What's new
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

Will this vac routing work? (I even drew a pretty picture)

B

Blazer_Boy

1/2 ton status
Joined
Dec 16, 2000
Posts
1,669
Reaction score
0
Location
Sioux City, IA, USA
I'm still trying to correct the jumble of vac lines from the last owner. Basically everything emissions realted is about gone. It has an old manifold with no provision for EGR. All thats left if the vapor canister. He had some hoses hooked up wrong, some broken, and the ones not hooked up had masking tape shoved in them! I don't have emissions testing here but I'd like to at least get my vapor canister set up.
febc0898.jpg

if the pic is trying to be cool and not work, try this...
<A target="_blank" HREF=http://www.geocities.com/bigkern76/k5.jpg>http://www.geocities.com/bigkern76/k5.jpg</A>

<P ID="edit"><FONT SIZE=-1>Edited by blazer_boy on 03/21/01 12:10 PM (server time).</FONT></P>
 
I cant see a pic or access the site

Murphy's Laws on Life :
"It is a mistake to allow any mechanical object to realize you are in a hurry."
 
sorry i cant help you but just wanted to let you know the pic is working

77blazer see it at<A target="_blank" HREF=http://community.webshots.com/user/ssmith6333>http://community.webshots.com/user/ssmith6333</A>
JU74934.jpg
 
Well at least I know people can see it now, thanks. Can you see my special officer doofy? He needs to be resized but its alright for now.

febc0722.jpg
 
I can see the pics now

Murphy's Laws on Life :
"It is a mistake to allow any mechanical object to realize you are in a hurry."
 
I basically combined the 1969-75 standard emission setup with my 1982 PCV valve and vapor canister (no EGR in the setup because whatever manifold the guy before put on the crate motor is old enough it doesnt have it). I want get all new hoses and make it look nice. I tried my idea using whats left of the original hoses. Before they were all running to a little canister above the compressor a believe its called the Decel Valve. Anyways that was the last remaining piece and I routed it out. It idles MUCH better now with the new setup. It felt a little more peppy but I think thats just a placebo effect. I probably had a vacuum leak somewhere but whatever happened it helped.

febc0722.jpg
 
Your doing exactly what I'm doing!
I disconnected my AIR and EFE valve and the DECEL valve
but, not sure about keeping canister I might just keep the tank vent hooked up but nothing else It looks like your system would work from your great drawing but, I don't have my book handy, It looks like your far left canister hookup goes to your air cleaner but mine goes to a pipe by canister and along the lower radiator support and down the passenger side chassis but, I haven't traced where it goes Do you know?
also your vacuum advance from distributor goes to the far right port, mine is going to the center left, I don't know if your wrong or I am or if it matters but I am wandering if theres supposed to be a delay valve or something in the line or if its fine with nothing
All that Emissions junk can really screw you up!
Does your run fine without all that stuff and with stock carb
Mine does have the EGR but I disconnected it, which I don't think would cause problems since it doesn't on yours?

If it ain't Intimidating / It ain't a Chevy!
 
Hmm, I think something was getting stuck in my Decel valve because it would run rough intermittenly. I just roughly setup what I drew and it seems to run smoother. I think the only big downside to removing the stuff is that its a lil' groggy in the morning until it gets warmed up. That line by the frame goes to the gas tank. I'll have to see what I can find on yours. I got a chilton book that has 69-82 Blazers in there and I made the diagram up by basically copying the 69-75 setup. I changed how they had the PCV because they used the one with one end where mine has two, still exactly the same, the old one just used a T connector. The only difference is that they the have the Thermal vacuum switch is drawn outside the air cleaner, thats it!

I can draw up the 69-95 diagram this weekend for ya. I would use that and look at what your hood sticker says. I'm sure where the hoses plug into the carb is different but the routings will still work. Just have to combine the two. I have no idea about the EGR though. My mechanic put the vac advance line on the far right when he rebuilt the carb and fixed the distributor. He's been at it since 1957 and I'll just trust what he did. Some of the pics show a bunch valve crap comming of the advance and going to the middle left. I think you could probably go either or. Others (1980) have it going to the far right like mine. Sorry for having kinda of choppy paragraphs but Im looking at the book and blurting out random thoughts. All I can say is draw a diagram of what you have now, try your own stlye, try mine. Keep which ever works good and you feel comfortable with and like. I'll give ya an update after I see how it does in the morning Make sure to cap of the unused spots on the carb.

febbb8ba.jpg
 
I switched over to the single PCV valve to, and basically cut off all the lines for the canister except BOTH, gas tank vents but, before I started this, I thought there was only one, I'm figurin one tank vent is the return line?

