Can the WUR be adjusted on a 3.0?

[jedwards1123]

Hi All,
My ’83 Euro 3.0 SC Cab has a very enthusiastic Warm Up Regulator (WUR). It starts beautifully, but after about 30 seconds, the WUR jumps in and pushes revs up to around 1,800 rpm and holds it there for quite some time, before slowly allowing it to drop, once it is well and truly warmed up. Seems far more than is necessary to get the car running in the morning.

As the temperature here in Western Australia is not giving to drop below 20 degree C for the next 5 months, can I “calm it down” a bit by adjustment or even disable the WUR until the weather turns cold again around mid next year?

cheers
Jeff

[James Brown]

Oh yes in fact there are instructions in here to make it a adjustable WUR. Do a search for that.

[pete3799]

You'll want to check your fuel pressures before doing anything to the WUR.

[prschmn]

Are you sure it's not the aux air valve you need to be checking?

[boyt911sc]

jedwards,

The 20°C (68°F) weather is a very comfortable late spring/early summer temperature (downunder). It would be really nice to drive around and enjoy your car at this time of the year. The Bosch WUR's have been successfully made adjustable by many DIYer's with very good results. Before you attempt to work on your WUR, do yourself a favor by checking the control pressures (cold/warm). There is a great probability it is not the culprit of your problem. Have you also checked the AAR's operation? Keep us posted.

Tony

[stlrj]

What you are describing is the function or malfunction of the aux air regulator.

[Gunter]

Check the AAR located on the right side of the engine between 5-6 intake runner.
It's the item that has a small electric plug and a large vacuum hose connected to it.
Open the clamp holding the outside-hose.
Pry it off with the screwdriver just enough to get it out of the way so you can see into the opening.
Don’t worry about the Alu pipe; it’ll move enough.
With the help of a small mirror and a light, peek inside the AAR.
When COLD, you should see an opening in the slide shaped like a half-moon.
Re-connect the hose, start the engine and let it get real hot.
Stop engine, remove the vac hose again, check the opening again.
When HOT, the opening should be completely closed.
If it isn't closed, the AAR is either kaput or doesn't get any power.
You can spray some WD-40 into the valve in case it is just sticky.
To check the power, carefully open the tiny clip on the plug with a very small screwdriver and pull it off.
The wire clip is tricky but necessary; don't yank it off.
Start the engine and check the plug for 12 V.
Just ignition ON will not get power to AAR or WUR; engine has to run.
(One wire is power, the other (brown) is ground)
With power to the AAR, it should close after about 5 minutes.
If all is well, replace the hose and clamp securely.
Let us know if the AAR works HOT and COLD.

If the AAR works correctly, go on to check the fuel pressures as described in the Bentley SC Repair Manual. If you don't have one, get it.

If you still want to make the WUR adjustable, it can be done by removing it and doing some drilling and tapping for an adjustment screw.

More later. Do the above first.

[T77911S]

if the CCP if not right, the bad mixture could be keeping the RPM's down for that first 30 seconds, then as the WUR warms up, the mixture gets better and the RPM's rise from the AAR.

check control pressures.

[boyt911sc]

Originally Posted by Gunter

Check the AAR located on the right side of the engine between 5-6 intake runner.
It's the item that has a small electric plug and a large vacuum hose connected to it.
Open the clamp holding the outside-hose.
Pry it off with the screwdriver just enough to get it out of the way so you can see into the opening.
Don’t worry about the Alu pipe; it’ll move enough.
With the help of a small mirror and a light, peek inside the AAR.
When COLD, you should see an opening in the slide shaped like a half-moon.
Re-connect the hose, start the engine and let it get real hot.
Stop engine, remove the vac hose again, check the opening again.
When HOT, the opening should be completely closed.
If it isn't closed, the AAR is either kaput or doesn't get any power.
You can spray some WD-40 into the valve in case it is just sticky.
To check the power, carefully open the tiny clip on the plug with a very small screwdriver and pull it off.
The wire clip is tricky but necessary; don't yank it off.
Start the engine and check the plug for 12 V.
Just ignition ON will not get power to AAR or WUR; engine has to run.
(One wire is power, the other (brown) is ground)
With power to the AAR, it should close after about 5 minutes.
If all is well, replace the hose and clamp securely.
Let us know if the AAR works HOT and COLD.

If the AAR works correctly, go on to check the fuel pressures as described in the Bentley SC Repair Manual. If you don't have one, get it.

If you still want to make the WUR adjustable, it can be done by removing it and doing some drilling and tapping for an adjustment screw.

More later. Do the above first.

Jeff,

Gunter has given you a very detail instruction to follow for checking an AAR. If I may add something, I have a different method in checking an AAR installed in the car. Instead of running the engine to keep it warm, simply run the FP like doing a FP test.

When you connect 87a-30 terminals (FP relay socket) with the ignition @ ON position, the following CIS components, FP, AAR, WUR, FV & TTV (optional), connected to #30 will be energized. Also consider checking the heater resistance (Ohms). It will close between 3 to 5 minutes depending on your heater's resistance value. Keep us posted.

Tony