Vacuum tube removal + A/C + Cruise

[mindlos]

As you know I gave the stock vacuum setup the mafia treatment. At the time I had cruise but no refrigerant thus my A/C did not work. After removal of the tubes cruise went bye-bye.

My intuition has always been that the tree on the strut tower with six connections (facing the master cylinder reservoir) was involved in either or both systems. Out of trial and error I applied manifold vacuum to each of the ports at a time and went driving.
The conclusion from that was that in order for cruise control to work there has to be manifold vacuum applied to the bottom row middle port. Otherwise the cruise indicator comes on but diagphram cant be actuated to keep the throttle at any position. The system involved includes the black canister and big ass diagphram by the power steering resevoir, probably some solenoids too and the stuff inside the fender.

Confident I would get my AC working I bought some R134A recharge, oil, and adapter. My system was already empty but I still made sure I got the stuff that said it was compatible with residual R12. I filled it up with oil then R134A with the A/C set at full blast. As soon as I got the R134A in there my RPMs plumetted and started blowing chilly air. It turns out I do not need any vacuum for the A/C to work as long as it is topped up. I had to set my baseline RPMs to about 1300. With A/C on it comes down to about 800 and the radiator fans run all the time.

I removed the A/C load diagphram so that will have to go back so that my idle is not so high without A/C. There is a solenoid on the strut tower would normally used to controll the A/C load diagphram. It takes manifold vacuum via the top row middle port on the tree and routes it to the bottom row back/firewall port for the A/C diagphram hookup. That output port has a vacuum signal only when A/C is on in order to raise RPMs due to load. Apart from operationg the diagphram there are no vacuum lines needed for A/C to work.

I'm a story teller by nature. Sorry about the long post. Any questions let me know.

~ mindlos

[A20A1]

Nice... I may need to organize things a bit before I stick this one up top. There are already way too much threads up there.

[mindlos]

I put back my A/C diagphram so that my rpms are not wack doing high idle. Works well (I guess thats the way its supposed to). Only thing is I had to was go back to a vacuum secondary since I had to put back that flap on the other side of the throttle shaft. Now I wonder.... when does the secondary open on the vacuum? Any way to make it open a little sooner??

[DanG86LX]

Agree with Mike, this is a great thread and should be at the top.
..only, the title could be different, like:

Reinventing vacuum after vacuum removal!

$#!+, sound like a contradiction.
Any other ideas?

[mindlos]

Ya, something like "How to keep A/C and Cruise after vacuum line removal." I'm not very good with brevity so Mike will figure it out.

I'm still seeing some people say they dont know how to keep these working so some people definitely missed it.

Either rename and sticky or have an action item to update the Howto(s) so that anybody who reads the howto automatically gets this info too.

[3rdGenFanatic]

How can this be accomplished?

[3rdGenFanatic]

So let me get this straight.. I can use A20A1's diagram and STILL keep my A/C?!

[mindlos]

yup, as long as you keep the AC diagphram to manage load rpms.

[mindlos]

'm on vacation in Swaziland till the 22nd, but read the other thread again. you dont need anything to have A/C. You just need the diagphram to raise the rpms to normal idle when the compressor is leeching.

[3rdGenFanatic]

Thank you very much. You've been a great help mindlos.

[racerx]

Originally posted by 3rdGenFanatic
You've been a great help mindlos.
:werd:

[mindlos]

http://www.elvis.com.au/shopelvis/images/book_thankyouverymuch.jpg

[Mike's89AccordLX]

I can help you he helped me and I remember everything. Oh you gonna send out that money for the strut bar?

[mindlos]

For those who need to see what I was talking about here is a pic. I did it in paint coz I'm at work. I'll redo it in photoshop at home. Just trace the lines since I did not color the route paths.


http://www.mindlos.com/~mandla/driverfender1.jpg

[shepherd79]

nice man. good work.

[thundertank]

ok thats all good but how the hell do you get the diaphram to raise the rpm?

[mindlos]

First of all make sure your idle rpms without load (A/C off) are good. Then you turn A/C on and set the fan speed on the climate control to full blast. This will make the radiator fan run full-time and the compressor load will drop engine rpms to a point whether it is puttering. The A/C solenoid will also route manifold vacuum to the diaghram. At that point you adjust the screw on the A/C diagphram (screw in to make contact with the flap and give more throttle) until the rpms rise back to normal idle level.

At this point you should be golden.

EDIT: Hey thunder I just saw you have a weber. There may not be anything you can do unless you find a way to attach the diagphram and link arm to the carb and throttle pivot respectively. I have no idea what that would entail.

[thundertank]

see thats what im saying im trying to find out how to get one to work someone on here was saying i should use a gm idle up solenoid but im not sure how to rig that up.

[A20A1]

The diapragm has a spring on the inside... when there is no vacuum there is no resistance to the spring and the spring pushes the idle open... when there is vacuum the diapragn retracts and the idle drops untill vacuul is low enough for the spring to take over and raise the idle again.

[accordlxi2.0]

hold on . . . . . . . . i thought that when u turn the a/c on, the vacuum the suck's the diapragmwhich cause's the rod to pull on the throttle make's the idle raise.
plus the a/c solenoid connection does'nt work.

[A20A1]

oops I was talking about the regular idle diaphragm...