Got it all set up. Ambient temperature is 22 degrees C outside.
Ignition on, FP running, engine stopped, CDI unplugged. Flushed the gauge. WUR electrically connected.
0:00 - 1.0 Bar at startup
0:50 - 1.5 Bar
1:35 - 2.0 Bar
2:50 - 2.5 Bar
4:10 - 2.7 Bar
5:00 - 2.7 Bar
6:00 - 2.7 Bar
7:00 - 2.7 Bar
At 7 minutes I got bored. The WUR was a little warm, but not significantly. I started the hair dryer, directed at the WUR from the driver's side at close range.
After 3 minutes of hair dryer, the pressure was still 2.7 Bar. The WUR was significantly warmer to the touch, its not the best hair dryer but it is pretty good.

I spent 12 minutes getting the baby bottles set up and the injectors in them. Then I got ready to run the injectors. After I turned on the FP for the baby fill, I looked at the gauge and it had quickly returned to 2.7 Bar. It stayed at 2.7 as I sprayed baby bottle gas by pushing the sensor plate. The pressure remained the same at all levels of spraying velocity, although it did wiggle a little when I changed sensor plate position quickly.

Volume is very close to equal across all injectors.

http://forums.pelicanparts.com/uploa...1436483967.jpg

WUR is magic number 089!

http://forums.pelicanparts.com/uploa...1436483983.jpg

I'll do a starting video later after it has cooled down (and I get back from anniversary dinner).

On second thought, video may be tomorrow!

I think that is not the correct WUR. This came up in another thread today. Tony stated that -089 is from a Euro car. It does not match the numbers in the Bentley. Look at your door jamb on the driver's side and see if there a placard. That should tell you what month your car was manufactured. Now what I don't know is if -089 is an "acceptable" substitute for the others listed. Maybe you're ok there. But your WCP readings are dependent on the WUR.

Good job on the injector test. That looks like a great result. So no cylinder is being flooded.

I still highly recommend moving the air plate by hand up and/or down while at idle. If you can correct the idle by pushing the plate upwards then you are to lean if you find you need to push the plate downward to make idle better your to rich. This simple test will help you understand if you are lean or rich during the poor idle condition. If moving the plate in either direction does not help much then the issue may not be fuel related.

The injector spray test you did into the bottles helps confirm the injectors are all spraying about equal, they look good.

One last thought: you don't suspect a cracked air box from a intake back fire? With the ignition issue you had did you ever have a bad intake backfire? If so you could have a cracked air box and a false air leak.

Sal,

I like your thinking.

The OP did remove the CIS components a while back. Found and fixed the vac leak on the merge pipe that connects to the decel valve, AAR and AAV. I believe at that time he checked the airbox for cracks and did not find any.

Still it might be worth using the carb cleaner or unlit propane method to verify there are no leaks? That's assuming he can get the engine running long enough...

Some spec book screen shots:

First is for a Euro 82/83 model with the 089 WUR that you seem to have.

http://forums.pelicanparts.com/uploa...1436494952.jpg

Next is for the 78/79 SC.

http://forums.pelicanparts.com/uploa...1436495053.jpg

Does your WUR even have the vacuum port? According to these spec books both have a vacuum port that affects control pressure based on intake manifold vacuum. I don't remember having seen this mentioned. Anyhow, without intake vacuum (e.g. engine not running) your value is at the lower end of the spec. with 2.7 bar.

Never mind, I see you do have the vacuum port. Do you have the ability to pull a vacuum on this port and see if the warm CP goes beyond 2.7 bar? Or, did you observe the warm control pressure going higher than 2.7 bar when the throttle closes and intake vacuum builds when you ran the engine?

I pasted this comment from Tony from another thread.

Can you post a wider view pic of your WUR? The -089 WUR is supposed to be vacuum-assisted. I'm thinking Ingo is right -- that either you need the vac assist to get to higher control pressure or someone has modified your -089 to function without it.

