Help - Vacuum tube disconnected

Yes, I did jack a wheel and they are definitely in 4WD.

I replaced the vacuum hose from the blue valve to the engine and I was not able to shift it back into 2WD, I then took off the blue valve to see if it was functional - I wasn't sure if it had inhaled some dirt/dust. I tried blowing through it on both sides but it would not allow any air to pass through.

Is it possible that I will need to replace the blue valve - and is it possible that it could be blocked with dirt?

If yes, where could I buy one?

EDIT: I found the exact piece on ebay.

It’s a check valve and stops the engine intake from getting excess air if you have a leak in the vacuum hubs system, see the following

www.bigjimny.com/mediawiki/index.php/4WD..._failure_diagnostics

The valve will open to let a vacuum through, ibut stop if the vacuum doesn’t build up in the 4WD system. It might be it will only work with negative pressure and not by blowing.

Yes, it could fail and yes replacements will be available, which country are you based in? I would imagine you will get one on eBay.

For a quick test, bypass the valve and see if that makes the 4WD work, if it does then you need a new valve. If it doesn’t work, you might need a new valve and need to find another problem.

Just out of interest when you started this thread the pipe was disconnected from the manifold and that would have given you an air intake leak, it might have played havoc with the engine running correctly.

If your hubs and transfer box are stuck in 4WD then you run the risk of it damaging the transfer box and/transmission. You could follow the guidelines in the wiki on how to make an emergency fix or you could take the hubs off, push them back in to 2WD and disconnect the vac lines to both hubs, you will lose 4WD but at least the car will be driven until you get a permanent fix.

Oh Ok, thank you. That's very helpful. I'm in Scotland.

I'll give that a try tomorrow.

Try the BigJimny store for a new valve, see the banner at the top of the page. Or email/message Martin Lines, he runs the website and store, he will know where to get a new valve.

Robin

The blue valve is a non-return valve. (Check doesn't mean what you think - it must be something to do with checking (as in stopping) reverse flow)
You should be able to suck through it from one end only - the engine side.
It should blow through one way too from the tank side, but probably needs a lot of puff.

The purpose is to let the engine build up a vacuum in the tank, every time the manifold pressure is below tank pressure it sucks some air out of the tank. When the manifold pressure rises because the throttle is open the vacuum stays in the tank.

 

Hi all, I got the Jimny back into 2WD!

Here was my process for anyone who encounters this specific problem in the future.

I replaced a section of vacuum line from the blue non-return valve to the engine. The car still did not want to shift back into 2WD.

I then entirely removed the blue non-return valve and both pieces of vacuum line that were attached to it on either side, and used one longer piece of vacuum line to bypass it entirely and connect the engine to the rest of the vacuum system. I then started the ignition, waited a couple of seconds and pressed the 2WD button and it changed back into 2WD.

I will buy a new valve to replace the old one - but I'm a little curious as to why the hose came away from the engine in the first place.

In any case, thank you to Facade, Dr Robin and Motacilla and Jackonlyjack for the advice