Chevy & GMC Vans

Hi Have a 86 4.3 tbi astro allegro motorhome. Air comes out of the right vents but when you change from a/c to say defrost it takes about 2 or 3 minutes before the change is made. Assuming this is a vacuum problem; but have checked most hoses and vac seems to be good. Goes to about 15 lbs and remains steady. Does anyone know if this is right? Also when you have the lever on hi cool and move it to Max cool it seems to stay the same. On other cars I think they have always got colder because it was recirculating and the fan seems to blow harder. What happens when you change on your van?
Thanks in advance for any help.

Welcome to the site.I am a huge fan of the Allegro/Provans Tiger XL style motor homes.When you get a chance please do post pictures of your rig.

I can't answer your questions,but I am sure some A/C experts here will help you out.Just give them a chance to catch this thread.

Again Welcome,

Gary

Since I can call you gary, gary I have just bought an 86 allegro motorhome made by
Tiffen Motorhomes in Red Bay Alabama. They made very few of them for just a couple of years. They as you say are closer to a provan XT which is the fixed Hard Top Model as opposed to the GT which is A Pop up model like the Sportsmobile Models. I have a couple of VW Westfalia Camper-vans but found them a little to small. As in no bathroom and as you get older you do not want to be too far from a restroom. The layout is very similiar to a Winnebago Phasar with two seats up front with two seats directly behind that swings and lays down to make into a bed then has a small kitchen with opposing bathroom and closet with a dinette in rear thats makes into a bed. Not very big but in todays gas market that's the point. I have only had it a short time and made two trips each about 250 miles but on both averaged about 17.5 mpg. Thats going about 60 mph and tanks are not loaded.
I will post pictures in the near future. Also there a aero lite which has the same layout but with a over the cab bed. They have long been out of business so not very many of them around

That is great mpg.I agree,that is the point about these style of MH's.

Boys around here based on Astro/Safari could show ya,if you every had a issue with the 4.3,how to do a V8 conversion and still get the same gas mileage or better.Might improve what you could tow with it too.Best part is these Mh's hold there value,so If you got it at the right price,it is a investment that would be hard to loose on.

Yes please do post pictures of the layout and the outside too.

Check out the NECO thread which is a yrly North Eastend Camp Out held on the 4th of July wk.This yr was in NY at Lake Bluff campgrounds.There is a number of campers here.

BTW:
This is a picture of my rig which I am still restoring.

Sounds to me like a main vac control line's leaking. Or, you're simply unlucky and you've got vac motor issues as well. You'll have to trace the lines and check out the servo motor with a known high-vac test line.

Hi Thanks for everyone's help. Problem fixed. Someone on the engines forum had posted an diagram from autozone that was also in alldata that was just for heat a/c. It had the colors of the different vac tubes coming off the control unit. Once I got these color which explained where and what each one controls traced down a leak to fresh air actuator. That then fixed the fact that max air was not getting colder. Also I found out that even this old a unit still had a fan speed relay that when put into Max air the fan speeds up as well. With both of these my air seems to work fine. I learn a lot during this project and know where and what most things that control vents defrosts and a/c flow do.

yeah i used the same diagram to fix my vacume leak in my 1992 astro it was the line that off of a tee from engine and teed off two way well the one going to the heater control valve and vacume ball was cracked and the one to the vac ball was broken in half so i fixed it now my a/c blows very cold quickly just the other day it was 104 degrees here in oklahoma with very little humidty the air coming out of my air vents on max a/c was 50degrees that night it was 90 degrees and i got 47 degree air!!