What is correct method for testing warm pressure - with vacuum port

[Tidybuoy]

So far, the only literature I have found says that the warm pressure on my #033 wur should be 3.2@40 & 3.6@40 vacuum connection.

Can someone tell me the exact testing procedure - specifically the part involving vacuum? I originally tested with vacuum plugged in and also unplugged and did not see any difference. Now I'm thinking that I am supposed to pump vacuum to the side port on the wur. I also have no idea if I am supposed to do something to the top port. I also do not know what pressure I would pump the vacuum too, if that is the procedure.

Any advice would be appreciated..........Thanks!

[Bob Kontak]

This link has a diagram of the 033 regulator.

WUR question (are they full of ... ?)

The test is performed when warm. It does not state to disconnect anything aside from putting the vacuum pump on the vacuum port. Testing vacuum/pressure is stated on the top.

Here is a converter to help with the units of measure on your pump.

vacuum pressure unit conversion

That's all I got.

Did the 74 have the 033 regulator?

[Tidybuoy]

Originally Posted by Bob Kontak

Did the 74 have the 033 regulator?

No it did not. The prior owner, who built this engine, built to 911S spec, used an #033 wur and '79 fuel distributor/air sensor meter. The car ran perfect when I got it many years ago so I believe this combo works. He stated '76 CIS however, it still has the throttle lever between the seats and there is no peripherial equipment like aux air valve, etc..

Thanks for the links, I will take a look.

[ossiblue]

Originally Posted by Tidybuoy

So far, the only literature I have found says that the warm pressure on my #033 wur should be 3.2@40 & 3.6@40 vacuum connection.

Can someone tell me the exact testing procedure - specifically the part involving vacuum? I originally tested with vacuum plugged in and also unplugged and did not see any difference. Now I'm thinking that I am supposed to pump vacuum to the side port on the wur. I also have no idea if I am supposed to do something to the top port. I also do not know what pressure I would pump the vacuum too, if that is the procedure.

Any advice would be appreciated..........Thanks!

If you tested your wur without the engine running, then you would not see any difference between the plugged and unplugged vacuum connection because the vacuum is created by the intake of a running engine.

The vacuum line is the one on the top of the wur. The lower port is for ambient pressure and is connected to the air filter, not vacuum. If you use the links Bob supplied, you will find the vacuum to apply to the top port, and the pressure that you should get--3.6 bars. Or, you can connect the vacuum port to the throttle body and idle the engine at ~1800 rpm to produce the vacuum and you should get the same reading.

[Tidybuoy]

Thanks Ossiblue! You've been a tremendous help (this post and previous ones).

Now I may need to re-think my vacuum line routing. Currently, the top port on the wur is connected to the top port on the throttle body - the front side, just above the distributor port. The bottom/side port of the wur is T'd into the vacuum line that goes to the top of the deceleration valve. This may be correct routing but I will double check.

I guess this explains why the vacuum line on the top port of the wur had a hose clamp on it - keeping it air tight.

I learn something new every day - I can't wait for the weekend to get this all straightened out.

[Bob Kontak]

Originally Posted by Tidybuoy

This may be correct routing but I will double check.

In the new= CIS primer there is a parts component diagram from the factory manual that should help you confirm.

911 CIS Primer - Parts ID

Good luck.

Agree, ossiblue is great. We are but his minions. :-)

[Tidybuoy]

Originally Posted by Bob Kontak

Agree, ossiblue is great. We are but his minions. :-)

I owe you a big thanks too! And several others on this board.

[Bob Kontak]

Originally Posted by Tidybuoy

I owe you a big thanks too! And several others on this board.

You are welcome but I was not fishing. Without the core group of guys here that cut through the crap, I would still be fiddling with my CIS. It's been happy for a few years now.

All the best!

[Tidybuoy]

Don't worry, I am learning how the CIS works and how to adjust it correctly. Someday soon I will be able to answer questions too.

[javadog]

Originally Posted by Tidybuoy

The bottom/side port of the wur is T'd into the vacuum line that goes to the top of the deceleration valve. This may be correct routing but I will double check.

On a '78, this line goes to the thermo valve. I presume the '79 would be the same. A '74 wouldn't have had this. No idea what your car might have on it...

JR

[Tidybuoy]

Last Question, I think. (I'm trying not to beat a dead horse here).

A mechanic mentioned to me in casual conversation that I need to convert the vacuum requirement based on elevation - is that true? I live at 308 ft above sea level.

Thanks for all the responses and links - they have all been a big help

[javadog]

Nah...

JR

[Tidybuoy]

ok, I figure I'm close to sea level and this might matter if I were way up in the mountains.