LJ,

Yes, I did that. I was able to get the large plug knocked down, which raised the wcp to 2.4 bar. Even a 10 minute warming up period, connected and on the manifold, still only raised the wcp by .5 bar.

I have just spoken to a well respected P-car tuner here in TO, Jack Chehanian @ gtek auto. He suggested checking the elec connection, which I will do again, the return line to the fd, and the filter @ the top of the WUR.

He can do a smoke test for me, but said that vacuum wouldn't be the cause of the WUR not rising. The return line was replaced by me a couple of years ago, and the filter should have been checked when the WUR was rebuilt, but I'll recheck.

ossiblue, you may be on to something here. You adjust the "warm pressure" by moving the diaphragm up and down, then adjust the cold pressure by adjusting the pin up and down. Here's an awesome post by stevemfr that describes how to adjust it:

http://forums.pelicanparts.com/3891039-post24.html

I used it to set mine, and it works, on the money, now.

BTW, I found that post regarding pressure testing the airbox:

http://forums.pelicanparts.com/porsche-911-technical-forum/367288-cis-problem-tested-have-results-opinions-2.html

[/URL]

jonbot,

See above post by me. I've already followed stevenmfr's procedure and got the results I previously posted. 1.3 cold, 2.4 warm. I'm a little afraid to knock the large plug in farther as it is almost flush w/ the top of the housing, but I may have to.

I'll recheck the electrical connections, filter and line.

I'm wondering if there is somethiong wrong internally to prevent the cps from rising.

you had a 1 bar change here.
you may have to raise the CCP pin to get it out of the way and set the WCP first.
on my bad 033 WUR, i cant see the spring bend, it gets hot, but no bend, that may be what is happening to yours. i have never looked at a good one to see how much it bends. it may not be much, a mm or 2 maybe?

Hi Paul,
I was out of town a few days and missed all the excitement!

I'm a little pressed for time right now, so I couldn't read the entire thread - forgive me if I repeat anything (what a great bunch of guys - so much info in a week!).

First, CIS really is relatively simple and robust. Your car can be made to run with just about any WUR providing everything else is tight and right.

A couple of things about the control pressure: I assume Porsche_Monkey is right. You don't need to go lower than the pressure given at 10degC - although I do have to admit that I've never checked CP in sub zero weather. Maybe the bi-metal strip continues bending in the other direction with increasing cold and Porsche just gave those specs because that's where most shops are going to be when they set the CP. Every bi-metal I've had in hand has been straight cold, and curved warm. Interesting question - although I am going to assume that under 10degC the pressure drop (bending of the bi-metal) is no longer linear.

While it is necessary to get the control pressure in-the-ballpark, being off a little one way or another will not make the motor run as poorly as you say. And if you can get the pressure to rise by tapping the diaphragm disk down, it will prob. be fine. Check the bi-metal and heater - the easiest would be to hook the heater up to 12v with the bottom off the WUR and watching the bi-metal bend. After that you reassemble the WUR and reset the pressures. If this were me, I'd leave oof all vac lines off and reset the WUR bare-bones. You won't have full throttle enrichment or leaning on decel, etc. but you'll have eliminated silly variables. And your motor will run w/o all that. Once it's running properly, you can hook everything back up.

I do believe that Milt and the others are right and you have a vac prob (possibly that someone tried to compensate with the CIS settings rather than fixing properly. If this were me (after all you've been through), I'd yank the entire CIS system off the motor. A 13mm-universal-joint socket and an assortment of 3/8" extensions, and you should have the CIS out in under an hour even as a complete novice (unless you have the stature of Hulk-Hogan:eek::rolleyes:). You can then inspect all components on the bench - much easier. Disassemble, inspect, clean (, repair) and you should be good to go. Once you're back in the car, check the injectors for spray pattern and flow (and use new o-rings when re-installing. Reset the CP's and theoretically, you're good to go. (when you're resetting the CP's, close the valve on the gauge at regular intervals and make sure your system pressure remains constant.

It needs to bend enough to get back to warm press - at which point th bi-metal is just hanging around in mid-air doing nothing.

Wow - been feeling sh@#*ty all day and now the wife just came in and took my temp: got 40.2degC. Off to bed to set my warm press:rolleyes:

uh - hit over 300! gotta get my 911 to do that in kmh's.

sorry, I might be delerious...

