Cis control pressure .5bar

[roadster49]

Hello everyone - my 83 SC ran fine. Then had/have charging issues so found the battery was bad. New battery and alternator installed but when I tried to fire her up no start.

Put the fuel system gauges on to test pressures.

- system pressure is 4.8 B but control pressure is only .5 B,with WUR plugged in after 8 minutes and ambient temperature 40 F. Showed no sign of rising. 25.6 OHMS resistance on WUR.

- I am wondering if WUR leads are getting power and if not what to check.
- Since it has not started cannot confirm charging issues are resolved.
- FP is original
- New fuel filter
- New gas tank
- rebuilt WUR & FD last year


Thoughts and recommendations greatly appreciated.

Roadster

[boyt911sc]

Michael,

You don’t need a running motor to do the fuel pressure tests. Do you know how to test run the FP using the FP relay socket and ignition switch @ RUN position? You will need a suitable wire jumper and preferably with an inline fuse and toggle switch (optional).

Or send it to me and I will test your WUR. Even if the electrical plug to the WUR is disconnected, your cold control fuel pressure should be at least 3 times greater than what you were having. Need to test and evaluate the WUR if it is the culprit. PM sent.

Tony

[Vereeken]

Well I am going to get flack for this but 0.5 bar is possible as ccp on a Euro 83 sc with a 089 wur at 4 degrees Celsius and no vac applied.
I got a hold of the 089 testing report by one of the German based Bosch remanufacturers an they would set the 089 at 0,6 bar at 10 degrees Celsius with no vac applied. With vac applied they want to see 1.2/1.4 bar
I did that as well and at first was unable to start the car but after going back to factory setting on dizzy, co and air bypass the car started and did the high idle thing.
Your aav and aar also need to work perfectly for the car to start at such a low bar setting.
Having said that many Germans complain afterwards of hard start with their sc after the rebuild, but technically it seems to be the correct setting for that temp.
Of course 0,5 bar after 8 minutes of power to the wur is not good, that is a busted bi metal.

[boyt911sc]

Michael,

The package containing your WUR-090 arrived yesterday afternoon. Opened the box this morning and had a chance to do the initial test. The cold control fuel pressure was less than 10 psi. So I proceeded to do further inspection and to my surprise, the interior was so corroded. See picture below.



How did you get this corrosion/dirt in the first place? I’ve never seen anything worse than this before. Secondly, the reason for the very low control pressure was due to the dislodged pin. I found the pin floating inside the WUR. Were you tinkering this WUR? My record shows that I sent this WUR in July 2015 and you recently drove the car. Anyway, I have to clean and fix the problem and send this back to you.

Tony

[roadster49]

Tony,
Never opened the WUR. Installed it and drove the car. Not sure why it is so corroded. Don’t know how the pin came out. Never tinkered. Appreciate your help.

Michael

[Vereeken]

Never seen anything like that not even on a wur sitting in a car graveyard.

[pmax]

Originally Posted by boyt911sc

...
How did you get this corrosion/dirt in the first place? I’ve never seen anything worse than this before. Secondly, the reason for the very low control pressure was due to the dislodged pin. I found the pin floating inside the WUR.
...

No CIS expert here but given this is the technical discussion forum, I will hazard a guess.

What's the failure pressure of the round control plate/O-ring when the pin is no longer supporting it ?

The crud could be gas which has gotten into the WUR body and congealed.

Originally Posted by boyt911sc

...
Were you tinkering this WUR?
...

Not sure about roadster49 but to me and many others I would think, the real fun with these obsolete gadgetry is the tinkering.

Just saying.

[roadster49]

PMAX,
Totally agree with your “tinker comment”. You can’t find shops to work on these cars anymore or they want upwards of $125/hr.

I have had this car since 2010. It was not in till 7/15 when Tony rebuilt the WUR and the FD that it was fun to drive. In 5 years preceding rebuilt the engine, Replaced the upholstery, clutch assembly and a ton of other parts. It has been a frustrating journey but when it is running and people yell “I want to buy your car, name your price’ I feel a tinkerer’s sense of pride.

[pmax]

^^^ Nicely done. You are obviously an excellent "tinkerer".

Question ... do you have a recent pic of the WUR installed in the engine ? I'm curious if any of the crud has spilled out around the unit.

[roadster49]

Sorry PMAX, don’t have a recent pic. However, there is a rubber seal around the WUR that remained intact and avoiding any spillage. See post # 3 from Tony.

OH Excellent Tinkerer AKA “ET”

Lol
Roadster49

[steely]

That IS a good looking car.
And +1 to tinkering.

[HaroldMHedge]

Tony,

For the cause of corrosion be a failed O-ring seal?

Harold

[boyt911sc]

Originally Posted by HaroldMHedge

Tony,

For the cause of corrosion be a failed O-ring seal?

Harold

Harold,

I have not opened the “block” that has the metallic diaphragm. The WUR investigation is delayed a few days due to other work loads and other CIS commitments. I am also intrigued about this abnormality. Will keep you posted.

Tony

[boyt911sc]

Michael,

I apologize for the delay. I have a detached work area and the weather here in Philadelphia is really giving me a hard time doing some quality work. The rain and snow kept coming weeks after weeks. And there is another snow storm coming tomorrow. The work is half done and will update you ASAP.

The engine rebuilding classes that I will be conducting this month is taking so much of my time. The two motors that will be used in the class for demonstration and hand on experience were finally ready after weeks of prep work. Will PM you for the exact delivery date. Please accept my apology.

Tony