How difficult is it to remove the AAR with engine in? I'll try to test it.


Can someone confirm for me - with engine not running, if I have a fuel pump relay bypass going, and the ignition "on" then there should be power to the TTY, WUR, and AAR - correct? ** Pmax gave me the answer
Jason

I'm trying to get my head around the increased pressure values as well.

Jason

Too many cooks in the kitchen.........
 

Jason,

I have been following this thread with interest right from the beginning and curious to see how it turns out. Stick with SkiVT (Mike S.) and we spent a lot of time together diagnosing his CIS problem. He did a lot of good investigative work similar to yours. He has given you sage advises and keep working with him till you fix the problem. Mike S. has a very systematic approach in troubleshooting and feedback from him was very good. Do the same for him. Keep us posted.

Tony

His patience, and that of pmax, are keeping me going here.
Hope all is well with you Tony.

Jason

testing methodology question as I can't reconcile the last two videos you posted: you can only test CCP once every 6 - 8 hrs, regardless of if you tested with or without starting your engine. No Engine Start Method: you come out after the car sits for 8 hrs and the engine and WUR are both cold. You use your jumper and test pressures without starting the engine, seeing CCP first. Once you plug the WUR in and get to your max WCP, you have a warm WUR. If you then start the engine, you are at WCP and not CCP. Engine Start Method: you come out after the car sits for 8 hrs and with your pressure gauge hooked up, you start the engine. You can observe CCP in the first 10 seconds or so. The WUR begins warming, mostly by the bimetallic strip and a little with engine heat, and you end up at WCP. In this method, you now have a warm engine and warm WUR. Using either method, you need to let the WUR cool off to again see CCP.

The problem with testing pressure with an engine start is things like the TTV also come into play. No engine start method lets you use things like a vacuum pump to test CCP and WCP, with and without vacuum applied. However, it also means you need to test the TTV separately as the WUR can have correct CCP and WCP both with and without vacuum applied AND things still not work correctly. If your TTV either doesn't work to hold off vacuum OR the vacuum hoses are not hooked up correctly, you will still have a cold idle problem.

Ambient Temp: your CCP is different across different daily temperatures (see the WUR chart). So if it is 100 out, your CCP will be higher than if it is 65 out. WCP cares less as the bimetallic heater and engine warmth overcomes cold ambient air.

Your video and your pressure results: you have posted CCP without engine started twice with very close results at similar ambient. You then have the video showing an immediate CCP at 3.0. If the vacuum lines are correctly hooked up and the TTV is working and ambient was similar, this isn't possible. Did you let the WUR completely cool down before starting the engine? Another way to test the CCP is start the engine after sitting for 8 hrs, with a golf tee plugging the WUR to TTV vacuum line. This guarantees no vacuum to the WUR and again, you will see CCP for the first 10 to 15 seconds. The CCP should be the same 2.1 you saw without starting the engine.

Last part of my rambling: testing more than one thing at a time makes it hard to figure out what exactly fixes the problem. The AAR is important but I wouldn't go there until you have this WUR and TTV thing completely figured out. BTW the easiest way to see if the AAR is contributing to your problem is to connect the two hoses at the AAR together using a piece of pipe (so bypass the AAR). You are guaranteed to have air as the AAR can't obstruct airflow.

TTV test and evaluation........well explained.
 

Mike,

Only a person who has a good understanding of how the system works could deliver such a message. I am very impressed with your work. There is another individual in this forum that reminds me of you with good skill in delivering a clear and concise message...........is Ossiblue (Larry). Hope LJ is doing well.



Jayson,

Communicate with Mike. He has done this troubleshooting before and with a good understanding of what is going on in the system. And keep us posted.

Tony

Thanks!
Jason

Lots of great individuals in the past (and current) have contributed to the knowledge of this forum. I couldn't have rebuilt it without understanding the CIS system absent that knowledge.

I will add that based on my digging into OLD threads the posts of psalt, Jim Williams, Peter Zimmerman and John Walker were exceptionally informative whenever the CIS topics came up.

Pay attention to every word they write !

LIRS6,

You're in good hands now but your AAR test, assuming it's done correctly which appears to be the case, does show it's not closing as it should be.

Good luck ! Keep us posted.

Thanks,
Jason

When the AAR remains open, the idle wouldn't drop normally compared to a functioning AAR. It doesn't necessarily mean the idle has to be "high" in your engine because of other factors, just that it doesn't drop normally.

Also, the AAR should be closed by the end of your WUR warm up fuel pressure test (w/o engine running).

Post #31..........
 

