WUR plug has power but...

[Funracer]

Jumpered the fuel pump relay, ignition on to run pump. Let it run for 10 minutes with WUR plugged in. My laser thermometer reading pointed at the WUR went from 80.7F (ambient) to 82.9F during that time, just over 2F increase. The WUR does not feel warm to the touch.

WUR plug measures 11.7 VDC across the two contacts. WUR resistance prior to the start of the test was 26 ohms

I know the WUR is supposed to be heated electrically. Is it supposed to get warm or hot to the touch prior to engine heat warming it up? Or is it heating up inside the WUR but you cant tell from outside?

It would appear I have power to the WUR plug but it is not heating up the WUR electrically.

WUR is a -090

Thanks

[RarlyL8]

The part that heats up is a bi-metallic strip inside of the WUR, the body itself does not heat up. You can read more about how these components function here:
Porche Enthusiasts Page

[Funracer]

Originally Posted by RarlyL8

The part that heats up is a bi-metallic strip inside of the WUR, the body itself does not heat up. You can read more about how these components function here:
Porche Enthusiasts Page

Yes I agree. But if some of the heat to the bi-metallic strip transferred to the WUR body and you could feel it or read it on a thermometer then you would at least know the strip is heating and therefor having an effect on control pressures before the engine heat does the same thing a few minutes later. Or in my case, not heating.

Btw, once I sort this WUR thing out once and for all I will be calling you for a new exhaust system. But I am not spending another penny on this lovely machine until it runs like it is supposed to.

Regards

[RarlyL8]

What issues is the engine having?
Heat transferred to the WUR body would be a possible go-no go test but wouldn't tell you much beyond that. Best to get fuel pressure measurements and time the warm up phase from bone cold until spec warm fuel pressure is reached. Yes absolutely best to get the engine running properly before doing any performance modifications.

[AndrewCologne]

The heat within the WUR (means of the heating element of the bimetallic strip) is that small that it won't reach that much the WURs case. The heating element gives the bimetallic strip the specific heat where the whole device will be heaten by the engine finally anyway.

So the only approach to see if the heating element and therefore the bimetallic strip function is working properly, is to make a fuel control pressure test while the warming up of the heating element is processing via jumper fuel pump relay and therefore 12v connected.