After figurin with your drawing, wouldn't your canister valves be open all the time? and lets say you fill your tank plump full and gas goes down the line, wouldn't your engine start studdering, at low RPMs (doubt it would do anything at higher speeds) unless its only vapors and thats it, and theres no way gas can get down the line?

I'm thinkin I would like to keep that canister and hooked up but, they had so much other junk hooked up like delay valves and TVS (thermal vacuum switch) hooked up to it so it only sucks vapors until the engines hot and if I'm not mistaken It only turned on the canister valves in average RPMs
I don't know its gettin to be so many variables on this
But if your gettin it out of first-gen chilton book it should work to copy onto a 84 as long as its just that but I don't know if they were the same Q-jets with the same ports.
If you figure out a 69-95 diagram ,If its no trouble, I could use it
I'm gonna try movin my advance to the far right port!

If it ain't Intimidating / It ain't a Chevy!
 
The only way it could suck gas is if the vent line in the tank were down in the fluid and there was enough vacuum to completely fill the canister. The tank is designed to make sure that the fuel will not reach up to that vent line. The idea of the canister is to keep your gas tank from bulging or contracting due to tempature differences. They used to use a vented gas cap to ensure this would not happen. The problem is that if you have enough money to fill your tank plumb up to the filler pipe and it got alot warmer after you filled then fuel would spill out from the vent (thats what Chilton said). If several vehicles were parked under the sun then all those vapors would evaporate into the atmosphere. The idea of the canister is to capture these fumes and keep them until the valves are opened. The vacuum from the carb pulls these valves and sucks in the vapors. So basically instead of wasting these vapors you can use them. I'm thinking they have a line going up to the PCV to make the gases from it burn a little better. There is only one line going to the tank.

With my setup with the mismatched manifold it will run rough if you try to hot rod it before it is completely warmed up. I just put my new lines on tonight. I used the goodyear hoses rated for fuel. The larger hose from right valve of the canister and goes to the PCV is 1/4". From the PCV to the bottom middle of the carb is 3/8". The valve next to the right one uses a 3/8" hose to the middle of the carb. The line on the far left for the aircleaner is also 3/8". The lil' line by the by the canister that joins to that little Y connector is 3/16". Once your done just fire it up and listen for a hiss indicating a leak. I had one because the guy at the parts store sold my 5/16" instead of the 1/4", corrected that and everything runs great!

febbb8ba.jpg
 
Thanks for the pic, I think I'm gonna get all new vac hoses and gas proof also and if I have extra I can always use it down the road,
also gonna pick up a timing light because I disconnect the hose for advance and she'll quit or studder , I had a shop do the timing and I bet they didn't even disconnect it

But, I do have two lines on canister that go to pipes and back too the tank (go figure)

I have two TVS, one on my Intake , and one on my thermostat housing, the one on the thermostat has two nipples broken off but the other one is fine so I think I'll use that one like in your drawing

what do you have your main Intake vacuum hooked up to
I'm figurin just your climate control and trans modulator
Thats how I've got it, but I have one more line going to
some kind of soleniod on the firewall with only one vac line on it and a two or three wire hookup Do you have this?

Your drawing shows three lines on canister but what did you do with the fourth one, My canister has two tank vents
does that yellow line open the valve all the time and the red line sucks vapors and then you blocked off the second canister valve ? or maybe you don't have one

it looks like this drawing will work
just have to try it I guess
Again, Thanks

If it ain't Intimidating / It ain't a Chevy!
 
The 69-75 canister only had three openings. Hmm, mine only has one line to the tank, throw in another another variable, lol. I have NO idea what that little valve on the firewall does. I'm thinking it has to do something with the throttle position. Since I've had the truck and after I got the carb done it has never been hooked up. If anyone can please tell me what it does and if should hook it up. My current vac setup is exactly like the pic up top.

febbb8ba.jpg
 
I screwed up, wish I had the truck right by the PC
that return line I was talkin about doesn't go into canister
It goes right by there with some kind of vent cap on it with a loose cover
I'm just gonna have to trace it all the way back maybe its a trans breather

I was wandering if that firewall thing maybe converter lock-up

If it ain't Intimidating / It ain't a Chevy!
 
hey Blazer Boy how you get pictures on here
Did you use Microsoft Paint to make the drawing
and where does everybody get those pics on there posts

If it ain't Intimidating / It ain't a Chevy!
 
I just drew them on paint and put the pics at <A target="_blank" HREF=http://www.zing.com>http://www.zing.com</A>. Now i gotta find out what in the heck it is. I keep my truck in 3rd because I haven't taken my 3.08s out yet and I don't want it to hit over drive. Mine usually locks up somewhere around 45, with out it hooked up.

febbb8ba.jpg
 
You must log in or register to reply here.

Latest Posts

Top Bottom