Jason,

Please review post #31. If the information you posted (red letters) regarding WCP are correct, then the WUR is one of your problems and it will never go away. You could spend all the time you want tinkering your CIS. Maybe you could get lucky. But you could not rely on LUCK all time to fix your nagging CIS problem. What you need is a set good working CIS components (WUR, FD, AAR, TTV, etc.) that are tested and confirmed good. Right now you are hoping that all these components are all good and working fine. But you do not know that as fact.

Tony

Agreed Tony, and this is what I am trying to address. TTV tested and functioning as it should. Now will next try to address AAR. Still wondering if AAR can easily be removed...? If I determine that all other components are in order, I suspect it will then be time for me to send you my WUR!

Thanks,
Jason

Yes there are two allen head screws to remove and it comes off the engine. They are a little tough to get to. Also need to disconnect both hoses and the power connection.

Test and confirm........
 

Jason,

There are several CIS components you need to test and evaluate to get your engine to run flawlessly. Check the following:

FD
WUR
AAR
AAV
DV
TTV
CSV
Fuel injectors
Including air box/POV and intake runner boots.
Etc.

All the above CIS components could be bench tested conveniently by DIYers like you or me using home-made tools. Or send them to me for FREE testing. Just take care of the shipping cost. Or send them to someone who will do it for FREE and I won’t be offended.

Tony

Because I am curious, Tony: are the wcp pressure readings in black text in spec w/o vacuum? And the red text out of spec w/o vacuum? The higher readings at lower ambient are confusing but I thought the black text was in spec. Either way test and confirm as you already said.

Couldn't get to any testing tonite, will try tomorrow
Thanks,
Jason

WUR-045 WCP spec.........
 

Mike,

Take a look at the WCP chart for WUR-045:

WCP (no vac applied): 2.7 ~ 3.1 bar (See PSM)
WCP (with vac applied): 3.2 ~ 3.6 bar (See PSM)

Jason got 3.5 bar (no vac) and 3.8 bar (with vac). See the red letter in post #31. These values are out for the specified range for WCP’s. Secondly, you want a 0.5~0.6 bar difference between WCP’s (with and w/o vac). His WUR was giving only 0.30 bar delta. Jason’s WCP values are too high for WUR-045.

Your WUR-089 has a different chart profile than -045.

Tony

Thanks Tony. I was focused on the results in the post below and not on the posted response to your question (at bottom). I was comparing the results immediately below to the various 045 WUR spec pages (several different versions from other threads). The difference in these sets of numbers is mysterious but no question 3.5 and 3.8 are high.


***********************************************
Originally Posted by LIRS6 View Post

The car :

'79 SC (USA)

Original 3.0 with WUR ending 045

Red font are readings taken today. TTV hoses reversed to normal position (hose from Decel Valve in middle, WUR hose on side)

Temp : 74 deg F 66 deg F


Test results :

FP only - engine not running

System pressure: 4.9 bar. 4.8 Bar

Cold pressure : 2.1 bar. 2.3 Bar

WUR Power connected

30 secs : 2.2 bar / 31.9 psi. 2.55 Bar
60 secs : 2.45 bar / 35.5 psi. . 2.6 Bar
90 secs : 2.7 bar / 39.2 psi. 2.9 Bar
120 secs : 2.8 bar / 40.6 psi. 3.0 Bar
150 secs : 2.95 bar / 42.9 psi. 3.2 Bar
180 secs : 3.03 bar / 43.9 psi. 3.3 Bar
210 secs : 3.1 bar / 44.97 psi. 3.35
240 secs : 3.1 bar / 44.97 psi. 3.4 Bar
270 secs : 3.13 bar / 45.5 psi. 3.4 Bar

************************************************** **************

Originally Posted by boyt911sc View Post
Jason,

What are your control fuel pressures at:
a). Initial CCP with and without vacuum?3.0 Bar @ 73F with vacuum - haven't done it w/o vacuum
b). WCP with and without vacuum after 5 mins.? 3.8 Bar / 3.5 Bar
(Am I correct in believing that if I disconnect the vac hose to the WUR, that I am testing FP "without vacuum"?)

I am reminded of a previous question that I had - Am I correct in believing that if I disconnect the vac hose to the WUR, that I am testing FP "without vacuum"? If not, what is the correct procedure to test?

Thanks,
Jason

Testing without engine running: pressures are without vacuum UNLESS you hook up your Mightyvac to the WUR and ad vacuum. I use either the hose disconnect from the TTV and plugged to the Mightyvac or a separate hose from the Mightyvac to the WUR with the WUR to TTV hose disconnected. I would use the no-engine running test if it were me.

Testing with engine running: best way is to plug the line from WUR to TTV. It may also be w/o vacuum just by disconnecting that hose like you did in your video, but I am not 100% sure on that.

Honestly, I would Fedex the WUR to Tony for his free diagnostic. Obviously your call on the next step.

