WUR033, adjustment?

[AndreasK]

Trying to fix a cold running issue. Warm running is good.

My cold control pressure is low. 0,75 at 10 C (Spec 1.1 to 1.6)System and warm control pressures within spec, but at the low end.

Ideally I´d send my WUR for a rebuild, but living in Northern Norway complicates things.

Am I correct in assuming, opening the WUR (I´we done it before for cleaning) tapping the plunger for the Bi-metallic strip out a tiny bit, could be my solution for a DIY fix? Is there ANY way to say, roughly, how much I should tap it out?

[AndrewCologne]

https://nineelevenheaven.wordpress.com/adjusting-the-warm-up-regulator/

Adjustment explained in the link should work with your type of WUR as well

[AndreasK]

Originally Posted by AndrewCologne

https://nineelevenheaven.wordpress.com/adjusting-the-warm-up-regulator/

Adjustment explained in the link should work with your type of WUR as well

Thanks! Haven´t given how to adjust to much thought, but I did visualize tapping with a hammer to be somewhat upresise Using a wise is far better!

Now to figure out how much to adjust, to avoid having to go to many times back and forth

[gwmac]

I did this
Made an Adjustable WUR- Step by step, got Pics!

[ahh911]

Here is how I knock it down in steps of 0.02mm, which makes a noticeable difference in operation. The thickness of the feeler gauges that I cut and fit on the top of the wur pin is the resolution. I then hammer it down. It is very very accurate and repeatable, I just add the next feeler gauge up in size to achieve the desired depth.


Post 27.

https://forums.pelicanparts.com/porsche-911-technical-forum/1118039-wur-ohm-reading-0-00-a-2.html

Phil

[pmax]

Here's what I did which should work for you since the 77 has the flexible fuel lines just like my 80. Not sure those with the later CIS with metal lines can do the same.

Undo the two allen bolts, keep the fuel lines connected.

Use a C-clamp with blocks of wood and an inverted short bolt whose head fits on the pin.

Monitor the FP as you turn in small increments. Not much movement is needed to affect the FP.

[ahh911]

Originally Posted by pmax

Here's what I did which should work for you since the 77 has the flexible fuel lines just like my 80.

Undo the two allen bolts, keep the fuel lines connected.

Use a C-clamp with blocks of wood and an inverted short bolt whose head fits on the pin.

Monitor the FP as you turn in small increments. Not much movement is needed to affect the FP.

I have my doubts that using a C clamp on it's own can achieve the small changes required as for me I would find it nearly impossible to know if the pin has moved at all and by how much, but monitoring the fuel pressure while performing is a very good suggestion that overcomes this.

The 81 911 has hard lines but the wur to distributor line has a flexible section and can be moved easily. The wur return line moves around too but maybe not enough? Maybe I'll try it out next time.

[pmax]

Originally Posted by ahh911

I'm surprised a C clamp can get the small movements required, monitoring the fuel pressure while performing is a good suggestion. 81 with hard lines, the wur to distributor line has a flexible section and can be moved easily. The wur return line moves around too but maybe not enough? Maybe I'll try it out next time.

The helical to linear action works great.

Yeah, I wouldn't wanna risk damaging the hard line trying to fit a big clamp and the block of wood or padding under the WUR but a small "vise" might work I suppose.

[ahh911]

pmax,

worst case is one would need a flexible extension from the wur outlet to the return line to allow the wur to move about freely.

Phil