Help with Cold start on CIS system

[brentrussell]

Hi All, / Tony

Yes I have searched extensivley and researched a heap on this already , this has enabled me to get to the point I am now and looking for where to head from here please.
My car is a 73 with a 81 ROW SC CIS engine that I have been building for a long time! got the engine running approx 2 months ago, set the timing run it 3-4 times and it was excellent. One week later I tried starting it and it wouldnt start.
It fires but dies straight away, feels like no fuel almost as if firing on some cyclinders but not all.
I hotwired the fuel pump and tried pushing the flap up a few times which does give the squirting pulse sensation in the airbox.

Not sure where I printed it from but I have performed a Fuel pressure test this afternoon to clarify the below that was on the list of to do's.

1. Year of engine: 1981
2. US or RoW (Rest of World): ROW
3. WUR model number: BOSCH 086 OR 980 352 112 no idea which way around these numbers should be
4. Ambient temperature at time of test (in degrees C): 11deg celcius
5. WUR Resistance (in Ohms): My multi meter was dead... and we NEED to know this.
6. System Pressure (in bars): 4.7 bar
7. Cold Control Pressure (in bars): 1.65 bar
8. Warm Control Pressure (in bars): 1.65 bar ####
9. Time delta for Cold -> Warm Control Pressure (in minutes & seconds):
10. Residual Pressure @ 5 min (in bars): 1.6 bar
11. Residual Pressure @ 15 min (in bars): 1.5 bar
12. Residual Pressure @ 30 min (in bars): 1.4 bar
13. Residual Pressure @ 60 min (in bars): 0.55 bar

Re #8, I ran this for 10 minutes and it still didn't raise above the Cold Control Pressure which it went to instantly.

When I turned off the fuel pump after #13 the gauge went to 2.0 bar.. not sure if this is relevant.

I need to check the 0hms reading of my WUR which I will do tomorrow on a borrowed multi meter, it seems there is a issue here hence why my Warm Control Pressure didn't rise, so will investigate this.
Would this cause a non start though?

While fiddling with it yesterday I removed #1 injector and this was dribbling fuel while the fuel pump was turned off.. pretty sure this shouldn't be happening.

Another thing I think I need to check is the fuel delivery to each injector? I have 6 bottle which I can use to place each injector in and run for 30 sec's? or 1 minute?

I know a bit to digest and it will make sense to some of you, hopefully I'm heading in the right direction? please let me know if not and where to from here.

Many thanks Brent

[brentrussell]

Thinking my WUR numbers are wrong... will remove it for better identification.

[boyt911sc]

Originally Posted by brentrussell

Thinking my WUR numbers are wrong... will remove it for better identification.

Brent,

Bosch WUR (0 438 140 xxx). The last 3 digits identifies a particular unit. Use a 12-volt test light to confirm you have power at the plug when the FP is energized (running). Anomalies I noticed from your information:
a). WUR identification.
b). Power supply to WUR.
c). Fuel leak from injector/s.

The system pressure of 4.7 bar indicates that the FP is good and working. Test the FD by running the FP (with a fully charged battery) only with the fuel injectors installed and removed for leak tests. Include the CSV in the test too. Keep us posted.

Tony

[gomezoneill]

It's a 73 I think the WUR only gets power when the engine is running with a charging alternator.

[boyt911sc]

Originally Posted by gomezoneill

It's a 73 I think the WUR only gets power when the engine is running with a charging alternator.

Michael,

The guy has a '73 car with an '81 ROW engine.

Tony

[gomezoneill]

Originally Posted by boyt911sc

Michael,

The guy has a '73 car with an '81 ROW engine.

Tony

I know. Did he retain his original WUR wiring from the old 73 harness? That's of course a guess.

[brentrussell]

Thanks for considering this.
Used the 81 Engine/ Chassis loom and then the 73 Dash/ front loom so I think it's as per 81.

Brent

Originally Posted by gomezoneill

I know. Did he retain his original WUR wiring from the old 73 harness? That's of course a guess.

[boyt911sc]

Brent,

Your WUR should be 0-438-140-089. Confirm that you have the correct WUR and we'll start diagnosing your CIS problem/s. You would need a CIS pressure gauge to help us diagnose the culprit. Keep us posted.

Tony

[brentrussell]

Hey Tony,

At car now and can confirm WUR # is
0438 140 112 not 089!
Also re wur resistance shows 64 or 45? Depending which way around you put terminals... is that right?
I'm pretty average electrically so you will have to bear with me

Just about to check injector lines for leakage.

Regards

Brent

[brentrussell]

Also should this be connected?

[boyt911sc]

Originally Posted by brentrussell

Also should this be connected?

Brent,

That is the TTV (thermotime valve) for the WUR. Look for an electrical plug laying around the 1-2-3 intake runners area. I will look for a picture and post it later.

Tony

[boyt911sc]

Brent,

Found the picture of the TTV and the plug.