BTW: if you remove your AAR for testing, there are little washers with the allen bolts. Be careful those dont drop off during removal and land down in the spark plug holes......

yikes, thanks for the heads-up!

FYI
http://forums.pelicanparts.com/porsche-911-technical-forum/1007529-erratic-wcp.html#post10178023

These statements from the post about that WUR with a similar vacuum "diaphragm" as is in yours caught my attention.

Eliminating possible issues
 

I had a chance to spend a little time on the engine this morning.

CCP at start-up :

https://youtu.be/4Nor8z0svq8

As you will see from this video, initial CCP was about 2.6 PSI. (This is way out of range - ambient temp was 70 deg F. Max should be 1.95 PSI). What influences FP?

After about 14 seconds, it moves swiftly up to about 3.0 PSI. This supports that my TTV is operating properly (SkiVT - I have the WUR hose in it's proper location on the TTV).

I drove the car for a while - maybe about 10-15 mins or so, and noted the FP - 2.65 PSI

I then detached the hose going into the AAR, and took this Video:

https://youtu.be/_6DM0JcI47M

This supports that my AAR is closing as it should.

My initial issues remain as they were; low idle at start-up, dropping idle during warm-up; stalling/almost stalling when out of gear.

So I think that I have at least eliminated the TTV and AAR as issues.

Tony has graciously offered to test my WUR, which I will pursue.

Any thoughts/comments?

Thanks,
Jason

Troubleshooting........
 

Jason,

If your cold control fuel pressure was 2.6 bar and suddenly increased to 3.0 bar this could be the result of the TTV opening. However, why did the WCP dropped down later? The WCP should remain steady while the engine is running unless the vacuum supply is deteriorating (?).

There are too many variables with your problem to solve it. You need to reduce or minimize these unknown variables by testing. For example, how much vacuum does your decel valve could hold? Same with the TTV. Same with the WUR. Same with the AAV. Finding and identifying this “weak link” will help solve your nagging problem.

The culprit is right there. But we don’t recognize it yet. A systematic diagnostic test will eventually lead to its identity. At this point, I don’t believe you/we are close to finding the most likely culprit(?). Don’t give up yet.

Tony

Couple thoughts:
1) your wur has menopause. I have seen the symptoms first hand!!!
2) since you know the ccp is out, you will need to get your wur refreshed/calibrated regardless. The wcp and vacuum testing would all be part of that exercise. So doing that now and knowing you may still have troubleshooting to do when its back could be smart.
3) you could connect a hose from the wur directly to the throttle body vacuum hose and bypass the decel and TTV. Maybe start the engine first and swap the hose in after warmup. This would eliminate twonpossible culprits adding to your data.
4) connect your mightyvac to the wur. Apply vacuum and see what vacuum level holds 3.0. Try a little more and less vacuum and watch the pressure change. You can also do this using the no engine start procedure and do it at ccp and wcp. The spec chart suggests the vacuum levels.

This all takes time but it will be worth it when you solve the actual problem.

Intend to address "2)" shortly

Thanks,
Jason

Out of my car, and off they will go to Tony.

http://forums.pelicanparts.com/uploa...1537323686.jpg

Thanks Tony!

Jason

WUR and DV tests..........
 

Jason,

The package arrived last Friday with the WUR and DV but was not able to do the tests till Sunday evening because of family affair. There is good news and bad news. The decel valve is good and working. It opens up @17” Hg. I prefer to have a higher vac reading and adjustment could be made. This is the good news.

The bad news:
http://forums.pelicanparts.com/uploa...1537824823.jpg

http://forums.pelicanparts.com/uploa...1537824823.jpg

http://forums.pelicanparts.com/uploa...1537824823.jpg

Is this WUR you sent to me the same one that you were testing in your car? Why is the cold control fuel pressure @ 70°F is 50 psi. (3.45 bar)? This is equivalent to the WCP (warm control pressure). The vacuum diaphragm is not leaking but could only pull 4 psi. (0.30 bar). You need twice as much like 0.7~0.8 bar vacuum enrichment.

Have not done anything on this WUR except did the pressure tests. Please let me understand why the cold control fuel pressure is so much different from your data. Keep us posted.

Tony

Tony - this is the same WUR. If you consider the video that I posted in post #11, then the results are similar. Why I have other results at other times, I am not able to answer. What’s next?

Thanks
Jason

Engine temperature........
 

Jason,

I reviewed the video and saw the 50 psi. initial cold control fuel pressure and went up to 56 psi. Apparently, your WUR needs some work and you have to make a decision whether to have it fixed or corrected. What you need now is a good working WUR that you could test and use in your car. Forget about your WUR for the moment unless you like to spend countless hours looking for something we do not know.

