2.9?

This is the post I was referring to:

http://forums.pelicanparts.com/showthread.php?s=&threadid=178902&highlight=WUR+ad justment

Gunter,

The previous owners of my car were a creative bunch. When the WUR failed to warm up they knocked the plug out to increase warm pressure, then they adjusted the mixture to compensate. I knocked the plug back in so my cold control was within spec 2.25. Then I fixed the power supply to the relay, and Voila, warm pressure=2.9, which is in spec according to my factory manuals. Then I had to play with the mixture to get it back in reasonable condition. Now all I need is a CO tester to get it right on.

BTW: searching for more CIS info I found this Bosch CIS book online, is this one you were referring to?

http://www.phat-gti.com/downloads/boschtech-12d.pdf

Are you sure?????
 

I just checked the wiring diagram for the CSV and TTS. The wiring diagram says otherwise. Could someone knowledgeable in electrical wiring explain the discrepancies about T77911S's and my assumption. Learning new things everyday.....Thanks.

Tony

Excellent link, Donnie! Thanks!

Brian

boyt911sc,
the way the drawing shows it, the "heater" part of the TTS is in parallel with the "switch" portion of the TTS which is in series with the CSV. (did i just confuse the heck out of ya or what).
power is constant to the "heater" side. the "switch" portion applies a ground for the CSV when cold to allow it to operate. once hot, the ground is removed to turn off the CSV. if u are still uncertain about this, let me know what it is.

Cleaning WUR and takigng apart
 

I checked out a few more parts of the CIS system. I'm getting closer. Things like the Auxiliary air Reg are working fine, etc. I plan on checking the injectors for good spray too. They just pop out right? Only o-ring holding them in. Probably should have fresh orings to replace them when I pull them? Even though WUR pres numbers are good I wanted to check internal screen as Gunter suggested. Where exactly is it and do I have to remove WUR to do it?
Incase anybody wants to ponder symptoms more this is what they are.
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Starts fine when cranking (cold start valve is good). Stalls. Does this about three times then idles nicely. While cold if you push gas pedal it pops and then stalls. When warm everything runs great. I assume poping means that it is going lean when you hit pedal. So basically there is some fuel correction for the increased air flow that is not happening.
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Have looked over a few of the sites and threads that you guys suggested and didn't see an exact match for these symptoms. For the ones that were lose they just seem to list a bunch of parts to check. Not exactly specific to my case.
Looked over that WUR adjustment trick but since I have good warm conditions I don't want to do it yet. It also seems to me that it may just be a cover up for real problem.
Thanks,
Adam

Have you verified the timing?

Out of curriosity, unplug the wur electric and try it, see if it still does it with a warm engine, but cold wur.

Have you checked the airflow sensor plate to make sure it is not "gummed up".

The screen is on the inlet side of the wur, removal would be required, then remove the nipple for the fuel inlet. The screen is right there, flush with carb cleaner, or gas.

Injectors pop out, use a 15mm against the bung and a 12mm to pry against that.

Seems you may just be a little lean, have you set the mixture to the correct CO level while warm?

Re: Cleaning WUR and takigng apart
 

The WUR can stay mounted but, it's easier to work on when taken out.
If you want to disconnect the electric plug, watch that small wire-clip.
Carefully remove the line on top of the WUR. (For the line with the cap-nut counter-hold the fitting with another wrench).
Check the small screen for debris.

It's easier to pull out the injectors if you spray a little WD-40 on the O-rings first; pry straight up with the help of a wrench fitting under the cap-nut.
You can do them single, or you can use 6 clear glass bottles and observe them one by one.
Ignition on, lift the air flow sensor plate.
Have a fire extinguisher handy!

Should I have new injector orings ready for replacment? Do you need to remove the injector seat ( using special tool) to change o-rings?
Adam

Not a bad idea to have some (so why not have 6) new O rings in case some of them look cracked.

I like to have at least one of the phenolic inserts and its own, different, O ring, on hand, too. Just in case one of these comes out with the injector and gets damaged. They are held in by staking the aluminum around the hole - you can see how that is done before you start.