Looking at Ingo's post above, the control pressures look similar between the two WUR models but they both seem to rely on vacuum to get higher control pressure. Your 2.7 value is at the bottom end of the normal range for WCP.

So the question is SHOULD you have a vac line? What is/was connected before?

Tony's comment that the other internals are different is interesting to note too. Probably explains your high resistance value.

Is it possible that your WUR is warming up too quickly? Perhaps it is leaning the mixture out faster than it should.

Does the car start ok now? If it does, about how long does it take time-wise before it starts having rough running?

Thinking again... If 2.7 is too low, then you are staying too rich when warm (assuming everything else is fine). Higher pressure means leaner mixture, lower means richer. Sal's test with the pressure plate to lean the mixture should help the running condition. If it doesn't there is something amiss.

If you got a hand vac to test the AAV maybe you could try faking it by pulling a small amount of vacuum on the WUR port to see if WCP rises any further.

Lots of good questions. Here is what I know.

It could be lean condition. I'm not yet an expert "sniffer", but I don't see dark smoke when starting, and I don't smell a strong smell. I can do the air plate raise test.

At initial startup, it runs without additional throttle. Within a minute or two, it requires throttle applied in order to run. A few days ago I ran it for 10 minutes by holding the throttle at around 3K. If I let the throttle dip and try to push it back up again, it sometimes won't return.

Once it has gotten warm, 1K RPM is no longer maintainable - only higher RPMs allow it to run smoothly. This leads me to believe idle adjustment isn't the immediate problem.
I tried putting carb cleaner into the intake, but restarting when warm is very difficult regardless of carb cleaner or not.

I can monitor control pressure during the warm up cycle. I'm not sure how to do system pressure while the car is running - doesn't that require the gauge to be set to block fuel from the fuel distributor to the WUR?

Timing is set to to what was 5 degrees advanced before the CIS teardown/cleanup two weeks ago. Maybe I can time it in brief time it idles after cold start? I can at least check the timing then.

I've had a couple louder backfires, but none since re-assembly. The airbox was cleaned and examined carefully while it was out, and had no apparent damage. It has a pop-off valve (although I know those aren't 100% fool proof).

I can try that again. I did attempt it during the original hunt for problems a few weeks ago, but did not find anything. I have entirely new rubber hoses for those between CIS components, other than the two special ones to the AAR/AAV. The other hoses seemed in good shape, although I can't be 100% sure.

I have a hand vacuum pump I can put on the WUR. Would I run this test with the FP on but engine off? During my control pressure test yesterday, the control pressure did not go up when the throttle was opened and closed (although the dial did flutter a little bit). Perhaps the thermovalve did not open properly, and thus was not passing pressure from the throttle body to the WUR.

My WUR is vacuum assisted. No obvious modifications were visible during my disassembly a few days ago. The vacuum line has always been connected to it. I don't know if the warming speed is correct - is there a good way to tell?

Here's what I can do tonight to provide some more data. I'll set up my phone as a video camera where it can see the control pressure fuel gauge dial as well as hear the engine. Then I'll do a cold start. When it begins to warm and the idle drops to "I'm dying!" level, I'll open the throttle and run it for a few more minutes. Then I'll let it die. This should give us a good record of the times and behaviors. I can also throw in the plate-lift test during that run.

I suggest you have the 3mm allen key in the slot for setting mixture, this will allow you to lift the plate from below with you hand or push the plate down from above by pushing on the allen key. We simply want to know what helps it idle better, lifting or lowering the plate. This test alone will at least give us an idea if it's lean or rich.

Good plan.

Try this as a quick test before starting the engine.

Run the fuel pump only with the WUR plugged in. Have your hand pump connected to the vac port when you do this. As control pressures rises to 2.7 max start pumping the hand pump and see if you can get the CP to increase beyond 2.7. If it does then you know that the vac assist is functioning as desired.

You can temporarily disconnect the WUR electrical connection and then use a can of freeze spray or an ice pack to drop it's temp back down to simulate a cold start.