PM me if you are interested to have a tested and calibrated WUR-045 sent to you that you could install and try on your car. This is a loaner and you are NOT buying it. Return it back to me later. I have provided hundred’s of these WUR’s ( Bosch 0-438-140-xxx) to people in this forum with remarkable success. Keep us posted.

Tony

Thanks Tony, let’s take your kind suggested course of action, and I’ll test your calibrated WUR-045 in my car and report back.

I just sent you an email as well - PLEASE remember to include my fitting for the fuel line.

Jason

Tony -

Yours well received. I see that you have improvised a way to adjust the pressure - don’t worry, I will not touch anything!

http://forums.pelicanparts.com/uploa...1538241770.jpg

We have house guests this weekend but I will try to get to installing it.

Anything in particular that you want me to do?

- install, turn the key and see what happens? With/without gauges?

Thanks again - will report

Jason

Test run........
 

Jason,

Take your time and you probably still have some sort of jet lag from your travel. Install the WUR-045 that I sent you and hook up the CIS pressure gauge. Double check your fittings to the fuel lines and get the engine running. Record you initial CCP and WCP. Keep us posted. Thanks.

Tony

I then started the engine. I thought a friend was recording, but apparently he failed miserably to press "start." From what I saw, it first showed about 1.8-1.9 Bar, then jumped up to about 2.6 Bar (TTY), then over a min or two increased pressure to about 3.3 Bar.

Turned engine off. Tried to re-start, would not catch. Turned up (CCW) idle screw a bit, tried again and it coughed but started.

Letting it sit now.

Note: edited in Blue font to add data from 9/9 - shows the huge difference my WUR vs. Tony's calibrated WUR tested 9/30 Red font

Any thoughts/comments?

Jason

If you started it at roughly the 60mi mark, you should expect the wur to be at wcp either immediately or within a very short period of time. The wur warmed up as you registered pressures. It looks like it did that and then increased above the 2.6 because of vacuum. That is all good.

I would start it again after 6 hrs so the wur is cold. This will allow the engine tp warm up as the wur does. Your fuel mixture will initially be richer, which the cold engine likes. See what happens and report back. On the wcp running, you should try manipulating the plate again.

Start test results
 

Tony, et al :

Here are videos of various start tests:

First, a cold start (Car sat 24 hrs). I continued video to show what happens with the RPM’s over 2 mins, then shut car down and did a re-start:

https://youtu.be/B_lpok5DIYI

Then I did another restart :

https://youtu.be/18t6v58Doec

A warm restart:

https://youtu.be/SK0RSnhsX5s

Engaging clutch as approaching a stop :

https://youtu.be/EYepRHbMUL0

A hot restart :

https://youtu.be/tJm_zCjGq-M

(SkiVT - I did not have a chance to try your suggestion as yet. )


I sense that the car is running more smoothly, and the exhaust is not as intense as it had been (read stinky).

Await your thoughts/comments

Thanks

Jason

I know Tony hates messing with mixture, at least initially, but my opinion: you can call it a day with success (with the properly calibrated wur). Your idle hangs a little high as it warns up, which is not a bad thing. Mine does that when I have it set on the rich side, but I have an afr gauge hooked up at all times. I have been playing with the mixture for gas mileage and performance balance. When I set it richer, gas mileage is worse and cold idle stays higher and takes longer to settle to 950ish. You would need to get yours tested to know for sure. Based on all the videos you have posted, your car seems to be greatly improved and chasing some numbers/behavior viewed as perfect may be time not well spent.

One important point that I neglected to make; I found that I had to adjust the idle up - to about 1000-1050 - in order to prevent the engine from stalling when engaging the clutch when coming to a stop during warm-up. I know it should be 950 +/-, but slightly higher suits it better. This was my original issue, but the FP now seems to be where it should be after swapping in Tony's calibrated WUR.

Also, one observation that I just made - while idling, I removed the oil cap, but did not sense a drop in RPM's. This is now puzzling to me. I have no clue where there may be a vacuum leak, if such is the case. One year old air box, hosing appears to be good ....

Thanks for your interest and feedback throughout this thread, SkiVT & pmax ... and of course, Tony!

I added data to post #75 - shows the huge difference my WUR vs. Tony's calibrated WUR

Jason

Jason

On the mixture: the only reason I was bringing it up is becuase it is one of the last things to confirm. The list includes wur pressures, spark, etc AND no air leaks. You stated no air leaks in the third post. If that is now an unknown instead of a "confirmed, tested", please ignore me for now.

Overall, it looks now like you had a wur significantly out of spec, TTV lines incorrectly attached so immmediate vacuum to wur, and unconfirmed airleaks. The engine still started and ran. I would guess someone made some adjustments to allow that to happen......

Keep at it, one testing item at a time.