I just realized that is a ton of questions in one posting...lol

Sorry about the terminology...i meant o-rings when i said bushings...too early in the morning I guess.

So, update...I adjusted the cold control pressure and the system pressure and got them spot on and the car started up and ran perfect under rev and at idle for about 10 minutes until the car warmed up and then it started to do it's lean backfire thing again with zero throttle control...no rev with a cough and a spit and a little backfire here and there.

I shut off the car and then checked control pressure again and it was about 4 bar so I'm heading back to drill a hole to access the allen screw on the bottom of the WUR.

I'm just not sure what i should seal the hole with once i make it. I'm assuming from watching the WUR video linked from this post that the hole will not let gas out because I think he was adjusting it with the car running.

I'm so excited! It is running better and longer than ever. Thanks to everyone for your help and I'll keep you undated when I get back.

Theres no need to seal it. There is no fuel where you are drilling open. If you find a pic of one (WUR) open, you will see that. Plus, my understanding is that the adjusting screw is mounted on the case anyways. Rjm65 did his last year.

If you are pushing down on the air flow metering plate by hand, you are overriding any effect of control pressure. Like you said, you should see more flow the farther down you push. Higher control pressure basically pushes back up harder on the plate against air flow, so it deflects down less for the same air flow, but this doesn't matter when you are using your hand to push down.

The fact that the fuel flow is falling off as you push farther down means that the WUR has nothing to do with your main problem. Something is wrong with your distributor or possibly fuel delivery by pump. While unlikely, the linkage between the plate and the control rod in the distributor could also be broken. The pressure regulator in the distributor could certainly be part of the problem.

I would start by checking fuel delivery rate with engine off and fuel pump relay jumpered, CIS gauge connected and set to check system pressure (to remove WUR from the loop). You can check fuel delivery at the return line and system pressure at the same time. If this looks good, and the linkage from the plate is properly pushing up on the control rod in the center of the distributor, then you probably have a bad distributor. You may also have a bad WUR, but this is a secondary issue.

There's no fuel there but that compartment is what the second vacuum hose on the WUR ties in to. A small dab of silicone or epoxy after adjustment is made seals it right back up.

Thanks again for all the imput guys. I drilled the hole and set warm control pressure. All pressures are perfect. Cold starts at 1.5 and works its way up to about 3.2 where the top control pressure levels out after warm. The system pressure is 5.2 and the car runs very nice and is able to rev up for about 15 minutes and then once again starts to stumble and slowly (4 to 5 minutes) dies.

I really suspect a vacuum leak that accurs when something opens at temperature.

Once it dies, I can start it right back up and it will go through the same process again only shorter interval from start up to die.

I am going to take the spider off tomorrow and make sure the main throttle body seal is free of leaks. I sprayed carb cleaner toward the front of the throttle body today and noticed a slight surge in the engine.

The other thing i noticed is that when it is running good and I rev it up, it takes longer than it should to return to idle...it kindov floats down slowly.

I'm getting there guys. hearing her run with that throaty growl if only for 15 minutes is worth all the time it's taken so far. I hope to soon put her in gear and see if the transmission works...DOH!

Luis M is correct about the air sensor plate and control pressure. If you initially get fuel to the injectors then it drops off, there is a problem with the system pressure. The air sensor plate is a mechanical link to the control system piston so moving the piston up exposes more of the metering slits which allows more system pressure to feed the injectors.

Might want to look for blockage at the port between the relief valve and fuel distributor body.

K, I can't adjust the warm control pressure through the hole i drilled in the bottom of the WUR. The allen bolt is there and I can turn it, but it has no effect on the control pressure and I think mine is way too high at about 4.5 bar.

I hate throwing parts at this thing and the WUR is a spendy one. Is there someone out there that has a confirmed working one they are willing to send me so I can varify if this is the problem or not? I'll take great care of it and send it back after testing....or will buy it from you at that point if you want to sell.

I'm pretty sure this is where my problem lies.

It seems like your not grasping how this piece works. Here is a link to make your WUR adjustable, rjm65 did this so he could make adjustments from the top of the wur. Sorry the write up has no pics but it does explain how to do it. The post also has the correct pressures you'll need as well.

Porsche 928 Forums dot com - View topic - Making a WUR (Warm Up Regulator) Adjustable

The mods to make the WUR externally adjustable are only for cold control pressure. The allen he's turning on the bottom of the WUR is for adjusting warm control pressure, and somethings up since he says turning it has no effect.

Might as well pop open the WUR at this point, I think someone had previously mentioned this writeup but no link provided :

http://www.landsharkoz.com/images/pdf/wurfix.pdf

turning the screw with care if turned down to low when trying to adjust as theres finicky adjustments to be made by machine really only. its nearly impossible to adjust if gone to low/out. turn it back up just doesnt bring it the other way unfortunately.

make sure all contacts and switch testing for thermotime, cold start valve, idle,. the switches that switch cold/to warm up. carbon isnt clogging any valves, regulators. any gaskets , hoses, orings arent sucking air.

enough fuel cis doesnt like low low fuel tank.

backfire through exhaust? exhaust/gasket air leaks.

Run ok for 15 min even after a hot start makes me think something slow unrelated to temp is happening, like a fuel leak in one of the vacuum control diaphragms.

Make sure the timing is ok under all conditions, good running and bad.

Is the good run time the same if you just let it idle vs run at 2k rpm?

I took the WUR apart today to see what was up with the adjustment screw for warm control. Cold control is exactly where it needs to be.