Then set up everything for a normal cold start test again. WUR electrical connected. Have your hand pump ready and start the car. What we want to see is how long it takes to transition from cold to warm running and what the engine is doing at the same time. If you can run a timer in view of the camera then it will be easier to see what the fuel pressure is at what time and then correlate that to engine behavior.

I'm thinking that once you get to 2.7 bar is about when you'll transition to rough running. If you then can pump your vac, and the control pressure increases and the engine runs smoother then we know you're close.

Next step would be to disconnect the hand pump and connect it to the normal vac line. If the control pressure goes back down then maybe the other end of your vac line is plugged into the wrong place or some other issue?

Once we know that the normal vac line is working properly then it is a matter of getting the right base adjustment.

Yes, and be ready to do as Sal suggests. That should be very quick and easy.

Just my thoughts on diagnosing this issue: Personally I would not concentrate to much on cold start YET. I'd get the WUR warm and engine warm if possible then check the control pressure and if it's in the 2.7 to 3.0 bar range that engine should idle fine if it does not something else is wrong. At this point we need to know if your rich or lean so we can decide what to do next.

I'm not dismissing the cold start issue, I'm simply suggesting not getting to focused on the cold start problem since it's not the major bad running condition. What bothers me is why this engine won't idle warm, and if the control pressure is in the ballpark of 2.7 to 3.0 bar it should idle just fine. I'm suspecting something else is also wrong besides just the WUR.

Sal,

I believe what the OP is seeing is that the COLD start works fine. But as the engine transitions into warm things go south especially during idle. What we know is that warm control pressure is in the ball park of 2.7 without intake vacuum (test with FP running but engine off and element warmed up)

I believe the OP is on the right track and we need to understand what the mixture does at idle as the engine transitions into warm condition. From what I understand the vacuum-assisted WUR should always see the high intake vacuum at idle (throttle closed) and the CP should be always about one bar higher if the vacuum-assist works (e.g. ~ 2 bar when cold @idle, ~3.5bar when warm @idle)

I am curious about the test with the hand pump (FP running, element heating, engine off -> 2.7 bar, then hand-pump and see if the CP raises by about another bar)

Ingo

Ingo,

I agree with you, my point is don't worry about the cold start much just yet.
Also do we know if the WUR vacuum line actually is connected correctly at the other end? Do we we actually have vacuum at the WUR? I'd verify this as well.

Yes - then we had the same thoughts: Once we know vacuum from the hand pump impacts the WUR let's confirm the WUR "sees" intake manifold vacuum properly. As you said it could be a blocked port or connected to the wrong position.

I wasn't trying to focus on cold start. I really just wanted to hear how the car starts cold when he makes the video. I think the CCP is probably fine now. Since the OP is having trouble keeping the car running when warm I didn't want my suggestion of the previous test to interfere with his ability to start and run the car long enough to do some more diagnosis.

Maybe OsoMoore should just skip the test of running just the fuel pump and go straight to running the engine?

If a picture is worth a 1000 words, a video has to be worth way more than that, right? :)

OsoMoore,

BTW I can mail you a wideband O2 gauge, but your car doesn't have an O2 sensor bung right? I suppose there is some chance you have an aftermarket exhaust that has a bung for the O2 sensor welded in already. You'd want it to be installed before the cat.

Do you have a cat?

Tim, indeed I do not have an O2 sensor. I believe I have a cat bypass with a plug of some kind in the hole that would be the O2 sensor. But to be sure, I'd have to take a look underneath.

It probably isn't worth sending it to me, however, because I'm going to leave it with the experts Sunday night/Monday morning before I head off on vacation. Assuming I don't get it running before than. I can't afford the time to dedicate to daily car work any further - we have a baby adoption on the way and attention is required elsewhere!

My friend with the CDI and lots of patience is coming over tomorrow morning. With your help and his, I will hopefully be running before I have to do the drop-off.

Not sure if this was already done, but have you tried starting the car without the gas cap in place? A clogged vent in your fuel cap would cause less fuel to flow.

I know it is stupid, but why not cover all bases?