How do I test / clean out the WUR?

Hi Guys,

My 1.6 '81 Gti starts fine then revs slowly drop to a really lumpy (400-500) to the point of trying to stall. When I've been on a good run its idles about 850 so its just a cold issue which leads me to think it might be a WUR issue?

I've searched the forum and can see that I need to test the plug for voltage and the WUR for resistance but cant find the correct values anywhere?

I've also seen that there is a filter which may be blockedin the WUR?
- How do I find / remove this?

Or are there any other ideas of what it might be?

Thanks for your help guys,
Mike

Hi - this is taken from the Haynes manual - I've used these checks in the past:

1. Connect a voltmeter across the supply wire terminals and operate starter motor briefly - should see >=11.5 volts.
2. Connect an Ohmeter across the regulator heater element (regulator itself) - you should see between 16 and 22ohms.

As for cleaning it - not sure on that one - think they may be sealed units -someone else on here may have an idea.

Funny thing is my car does the same at the moment - but after about 10min it's OK - and it passes these tests!

Good luck!

Resistance check of the heating element is a basic test of the WUR. A more sophisticated check involves a fuel pressure gauge, but it will 100% diagnose a WUR fault, if so affected. Don't forget also to check/set the mixture, which can give similar symptoms if not set properly, even if the WUR is fine in itself.

Thanks for the reply guys!!!!

1. I got resistance of 18 at the WUR but zero voltage when connecting to the wire side with the ignition switched on? What would be the next step from here? I'm assuming its either the connection to the rubber plug (are these still available?) Or the connection at the other side wherever that may be??

2. Paul - Is there an easy way to check / set the mixture or is it a job for someone a bit more experienced?!?!? (I'm in Stoke)

Cheers lads
Mike

There is no easy way, no shortcuts to getting it accurately measured. You can buy a gas analyser from Halfords but they're around ?100; or you can take it to a garage who will have more sophisticated, accurate gear.

…and more importantly they'll (hopfully) have an idea how to use the thing! Ha ha..

Thanks Paul

- Any ideas about the lack of voltage to the wires at the WUR?