The diaphragm was stuck to the threads of the screw and the center metal ring would turn with the adjustment...so in short...no adjustment could be made.

The car will idle for about 15 minutes if you leave it alone. If I get in and start revving the engine it sputters and dies quicker than 15 min to answer your question Danglerb and the link Rjm65 sent me said the correct warm control pressure should be 41 to 46 psi. Danglerb and Rjm is right about the externally adjustable modification is only for cold pressure.

I kept a close eye on pressure guage today and saw that the car ran good until the control pressure climbed above 4 bar which is about 58 psi or so and kept climbing up to 4.5 bar (65 psi) and I can't figure out what other component would be allowing pressures that high at operating temperature.

In my silly mind, it has to be the WUR. A leak or anything else...even the distributor would not be creeping the pressure up to operating pressure (which is set on my car at 5.2 bar (75 psi)

Even though I've convinced myself, I still don't want to waste money on a part I don't need...but I guess I should just bite the bullet and rule out the WUR...new (or rebuild on my budget) couldn't hurt in the long run.

P.S. I had to separate the WUR into three parts actually to get to the diaphragm and see what was happening at the thread level of the warm control adjustment.

I can think of two possible reasons for the high control pressure when warm. One, is the wrong vacuum line attached to the diaphram at the bottom of the WUR? It should only have vacuum during deceleration which increases control pressure and leans the mixture. If it has constant vacuum it will incorrectly keep high control pressure all the time. Two, if there is a blockage in the housing for the FD relief valve, it is possible that residual fuel can not bleed off the WUR thus causing high control pressure.

928 Intl has Rebuilt ones for $195, I may have a good used one for 1/2 that. I ended up buying a new one from 928 Motorsports thinking that was my issue (which it wasn't). If you are interested, I would need to install it back on my Euro to make sure it's functioning as it should. I would shoot a video of it of course to prove it's worthiness. If you don't want it, I'll throw it up for grabs for $100 plus shipping fees (after I test it of course).

You may have a badly tuned WUR, but I don't think this is your main problem.
The business with the "push air metering plate down by hand = less fuel at injectors" that you described earlier points to a serious problem somewhere else, probably the distributor or fuel delivery. I cannot think of a way that the WUR could directly cause this behavior. Have you checked the fuel delivery rate? Has the fuel filter been changed recently. Is the bottom of the fuel tank clean? Debris in the tank could slowly plug the filter at the tank outlet during operation, slowly starving the fuel pump. Shutting the engine off would then let this junk fall off the filter screen until the next operation. This could be worse when the tank is near empty, with fuel sloshing around and stirring up junk.

The return from the WUR goes back through the pressure regulator valve apparatus in the distributor and this could also be a problem, as DPW has pointed out.

If you want to get the WUR set up, you have to do it in stages. You have to get the warm pressure right first, because the heated rod is supposed to deflect up as it heats up and put less and less downward pressure on the spring plate until it puts no pressure at all. So basically, if you take the control rod out completely, you can tweak the warm pressure. Setting the cold pressure first with an incorrect warm pressure does you no good.

DPW is right about the vacuum lines. But this should only make pressure about a 0.6 bar higher if the springs are set up correctly and it sounds like you are even farther off. The test values in the workshop manual are specific about whether they should be measured with or without vacuum. Vacuum is applied at the side port, not the top port.

Be careful with the screw at the bottom of the WUR so as not to tear the vacuum diaphragm. It sounds like your warm pressure is too high. Are you sure the filter at the inlet is clear? If so, you can try this test: Put a few thin shims in between the edges of the two WUR body parts at the regulator end while screwing the two halves back together. Does this lower your warm control pressure? It should. If this works and turning the screw is not having any effect, you can take out the shims and try making a new control rod to go between the regulator and the spring plate. Use a nail about the same diamter and make one that is just a tiny bit shorter than the original rod (I'd keep the original unmodified for reference). Round the ends. Then file off a tiny bit at a time if it's still too high until you get where you want to be. If it gets too low, you will have to start over.

If you want more help, consider posting the following pressure values:

1. control pressure with heated rod and all springs removed.

2. control pressure with only heated rod removed, springs in place, vacuum lines detached

3. same as #2 with vaccum at side port of WUR

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Great info guys. Now I have something to do tomorrow morning before work.

I would be interested absolutely MPDano if this is my problem. Let me take a day or two to check out all the new theories that just came in and I'll post it here If I still need one.

The vacuum is interesting. I did notice continual vacuum from the base WUR hose and I just assumed that was what should be happening.

I will also get the readings that you are asking about Luis. As for blockage, all is clear. I'm constantly checking the screen at the WUR and the filters inside the distributor injector bolts and have not yet found one blocked.

Here are a couple of pictures of my lawn art by the way. I hope to one day get it on my lawn.http://forums.pelicanparts.com/uploa...1335474891.jpg

MPDano, was that WUR out of a manual or automatic. I've noticed some parts houses make a distinction between the two. I can't imagine why, but then again...I am far from a Porsche/Bosche engineer.

http://forums.pelicanparts.com/uploa...1335475296.jpg

I don't think it matters but it was off an Automatic CIS Car. I will pull up the numbers on top since that will tell you something. I can't remember what, but it does.

I found pics of my WUR installed in my car.

http://forums.pelicanparts.com/uploa...1335482002.jpg

http://forums.pelicanparts.com/uploa...1335482011.jpg

http://forums.pelicanparts.com/uploa...1335482012.jpg