Tony

[brentrussell]

Hey Tony,

Yes found that plug... is it specific which way round it goes? As it seems to be able to go either way.
Also the wire Colour are different on mine to your picture... mine are red with white and brown.
Received your pm also, will reply further when I get home thanks.
I have also performed some tests and will put that data on this thread also.

Brent

Originally Posted by boyt911sc

Brent,

Found the picture of the TTV and the plug.



Tony

[boyt911sc]

Originally Posted by brentrussell

Hey Tony,

At car now and can confirm WUR # is
0438 140 112 not 089!
Also re wur resistance shows 64 or 45? Depending which way around you put terminals... is that right?
I'm pretty average electrically so you will have to bear with me

Just about to check injector lines for leakage.

Regards

Brent

Brent,

This could be your lucky day. I have a collection of assorted WUR's for 911 including a dozen WUR-089 but has only one WUR-112 in my inventory. I have a proposal to you and you have to decide quickly.

I will ship to you a calibrated, tested, and rebuilt WUR-089 if you agree to swap or exchange your -112. My wife is leaving for Sydney in a few days and I decided to stay home this time to finish another engine rebuild. My wife will bring the WUR-089 to Sydney and ship it from there to NZ and you will ship the WUR-112 to Sydney. If this proposal is acceptable to you, we could finalize the detail via PM or emails. And we have a few days to finalize the deal before she flies down under.



I was in NZ last year and saw the vast earthquake devastation in Christchurch. And the city has amazingly bounced back in a short time. You have a beautiful country.

Tony

[timmy2]

Tony, he mentioned it is a Euro motor, so it has the TTV and possibly a different WUR than t089. Perhaps the 112 has the vacuum functionality like the 045?

Brent, Tony's wires are Red/White and brown in his photo.

[boyt911sc]

Originally Posted by brentrussell

Hey Tony,

Yes found that plug... is it specific which way round it goes? As it seems to be able to go either way.
Also the wire Colour are different on mine to your picture... mine are red with white and brown.
Received your pm also, will reply further when I get home thanks.
I have also performed some tests and will put that data on this thread also.

Brent

Brent,

The color of the wires shown in the picture are same as yours. Same color from factory wiring diagram. We both have the same wires color. I find no differences (?). One of us could be colored blind (joke). You will be fine.

Tony

[boyt911sc]

Originally Posted by timmy2

Tony, he mentioned it is a Euro motor, so it has the with TTV and possibly a different WUR.

Brent, Tony's wires are Red/White and brown in his photo.

Dennis,

If there was something wrong with the wire color, I would deny anything to do about it and put the blame to someone else. Fortunately, you did a good job. You are safe. BTW, US '81~'83 use WUR-090 while the ROW/Euro '81~'83 use WUR-089. WUR-112 is not the correct WUR for Brent's engine and will not work. It is for a completely different application.

Tony

[brentrussell]

Dennis/ Tony,

Thank you for your assistance!
I will reply in more detail later tonight as just walked in the door.

It runs!, checked, connected, adjusted and changed a variety of different things and it started first time, idles mint.. seemed like a heap of un-burnt fuel coming out exhausts... more about that later.

Re the WUR issue, not sure whats up as it runs with this WUR and has done a month or two ago plus previous owner fine... perhaps I have got a different engine to what I thouht I had? Checked the engine Type on casing below fan and its a 930/10, does that help?

Brent

Originally Posted by boyt911sc

Dennis,

If there was something wrong with the wire color, I would deny anything to do about it and put the blame to someone else. Fortunately, you did a good job. You are safe. BTW, US '81~'83 use WUR-090 while the ROW/Euro '81~'83 use WUR-089. WUR-112 is not the correct WUR for Brent's engine and will not work. It is for a completely different application.

Tony

[boyt911sc]

Originally Posted by brentrussell

Dennis/ Tony,

Thank you for your assistance!
I will reply in more detail later tonight as just walked in the door.

It runs!, checked, connected, adjusted and changed a variety of different things and it started first time, idles mint.. seemed like a heap of un-burnt fuel coming out exhausts... more about that later.

Re the WUR issue, not sure whats up as it runs with this WUR and has done a month or two ago plus previous owner fine... perhaps I have got a different engine to what I thouht I had? Checked the engine Type on casing below fan and its a 930/10, does that help?

Brent

Brent,

Engine type 930/10 is the stock engine type for '81 SC ROW and they use WUR-089. If you are happy and satisfied to use a completely different WUR, it is a decision you have to make. The heater resistance (Ohms) of your WUR will produce a completely different fuel pressure profile than the recommended WUR-089. Vereeken (Michel) recently posted some information for '81 SC RoW control pressure chart. Take a good look. Even the test procedures for these WUR's are different. Keep us posted.



Tony.

[GaryR]

Do the deal with Tony and be done with it! He is THE man with this stuff...