All the heater control valve does is shut off water flow to the heater when the A/C is on the MAX position, to ensure maximum cooling of the air.

Yes.

joe_padavano

Stop that! I still have to fit my head through the office door to get home tonight...

67442nut

I understood why you suggested turning up the idle screw in the summer time and back in winter.
He said he didn't reinstall the solenoid after changing the manifold, so I assumed he still had it.
This is why I suggested he reinstall it, so the idle would work as it should.
I didn't intend to imply that anything was wrong with your suggestion.
The only thing is that when the A/C compressor is not engaged, the engine will idle fast.

Since I'm doing a lot of assuming, I thought it was fair to assume that he has a V8, since the L6's are pretty rare.