From asking questions, reading posts, and looking in the manuals..

I have decided that the only stock Miata vacuum line I am keeping is the charcoal canister purge. On my 1996, this canister ran to the gas tank on one end and the other end ran to a solenoid controled by the ECU.

What is the equivelent electrical control from an 89 302? How should I connect it? Should I just delete this all together?

The other vacuum lines I am running from the 302 intake vacuum tree are PCV, Brake booster, and EGR. That is all the vacuum lines I should need to get this car running and passing emisions.

Soooooo close!

 

This page:

Fuel Injection Technical Library

has a lot of info on the Ford EEC's

I think what you want is the CANP pin, which varies from model to model.

Mike

 

Is there not a check valve you could put in the solenoid's place.

My Volvo's don't have any electrical valves in it's EVAP system...and I'd trust you could reconfigure it to work, without that solenoid.

 

Use the Mazda charcoal canister & the Ford Purge valve. The valve's electrical connector should be on your Ford EFI wiring harness. The valve is controlled by the Ford ECU.

 

For those that don't already know,

WHAT"S THE PURPOSE OF THE ELECTRONIC VALVE???

What is it's job? When does it open/close, and why?

I get that you're using a EMS that'll support it, but what if you're not?

Come to think of it, I don't think there's a valve at all in my Volvo setup..
It's two hoses from the Throttle Body to Charcoal Canister, one larger than the other,
And there's the one long line back to the tank....might be a check valve by the tank, but isn't there one in your Miata.

Can't you just run that one line, directly to vacuum, and ditch the valve all together?

 

You would probably get a check engine light on, & the car would run like it had a vacuum leak. Why not just use the purge valve?

 

[QUOTE=mylesofsmyles;4177]

WHAT"S THE PURPOSE OF THE ELECTRONIC VALVE???

What is it's job? When does it open/close, and why?

The purge valve is controlled by the Ford's ECU. It opens to allow gas fumes that are trapped in the charcoal canister to be vented into the intake manifold rather than be released into the atmosphere.

 

Still think a check-valve would git-r-done.

 

There is a check valve on the Miata tank. Although I have the purge system active on my car, the tank would build up some serious amounts of pressure in just a few minutes of driving. My garage would reek of gasoline after even a short drive. I disassembled the gas cap & found that the "screen" was stopped-up. After cleaning it, the tank was still building pressure. Blowing air back through the tank vent hose at the charcoal canister (with the gas cap REMOVED) dislodged the stuck check valve. I no longer have a pressure build-up in the tank. My car runs MUCH BETTER after a longer drive cycle due to the lower fuel temperature. The garage no longer smells of raw fuel.

 

So you had a bad check valve?

Are you running it straight now, or with the solenoid?

 

The check valve was stuck, not allowing the vapors & fuel tank pressure to be released to the solenoid. The tank had so much pressure built up that it would almost blow the fuel cap out of my hand when I went to remove it. Now, with the purge valve & check valve working , the fuel temps & IAC temps are much lower.

 

I'm still confused as to what your setup WAS, when that happened.

That was running direct, from canister to check valve at tank, or with the stock purge valve?

Maybe I'll just swap the EVAP system of my donor car's engine...




Looks like Volvo has a Vacuum valve built into the charcoal canister, and a "roll-over" valve in front of the tank.

Just swap the Mazda Check Valve for a Volvo Roll-Over Valve, and the charcoal canisters...

Seems easy enough.

 

I am & have been using the stock evap system from my 1991 Miata. The ONLY changes are the Ford canister purge valve replaced the Mazda unit. It has the same function. It just plugs into the Ford wiring harness without having to adapt the Ford plug to the Mazda valve.

 

Looks like all you need to do is use the Volvo charcoal canister & vacuum valve assembly in place of the Mazda canister & electronic valve.

 

Vacuum valve in integral with charcoal canister, on Volvo unit...

Going to trade the check valve at the Miata tank for a Volvo Roll-Over Valve


Devil is in just the size of the Volvo unit...I'll snap a picture...

Trying to mount it, like a ABS style wash bottle....only in the PASSENGER fender.

Hitting the yards in a few, so I'll see if a Volvo 740 style bracket will help with installation.

 

[QUOTE=mylesofsmyles;4202]

Going to trade the check valve at the Miata tank for a Volvo Roll-Over Valve.


Just use the Mazda tank valve. I see no reason to have to change it.

 

Hi Tbone - I know this is a really old thread but hopefully you can help me since you had this all connected.

I'm installing the evap system, the miata canister has three hose connections, two on the top, one on the bottom..

The bigger one on top connects to gas tank, the other smaller one goes to the new ford evap solnenoid inline to to the intake vacume tree...

What I'm uncertain of is the line under the evap can, my understanding is this lets air in the evap can to replace the air/fumes purged..


where i'm baffled is when i have the evap can out and i blow through any of these lines air comes out the other two... would this not mean that the gas fumes would come out of this third vent hose instead of being trapped in the can? Would it not also mean that when the solenoid purge valve is open the car would basically run like it has a vacume leak pulling tons of air in from that open third vent hose?

???? does not make sence to me...