Where is the purge valve located..and what does it look like ?

 

I'm going to have to redo all the stuff in my truck that you're doing now. The PO unhooked all the emissions equipment and the EVAP system, so I was plugging vacuum ports where they put bolts in vacuum lines to plug the ports themselves. I'm plugging ports and re-running hoses, and the more I do, the better my motor runs! So, don't feel discouraged. Just do a little at a time and it'll fall into place for you.

Here's a couple of photo's I think would help you out a bunch. One is a vacuum diagram I stole from a user on here, I forget who it was. The other is the inside shot of an engine compartment. Look up near the PCV valve at the back of the valve cover near the firewall, and you'll see the purge valve. It connects to the smaller port on top of your PCV valve on the valve cover and runs to the purge valve (the greenish UFO looking thing in the photo).

Also, thanks for posting on this. I was about to look up some more stuff on my EVAP system and this helped me out a lot.

EDIT: And for what it's worth, that is NOT my engine bay in the photo! Mine looks a lot nicer.

 

Here's another image of the purge valve. If imageshack resized it for me, you should be able to see it better. Like what I believe was mentioned earlier, it's either a green like this, or black. One vacuum line comes off the top of the PCV, the other line goes to the ported vacuum tree next to the radiator hoses at the front of the motor (as per the diagram posted above).

 

That is a good picture of the Purge Valve.

You need to be careful posting generic information like in that diagram you posted earlier. This is because there are several 100 different engine calibrations and each one has a unique way of hooking the vacuum lines up. Also each engine calibration can use specific engine parts that are only applicable to one engine calibration code. You should always follow the diagram provided on the emissions lable, located on the trucks radiator support for proper routing of vacuum lines.

 

Very true. However, the diagram was posted as a general reference for how to route the vacuum lines on his motor. Like you say, always follow the emissions label, because that's how the motor is supposed to be set up. The emissions label on his truck and my truck both show the same routing as the one for the diagram I posted, so I believe everything will be just fine. He needs to take into account though, that the diagram I posted is for one charcoal canister (single tank) and not two charcoal canisters (dual tank).

Good luck with your truck man!

 

Could I just bump this thread for a minute?

Can one of you gurus validate my plan here to set up a simple EVAP system, since most of my emissions stuff is missing, and I dont have an available ported vacuum connection on my carb.


Fuel Tank --> charcoal canister
Bowl Vent --> Tee <-- charcoal canister
Tee --> PURGE CV
PCV top port <-- PURGE CV
Manifold Vacuum --> PVS --> PURGE CV

This way, fumes should be available to enter engine only when engine is at normal operating temperature. Yes, during idle also, but I dont have any more Ported Vacuum available.. I only have one, and thats for distributor advance, so I would like to run it from the manifold tree.

This should work, no? Just logically?

I know on the vacuum diagrams, the vacuum for the purge CV goes through a maze of connections and fittings and gizmos, ... I dont have any of that stuff in my truck..


1980 f100 4.9L

 

FWIW..Years ago I eliminated the 2 broken canisters by running both lines to a "T" ..then coming off that with a line to a port on the carb spacer..Truck is '84 F-150..351W-HO..Runs fine..

 

Deleted....

 

Sorry, but I get lost in your verbal diagram. Are there two tees? It seems like the bowl vent, charcoal canister, and Purge CV (to PCV top port) are on one tee. But I also see that manifold vacuum goes through the PVS to the Purge CV. What am I missing?

Also, I'm not sure how big of a "leak" the charcoal canister provides. Nor do I know what the "PCV top port" does, as all the PCV valves I've played with have a blanked-off top port. But, on the lack of another ported vacuum connection, there is no reason you can't put a tee in the line from the carb to the vacuum advance and use that.

 

You're sure of this? I dont think you're supposed to just tee into a line.. the vacuum would drop for the distributor no?

Here's what I want to do:

http://img844.imageshack.us/img844/6587/mwi5.jpg


Uploaded with ImageShack.us

The canister purge valve would only get vacuum when the engine is warm (because of the PVS)

In this guys picture from the previous page, looks like the PURGE CV has 3 connections, so thats what I sort of copied

 

My problem is that I don't know for sure how the Purge CV works. And, the diagram shows one port goes to R, but I don't know what that is either. So I'm not much help. Sorry.

As for tapping into a vacuum line, you can do that as long as all you are doing it to control something. In other words, you can use the vacuum for two or more things as long as they don't admit a lot of air into the system. Let me give an example: The vacuum for the HVAC controls, the cruise control, and the automatic transmission all come off of a little plastic manifold, which is essentially a tee. Works fine since none of those items admits any appreciable amount of air into the system so the vacuum stays up. But if you hooked the PCV system to that little manifold the amount of air the PCV system admits would kill the vacuum so none of those items would function.

Having said all that, I think the Purge CV uses vacuum on the middle port to open the valve such that the outside ports are connected to each other. If that is true then you can tee into the ported vacuum and be fine. And, I think it will work the way you have it drawn.

 

We need Ralph.

 

Agreed. Where's he been?

I've not played with any of the various vacuum controls Ford used on the emissions systems. I can guess what they do, but that's not very helpful in a situation like this.

 

That "R" is actually a "B", its on my sticker too. To the left of that diagram will be some instructions on how to tune the carb, fast idle, and it just says "disconnect vacuum at "B" to do it properly.

And I understand now what you're saying now with the vacuum "T"-ing. I still feel kinda iffy about it just because the distributor is so important, and the PCV system is connected to this evap thing after all.. so I hope I can make it work without teeing in.. To your point though, on my truck's sticker it showed EGR and DIST vacuum coming off of the same point at the carburetor. I wish I could see a picture of someone's being hooked up that way.

Tomorrow I'm gonna try to source the PURGE-CV somewhere.. PO removed it

Anyway I appreciate the replies, thanks.

 

I understand your concern, but just think about how the things are hooked to the plastic manifold on the firewall. Anyway, maybe it'll work well on manifold vac so it won't be a problem. Good luck, and tell us how it goes.