WUR Adjustment Plug

por73911 · 09-10-2006, 07:41 AM

Guys, I have been searching posts for a couple of days and have not seen the WUR "PLUG" the everybody is talking about in thier posts. Is it the black circle that the fuel line is attachached or is it somewhere else? My WUR is the second from the left...Thanks Paul

por73911 · 09-10-2006, 08:07 AM

Well I guess I gave up on my search to soon! I found it!

john walker's workshop · 09-10-2006, 08:12 AM

a lot of people mess with those plugs when the problem is something else, and end up screwing up an expensive part. do a price check on one.

por73911 · 11:00 AM

When I started have running problem I went straight to the "CIS" posts. Read and reread and the first thing I got out of the post was "don't jump the gun and blame it on the CIS" So I checked everything and I mean everything. Well it turned out that a couple of taps on the WUR "plug" cured my cold start problem. I still have a hot start problem though. I can turn it off and it will start right back up but if I leave it off for a few minutes (10 or more) it will not start unless I use starting fluid. But once it is cold again it will start right up. I was thinking Accumaltor(sp) but I do not want to throw 125.00 at a guess. Any Ideas?

ianc · 09-10-2006, 11:08 AM

Por,

Buy the CIS pressure gauges for a lot less than $125 and diagnose it properly. Tapping on the plug is not accurate (particularly if you don't have the gauges to see the results of your work) and can cause further troubles. The best thing to do is modify the WUR to be adjustable like this:

Modified my WUR

Then hook up your gauges and test. With the screw installed in the plug, you can get it set exactly where it should be. You can even adjust it for winter and summer if you like.

Pressure tests will also let you know if your accumulator or fuel pump check valve are the culprit by looking for residual pressure after a shutdown. Stop guessing and start diagnosing.

ianc

ruf-porsche · ruf-porsche's Garage

Quote:

Originally posted by por73911
When I started have running problem I went straight to the "CIS" posts. Read and reread and the first thing I got out of the post was "don't jump the gun and blame it on the CIS" So I checked everything and I mean everything. Well it turned out that a couple of taps on the WUR "plug" cured my cold start problem. I still have a hot start problem though. I can turn it off and it will start right back up but if I leave it off for a few minutes (10 or more) it will not start unless I use starting fluid. But once it is cold again it will start right up. I was thinking Accumaltor(sp) but I do not want to throw 125.00 at a guess. Any Ideas?

Residual pressure not holding.

john walker's workshop · 09-10-2006, 12:50 PM

add or replace the fuel pump check valve first, then if that doesn't allow the system to hold 1.6bar for at least 20 minutes, then the accumulator will most likely fix it. it can be either, or both. if you use the proper CIS gauges, then you can see if the pressure holds. if you don't have gauges, a very gentle lift under the sensor plate will tell you if there is pressure remaining after 20 minutes. no pressure will be obvious.

Johnathan · 09-10-2006, 03:54 PM

Just got finished adjusting my WUR, thankfully the previous owner had gone through the trouble of drilling and tapping the WUR. Turns out my System pressure was perfect. But the cold and warm control pressures were way too low (about 25psi to low).. couple adjustments on the WUR and it's all back into spec....but, the only way to know this is if you get the CIS guages, very worthy investment...

por73911 · 10-07-2006, 05:55 AM

Ok I got my gauges and I have 5 Bar between my WUR and FD. The car is running great but will not start with out my lifting the air plate and putting fuel in the cylinders. The cold start valves is working correctly but it will not ever start with out lifting the plate. I would adjust the plate with the idle screw but it is already idling at 1500 and I would not want it any higher (would like lower if I can ever get it right). I have discovered I do not have ANY check valve so I need to get that straightened out also. Any ideas or tests I need to do on the starting problem? I know a check valve will help with hot start but what about cold start? Thanks Paul

Johnathan · 10-07-2006, 06:26 AM

It sounds like you are measuring the System Pressure (5bar is within spec for my SC). There should be a valve on the guage that you can turn to allow fuel to flow into the WUR, thus giving you the control presure, and allowing the car to start.

oneblueyedog · oneblueyedog's Garage

When testing the cold pressure and setting it, I once forgot to pull a slight vacuum on the WUR as it states in the handbook. It makes a difference on the gauge bigtime. It's only enough pressure that the vacuum of the engine would supply to the port. It's the manifold port on the bottom of my WUR.

Hope this helps.