Thanks stevemfr.

My latest attempt was going to be what both Ty and you mentioned. I'm thinking that @ first, when I got a 1 bar difference there was that amount of bend in the bar. Later, when I knocked the wcp plug maybe I induced too much bend into it. Then when I knocked the wcp plug maybe I bent it even more. I'm going to have to do some research. I think I remember a thread where someone bent their bar to get the right CPs. I also remember one where someone shortened the pin.

Take care of yourself.

EDIT: Part of above is incorrect. The bend of the arm is not changed while knocking the plugs since the pin slides through it, unless it has been pushed to the extreme lower end of its travel @ the spring end.

So does the bar straighten or bend up when heated or does it go down?It seems like it should go upward putting pressure on the diaphragm @ the top and lowering the wcp. The vac enrichment on WOT would then suck the pin/diaphragm back down to enrich.http://forums.pelicanparts.com/uploa...1239050905.jpg

the bi-metal strip bends upwards, the spring pushes the rod in the cup upwards more and increases pressure - just as you said. This is why you first need to adjust warm press by smacking the diaphragm-disk down (at this point the bi metal should be up in th air). Then th cold press is adjusted by smacking the pin that holds the bi metal down till it pushes the spring down far enough to drop the press to where you want it.
sorry if this is incoherent... g'nightSmileWavy

Not incoherent @ all.

I'm going to have to open it up, check my bend and the relationship of all elements. Thank you.

If the bar isn't bending or bending enough, I supposed that could be due to either 1. too much bend to begin with 2. not enough "juice" to get it hot, either via low voltage or a blown heat element.

In my case I think I don't have enough bend. When I had the cold plug down, the .3 bar setting pushed the pin down giving a low pressure that then rose by 1 bar to 1.3. When I pulled the cold plug up to 1.3 bar it took pressure off the diaphragm so there was no initial pressure so when the bar straightened there was little or no difference.

If someone has a known good one that is opened up and could do a tracing of the profile of the bar and post it, that would be very helpful. BTW I'm not anticipating anyone doing this. I just thought I'd ask!

Just checking >>>
Knocking the small plug down lowers pressure.
Knocking the large plug down raises pressure.

Any idea of how much movement = 1 bar ?

Does the WUR always have 12 Volts to it when key is on ?

Wur.......
 

Wyvern,

Since your car is a '75 (if I remember correctly), the WUR will get power from the ignition switch after the motor starts to run. The generator (alternator) energizes the WUR relay and power from ignition switch is supplied to the WUR. However, your FP will run as soon as you turn the ignition switch to ON position.

Tony

paul,
that is not a pic of your WUR if yours has the vac port.

the strip has a hole in the middle that the pin goes through, the strip does not push the pin up.
the strip applies counter pressure to the spring, pushing it down to lower the CCP. this is done by how far the pin it is bolted to is pushed down. when heated, the strip bends up removing pressure from the spring and raising the WCP. if the CCP pin is pushed too far down, the strip is still effecting the spring and the WCP. if the pin is too high, there will be no change in CCP to WCP. if the strip loses its ability to bend up (bad WUR) you will not have a change in CP.
make sure the CCP pin is hi enough so it has no effect when setting WCP.

steve. how did the thermometer taste, did ya have to roll over?

:eek:
Nooooo - thank god these days they have those ear thermometers - although, come to think of it, maybe I'll have to arrange for the batteries to be dead the next time the wife is sick. That way I can get her to roll over :D

See above.

Ty,

I understand that. The spring pushes the pin upward and the bimetal arm pushes the spring down, until it releases as the temps rise. Also, you're correct--my vac enriched WUR has the lower chamber. I was just using a pic I got from Gunter to show the relationship of the plugs and arm.

My next step, probably wed or thurs, will be to raise the ccp plug to get it free floating, and see how high my wcp goes. Then I'll lower the ccp plug to spec and see what happens. If that doesn't do it, then I'll have to open it and see why the arm isn't bending correctly.

You Devil! ;)

BTW you may be right about the vac leak. I haven't ruled it out yet. I'm just trying to get the WUR working first.

If you suspect the heater element can't you test it with an ohm meter? My guess is that a blown heater element would cause over rich condition.

Check it with an ammeter. You need to measure the current, to verify you have voltage and the right resistance.