Pigbladder, I've arranged to borrow a fuel pressure gauge so will report back on my findings next week when I've had a tinker. I expect my car will be set up correctly in terms of pressures and CO when at hot idle as I've not really altered anything since Stealth had it. I'm starting to think my cold starting/rough idling will be down to a knackered WUR but I may still be wrong, was convinced it was the accumulator the other week and it wasn't! Edited by: Stu
cheers, ive taken readings from cold every 15 secs for the wur..we can compare when you do yours gti is going to check his too
Yep - sounds like a good plan. From doing some reading it looks like you should get a very smooth transition in control pressure (regulated by the WUR of course) as the car goes through the warm-up period - I suspect on mine this definitely isn't happening.
Mate, if your control pressure is accurate then bending the bi-metalic strip wont achieve anything. Anyway if you want to see if it makes any difference just unplug it, it'll have the same effect. Do you still run the over-run bypass valve on the airbox?
yeah ive got all that junk on the airbox..dunno how to check any of it about the wur..ive set it to 48 when hot and observed a steady increase in pressure, but how can i confirm/ajust the cold setting.. im sure a tad richer from cold would sort me out
HiPigbladder, You can adjust the pressure by drifting the spiggot in or out, see the pics below:- The spiggot is the one with the nut on from the inside and from the outside the drift point is near the 367 number On the 16V WUR and the 5 cylinder Audi ones there is an additional adjustment screw so that you can set the cold pressure by drifting the spiggot and the hot pressure with the screw. I have set several 16V WURs up like this so that they are correct for the 8V.
afaik pig has alreay adjusted his wur via the spiggot as i went through this with him a couple of weeks back. i think its something to do with the electrics to the bimetallic strip, as although his does rise during warm up, it doesn't rise fast enough - which is what you'd imagine failed electrics would cause. here's our figures (taken every 15 seconds from cold): pig gti 10 18 9  ;34 11 38 15 42 19 46 24 48 28 31 35 38 41 43 46 48 obviously, the initial readings don't necessarily match in time as it takes a few seconds to get from turning the key to taking the first reading, but you can see they're totally different. Edited by: GTI
The electrics on the bi-metallic strip is just a resistor that has 12 Volt s put across it all the time the engine is running. Pigs WUR steps far too quickly, when I have seen this before it has been caused by dirt in the inlet and outlet gauzes and dirt on the metal disk that is the pressure regulator (this can be split and cleaned easily). The WUR should have cold control pressures of (PSI and degrees C) 16 at 50 24 at 75 32 at 100 and when fully warm 49 to 55 PSI
this spigot ajusting is new to me id ajusted the warm setting under the "secret" cap but not the cold idle thanks for the info 150pdgti what way do i bash for richer?
the spiggot IS the thing under the 'secret' cap, except on a 16v it has an allen key built into it so that is doesn't need bashing to adjust it. pd150, how can you say his goes too fast, when mine runs perfectly at all temperatures and rises even faster? his is too slow surely?! this is why i suspect the electrics to the bimetallic strip. if it wasn't getting 12v in the way it should then the strip won't heat up as fast and the control pressure will take longer to rise.
Sorry GTI, you are correct, for some reason (beer !!) I read your readings as pigs and vice versa !! Yes pigs WUR appears to be too slow - is the resistor in the WUR open circuit ? When 12 Volts is put across it does it get warm ? AFAIK all the WURs can have the cold pressure set by moving the spiggot position, drifting inwards reduces the "static" control pressure at cold. The hot running pressure is set by the distance the bi-metal strip moves, it moves becasue of the resistor warming up, engine heat and the loading placed on it by the spring plate. It was my understanding that on the 16V WURs you can change the hot pressure by the adjustment screw. It has been a while since I had a 16V WUR apart - so has my memory let me down :-)
I don't know where you're reading that from but those figures are PSI and Fahrenheit The spiggot (post the bi-metalic spring mounts to) is not the same as the allen key under the brass cap. By adjusting the bi-metalic spring mounting you are adjusting the warm up fuel enrichment by adjusting the allen key under the cap you are adjusting control pressure load/altitude enrichment.
thanks guys.i think i still understand thats some handy info thank you k jet isnt rocket science when you look into it
any ideas for a cheap way of knowing my engine temp? so drifiting inwards reduces static control pressure..and that would be richer ? right?