Walt

Thanks Walt. The book also says to remove the line from the injector. The line is pretty flexable. Is it really necessary, i.e. are you likely to damage line?

adam:
To test the injectors, or to replace the O-rings. you don't need to remove the line.
The old O-rings give you enough play to pull the injectors straight out after you spray some WD-40 on the O-rings.
After you finish testing, replace the old O-rings with new ones, then smear some Vaseline on the new O-rings and pop the injectors back in.
However, you can remove all injectors and soak them for 1-2 days in a small can of injector cleaner to clean the small screen inside the injectors, then blow out with air.
The inserts are usually not damaged, you'll have to see.
Replacing the inserts is a different kettle of fish; much more work.
To prevent any debris from falling into the heads, and to make it easier to work, you need to remove the intake runners meaning:
Loosen the clamps around the rubber boots on the runners, remove the 2 nuts on the intake flanges, remove each intake runner, check the condition of the gasket between runner and head; these gaskets are one place where vacuum leaks occur.
If you plan on replacing the inserts, you might as well get a set of new gaskets. If the inserts are good, check the torque of the nuts on the studs for the runners; you'll need a 13?mm swivel-head socket with a large extension for that. Check the condition of the rubber boots on the runners.

Gunter is a far more meticulous mechanic than I.

I would never remove the runners just to pull injectors. That is a bear of a job with the engine in the car, some nuts are hard to get to, and some of the hose clamps probably were installed with the engine on a rotating stand and are at orientations nearly impossible to get a screw driver into their slot.

But on rereading his post I see that he is referring to replacing the inserts. That is, indeed, a different kettle of fish. I am trying to remember if I have ever removed one that didn't come out on its own by accident. I don't think so.

I recently replaced my O rings because I had noticed some looked cracked. Turns out they weren't that bad, but I did it anyway. While, thankfully, the plastic insulator pieces stayed put, I have had some come out on me. Hence my desire to have a spare or two on hand, lest a short job end up with the car laid up for several days awaiting a part. Sometimes the insulators that decide to come out can be reinstalled, but sometimes they break along the way.

My first 911 engine was a '77 2.7. Those had a plastic injector line, quite flexible. So I was hesitant about this with my 3.0 with the nice steel lines. But it is no problem to flex them to the side after loosening the nut holding them to the injector. Or even poping them out far enough that the seal is above its notch before removing the line.

Walt

I took apart the WUR last night. Lower diaphram is fine ( holding suction). Upper chamber was not holding vacuum very well. Is there anywhere I can get the o-ring that seals the two case halfs?
Other note: Heating element green insulation was cracked with big chunks falling off. I doubt that makes any difference especially since it seems to be behaving normally.
Adam,

x2. I also took my WUR apart last night and noticed a small section of the seal that is slightly corroded which would obviously cause a leak. If the o-ring is difficult/impossible to get, would something else suffice?

i tried to get you to check the vacuum 2 pages ago. the vacuum from the engine is connected to the top chamber. with the engine running, it should bring the pressure into the 3.4-3.8 range. if your top chamber is leaking, that is why your pressure is low. i will have to look at my old WUR again, but you could be leaking between the middle section and the diaphragm. creating air leaks is why i dont encourage anyone to open their WUR, unless they know it is the problem. the 1.2 will also be higher with vacuum, unless the TTV is not working. you may try silicon on the seal if u cant find a new one.
have u checked the TTV to make sure it is not leaking, if u have one?

i hope these numbers will help
my specs on a 3 yr old WUR:
cold no vac- .8bar
cold with vac- 1.8bar
warm with no vac- 2.9bar
warm with vac- 3.6bar

I did check the vac before busting it open and that is where I discovered it leaked. I guess I will have to grab an o-ring kit and make one for it. I had another question. The vac line that goes to the bottom of the diaphram. I would assume that this is just referencing atmosphere press. The line goes to a small flat round device that has a second hose coming out of it and an electrical connector. Haven't looked it up yet or what it goes too. Anybody have info on it

Yes, per this image, #9 is atmosphere - slightly different in the 78, but the principle is the same.

How are you going to make one with an O-Ring kit? won't you have a gap?

http://forums.pelicanparts.com/uploa...1093387343.gif

Oring kits are spools of O-ring material (different diameters) with a special glue that can be used to make a closed ring. They work very well.

So what is that little puck thing with the electronic plug that the atmosphere reference (#9) goes too?