911 SC 1983 warm running issue

[Hyllski]

[Hyllski]

[boyt911sc]

Originally Posted by Hyllski

Ok, now I got what you meant. Engine was not running when I checked WCP after driving. So no vacuum on both tests.

Steinar,

That is what I was getting from your previous posts. So there is a clear misunderstanding how WCP is expressed. So from this point on we should clearly define if WCP is with or without vacuum applied. Otherwise, there will be confusions in our discussions. We are moving forward in the right direction. And you are doing fine.

Tony

[Charles Freeborn]

I haven’t studied all the comments. But I’ll add that there is a check valve in one of the lines which has to be on the correct side of your test kit fitting.
That threw me off once....


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[Hyllski]

Measured 34,9 ohms on my WUR heater this morning. Engine cold. 8 degrees Celsius (46,5F)

Steinar

[Hyllski]

And I had 12,1 volts on the WUR heater connection earlier when I did the fuel pressure testing.

[boyt911sc]

Originally Posted by Hyllski

Measured 34,9 ohms on my WUR heater this morning. Engine cold. 8 degrees Celsius (46,5F)

Steinar

Steinar,

Do you have a handheld vacuum pump? Test run the FP and observe the transition from CCP to WCP. Wait until it reaches max. (37 psi.) and apply 15” Hg vac. Vacuum is applied to the side port for WUR-089. Record this value.

If you have no handheld vacuum pump, simply run the motor with the gauge installed. Wait for the CCP to stabilize and max. out. You should be getting much higher than 37 psi. with the motor running.

For this investigation, we are only interested to measure the WCP. Leave the WUR electric plug connected and run the FP if you have a vacuum pump. Or simply run the motor with the pressure gauge connected. Keep us posted.

Tony

[Hyllski]

I dont have a vacuum pump, but will make the test with the car running.
A little busy at work until wednesday but will post results as soon as I get test done.

Steinar

[boyt911sc]

Originally Posted by Hyllski

Measured 34,9 ohms on my WUR heater this morning. Engine cold. 8 degrees Celsius (46,5F)

Steinar

Steinar,

Hard to identify the WUR from your picture. On top of the WUR there are some markings like “Germany”, “France”, or blank. My guess it is “France”. And I could be mistaken. Please verify. Thanks.

Tony

[Hyllski]

France is correct

[fred cook]

You could try hooking up an air/fuel gauge (A/F) and get a direct reading of the air/fuel mixture. At a warm idle, 14.7:1 (stoichiometric) is ideal. If you can run the connecting leads into the cabin then you can see if the engine is running rich or lean and in what situations. Getting the fuel pressures correct is certainly necessary but using the A/F gauge might help with the diagnosis.

[Hyllski]

Tony:

Ran the test today. Simply just startet up the car from cold with the pressure gauge connected.

CCP - 37 psi
After 1 minute - 42 psi
After 2 minutes - 45 psi
After 10 minutes - 45 psi
After 15 minutes - still 45 psi
Removed vacuum hose on the side of the WUR - Pressure dropped to 37 psi

Steinar

[boyt911sc]

Originally Posted by Hyllski

Tony:

Ran the test today. Simply just startet up the car from cold with the pressure gauge connected.

CCP - 37 psi
After 1 minute - 42 psi
After 2 minutes - 45 psi
After 10 minutes - 45 psi
After 15 minutes - still 45 psi
Removed vacuum hose on the side of the WUR - Pressure dropped to 37 psi

Steinar

Steinar,

The CCP is too high and the WCP is too low. You need to recalibrate the WUR to get the control fuel pressures with in spec. Otherwise, you will always have this erratic engine performance. Wish you are closer so you could try and test one of my WUR’s and experience how a well calibrated WUR does to a motor.

Find someone who could calibrate it. Or do it yourself. Keep us posted.

Tony

[Hyllski]

It would be nice to do it myself. What is the best way to do this?

I guess I’ll have to knock the pin that holds the metallic spring further in again to lower CCP?

What about WCP? Knock the bigger brass cap into the WUR housing to raise WCP?

Steinar

[AndrewCologne]

Here is the logic where you see the red arrows where to knock/pull on the WUR to adjust WCP and CCP .

[Hyllski]

Originally Posted by AndrewCologne

Here is the logic where you see the red arrows where to knock/pull on the WUR to adjust WCP and CCP .

That’s nice! Thanks!

[Hyllski]

Adjusted the WUR this morning. CCP is now 22 psi and WCP is 43 psi. Drove the car for 2 hours and it´s working much better now. Still not perfect on low rpm´s in 2. gear but I can absolutely accept the improvement.

Thanks for every comment and all your help!

Steinar

[AndrewCologne]

WCP seems to low ... is your WUR a vacuum based one? Or Is your engine a 930/16 with lambda system?
What irritates me is that yours got the metal fuel lines but also the valve behind the throttle housing. Maybe a mixture of CIS components(78/79 and 80/83), not shure. Tony maybe could clearify here.

[Hyllski]

The 43 psi WCP is without vacuum. Fuel pump running, engine not running. Still to low?

Steinar

[boyt911sc]

Originally Posted by Hyllski

The 43 psi WCP is without vacuum. Fuel pump running, engine not running. Still to low?

Steinar

Steinar,

43 psi. without vacuum is a good value. You need a hand vacuum pump to make your work easier. The spec for WCP for WUR-089 without vacuum is 42 psi. +/- (3).

Since you don’t have a hand vacuum pump, simply run the engine and let the engine do the work. The spec for WCP with vacuum is 52 psi. +/-(3).

Stay safe. Keep us posted.

Tony