CIS WUR Parts Number Question now help getting initial mixture settings
 

I have a 78 3.0 motor with CIS. Last weekend it wouldn't make any power or review. But the pressure gauge on the Fuel system and fuel pump test good with 70 psi valve closed. However with valve open I'm seeing less then 1.5 bar. Looks like I need a new WUR as all the WUR charts in the Bentley manual say I should have 2.5 bar plus for a 90 degree outside temp. I pull the WUR and look at the parts number and it is 0 438 140 089. This is not listed in Bentley as a possible WUR for an SC ( not sure why). Specialty Auto shows this as a 911 WUR from the 80's. Car ran and drove fine with this WUR for 5 years. Do I send in the WUR I have and have it rebuilt and throw it back on the car or should I go for a 0-438-140-045 or some other WUR? Am I worrying too much as it worked fine before?

Nick

Whatever you chose to do, do not send it to Specialty for repair, it's unlikely you'll get it back in working order, and just wait until you try and deal with the guy over that. Look up Brian Leask or Rarely8 on this board and get the 082 rebuilt and/or modified to be fully adjustable and it will work fine.

His Pelican handle is actually RarlyL8 - can't go wrong with either him or Leask (I've patronized both) . . .

The -089 WUR is correct for a 1978/9 Euro 911SC.
I have these in stock, can rebuild yours or do an exchange where you send your core after you are up and running. Shoot me an email if I can help.

The 089 suffix identifies your WUR as a WUR built for EURO SC's.

Off the top of my head I believe first used in the SC's EURO from January 81. So not original to your car.
This does not mean an issue or problem juste that it has been replaced before.

Here is a link to a post of mine with the relavant chart for your WUR.

Your WUR should have two vacuum connections. One on top to atmosphere.
One at the side for Vacuum.

Notice the testing procedure values of this WUR and the sentence that says Testin Vacuum 550mbar

http://forums.pelicanparts.com/porsche-911-technical-forum/678022-euro-sc-troubleshooting-over.html

How much does applying vacuum affect the reading?

it increases it with about 0,6 bar.

As I said I do not think it to be original to your car as teh Bosch production run of the 089 seems to start in January 81 but it is a correct WUR type for a Euro SC.
But I can be wrong as I do not have specific Porsche data only Bosh data.

Now car won't start
 

Got the new WUR installed yesterday and now the fuel pressures are within stock specs, so that seems good. But now the car will not start. I have two theories anythoughts on which I should pursue first?

1. I took the car to a shop because the idle was bad a while back. The adjusted the mixture with an analyzer and all was well. Could they have adjusted the mixture to compensate for a WUR going bad so the good WUR has moved the idle mixture so far off that the car won't run?

2. I installed a high torch started from Pelican. It only had one spade connector so I did not connect the cold start injector system thinking that this would cause hard starting not cold starting. Do I need to hook this up to get the car to start or is it a red herring

You need the cold start injector working.

What is your outside temparture and the bar reading of the WUR at dead cold vacuum to WUR disconnected?

The experience I have is that the CSV is great for preventing backfire when starting really cold but once at temperatures of 20 degrees celcius and up does not do much to improve starting.

Michel

2.4 bar outside temp 93

The CIS components are on an electrical daisy chain, if not plugged in none will work. CSInjector is on a thermo time switch and does not function when temps are that high.
Mixture may have been adjusted lean as an attempt to compensate for the off-spec WUR fuel pressures. If so you may need to manually pull the air meter plate and shoot some fuel to get it to fire and run long enough to adjust. If you don't have one, an AFR meter will be a tremendous help.

93 that is 34 celcius so the CSV is out (or perhaps active for only a second).
Also the thermo valve to the WUR will be open at that temp (or at most stay closed for at most a couple of seconds). So immediate Vac to the 089
2.4 at 34 celcius is in the ball park for the 089 (at the low side but OK).

So my guess from reading the above. Your first WUR was kinda FUBAR with a CCP (and perhaps WCP) that was likely too low thus giving more fuel ; the shop leaned it out by the mixture screw.
Now you have a functional WUR and the fuel delivery is lean from the get go.

This is the time to get an innovate LM 1 or 2.

Or turn the mixture screw 1 full turn clockwise. If it starts the above guess was right.

But you would need to reset CO again with the appropriate tools.

Michel

Just an update those who offered their advice. 4 turns of the idle mixture screw got the car to cough to life. When it did start it spat about a 1/2 cupof gas out of the tail pipe. Let the car warm up with a fast idle and slowly adjusted th idle screw and micture screw until I had a nice stable idle. I will put it on an analyzer later this week but as of now the car drives and idles well. Thanks for the help!

Nick

Did the new WUR fail? Outside temp is 26 C control pressure reads 3.0 bar no vacuum applied as I don't have a means to apply vacuum. Car was put away running fine now it will not start. Just cranks and cranks. Confirmed spark and CD are ok. I never had a chance to get it on an analyzer so it only ran and drove once with the new WUR. Went to drive the car today for the first time and no go managed to get it to run for a couple minutes with my foot flat on the floor. It smoked badly and backfired both through the exhaust and the intake. would not rev. 1000 RPMs foot to the floor. As soon as I took my foot off it dies. Thoughts?

Huge vacuum leak? Pop off valve not seated?

Doesn't appear to be a vacuum leak. Pop off looks good and all hoses are relatively new

Is there a known setting for the idle mixture screw that the car will run. IE turn all the way in one direction then back off x number of turns?

Not that I've seen. The last few pages of Needspace's thread about his '76 have numerous links to setting it up.
I'm on 2g in Montana on my phone so you'll have to look for it.

Can be a number of things.

A 089 WUR should post 2.5 bar at 26 degrees celcius. Given that you have 3 bar on the WUR means that the WUR will not let it run rich. Which is not a big worry at these outside temps.

I am unsure what you mean by 4 turns of the IDLE mixture screw in one of you earlier posts.

Do you mean 4 turns of the Idle screw (left of the throttle plate) or 4 turns of the mixture screw (allen type) on top of the FD an a pain to get to?

if the latter; 4 turns is a lot and I can imagine togheter with a cold cp from the WUR you are flooding the engine.

Smoke? White smoke that hurts the eyes? If so way too rich.

What would I do now? Try to warm up the WUR so that the pressure gets to warm control pressure. You can do that by jumping the Fuel Relay and turning the ignition on. The 12v will be applied to the WUR and the Fuel pump will be running. Do this for 5 minutes. Chech that battery is strong.

Give the idle screw 2 turns counterclockwise.

Start the car. If it starts throttle it to get it warmed up an burn off all excess fuel.

The following day you can start baselining.

The procedure for setting initial mixture is as follows (I do not recommend it, it is only for when everything is lost).

Pull out 1 injector. Put in jar. Jump the fp relay. Turn mixture screw until the injector starts to spray, then turn back 1/2 turn.

Initial setting for the Idle screw. 4 turns out from completly closed.