Need More CIS Help, Please

[T77911S]

yea, i saw it.

60's, i had to rub it in. but its raining, had to drive the KA KA(old, ugly, runs rough etc) truck this morning.

[scarceller]

These may help, factory specs for CIS 1977 and (1980 with O2)

77


80

[Paulporsche]

Thanks, Sal.

What I'm wondering is why does the chart only go down to 10C? If someone set their ccp @ say 1.7 @ 10, would it show up as 1.3 @ 0?

[scarceller]

Originally Posted by Paulporsche

Thanks, Sal.

What I'm wondering is why does the chart only go down to 10C? If someone set their ccp @ say 1.7 @ 10, would it show up as 1.3 @ 0?

Paul, not sure but my guess would be that the chart is simply to test the CP between those temp 10-40c I suspect that the CP will go lower at 0c. Simply I think the charts are for test purpose and indicate that testing should only be done between 10-40c

[Porsche_monkey]

Originally Posted by scarceller

Paul, not sure but my guess would be that the chart is simply to test the CP between those temp 10-40c I suspect that the CP will go lower at 0c. Simply I think the charts are for test purpose and indicate that testing should only be done between 10-40c

That's one possibility, the other is that it doesn't need to be any 'richer' to start regardless of how far below 10 C it goes, and the control pressure may not change much below that temperature. Either way those should be your calibration points, somewhere around 10C and 40C.

[Paulporsche]

P_M,

Agreed.

TEST RESULTS 2 Apr 09 2:45 pm 13C vacuum line attached

Cold CP .3 bar Should be 1.5 bar
After 3 min .7 bar
After 5 min 1.0 bar
After 7 min 1.3 bar
After 9 min 1.3 bar Warm cp should be 3.4 bar

CONCLUSION

The cold cp is set over 1 bar too low. The control pressure does rise, but only by 1 bar, instead of the spec 1.9 bar. Whether the ccp was originally set too low, or the amount of vacuum produced by my engine is different from the rebuilder's bench I don't know.

I now have to fit the adjustment screw to the cold cp plug, raise it about 1 bar, and retry. I may have to then knock the warm plug down to raise the warm cp as reqd. Had to stop for now and let the garage air out. Phew that's rich!

BTW residual pressure held @ 1.5 bar for 10 min (min 1.3 spec)

[boyt911sc]

Originally Posted by Paulporsche

P_M,

Agreed.

TEST RESULTS 2 Apr 09 2:45 pm 13C vacuum line attached

Cold CP .3 bar Should be 1.5 bar
After 3 min .7 bar
After 5 min 1.0 bar
After 7 min 1.3 bar
After 9 min 1.3 bar Warm cp should be 3.4 bar

CONCLUSION

The cold cp is set over 1 bar too low. The control pressure does rise, but only by 1 bar, instead of the spec 1.9 bar. Whether the ccp was originally set too low, or the amount of vacuum produced by my engine is different from the rebuilder's bench I don't know.

I now have to fit the adjustment screw to the cold cp plug, raise it about 1 bar, and retry. I may have to then knock the warm plug down to raise the warm cp as reqd. Had to stop for now and let the garage air out. Phew that's rich!

BTW residual pressure held @ 1.5 bar for 10 min (min 1.3 spec)

Paul,

What were the system pressures during your test? I'm still cannot understand why you're having so much problem in your troubleshooting. If I were you, I would take the offer by someone about sending you a good working WUR. Just for heck of testing and finding what's going on in your set-up. A good working WUR (0-438-140-045) will deliver the spec you needed.

If you recall my PM to you about your style of troubleshooting and told you only time will tell how effective your's would be. There's nobody I know in this forum that has encountered so much trouble in fixing a CIS problem like you have. You have done so much work last fall and I commend you for that.

I have a spare CIS unit (fuel distributor and air box) I could lend you. Or a simplier arrangement would be to find some CIS spare components locally for the experiment/test. Since you have been very persistent in using your customized 'spec', instead of finding why the accepted spec's don't work in your case is like re-inventing the wheels. You are making it very complicated by having your own 'spec' (actually out-of-spec) unless you had a successful and proven result. Keep us posted.

Tony

[jonbot]

Hey guys, a little late to the game here.

Get ready for an earful

First, I claim to be no expert, but have logged countless hours working on my system, and I've got it working rather well for all conditions.

Paul, it sure sounds to me like some other piece of your system is "failing", like maybe something we haven't considered, like a crack in a vacuum hose up by the brake booster, or a crack in the vacuum canister, or a bad oil tank cap.

If you're thinking there's a crack in your air box, there's only two sure ways I can think of to really check if the air box has a leak:

1) Fabricate some plates to block all orifices of the air box, then pressurize the box with air, and submerge it in to a tub of water. (I've seen this done somewhere on this forum)

2) Use one of the smoke machines mechanics have in their shop. (At least this method will not require removing the CIS system from the car, and could also show any vacuum lines that are leaking.)

Also, another approach to consider is that running a lower than spec'd control pressure means the plunger in the fuel distributor faces less resistance as the incoming air pushes it up, meaning, the lower the CP, the more fuel you're introducing to the mixture. It seems to me that the only way a car could handle this type of richening up is if you introduce more air to the system, ie: (what Tony has told me multiple times is one of the main problems with CIS) vacuum leaks. It soundslike air is getting in to your system somewhere, and the lower CP WUR is attempting to deal with it.

On top of all you've tried, one thing always rings out in my head from all the CIS literature I've read: The basic primary function of any CIS system is this: cruising along at part throttle, with a fully warmed up engine. CIS tuners use this scenario as a starting point. Any other conditions a CIS system may experience, ie: cold start, warm start, fuel enrichment at WOT, etc...etc... can only be handled by the CIS with the aid of additional components, ie: CSV, WUR, Fuel Accumulator, AAV, etc...etc.... So, the theory is to get the pressures all in spec, and get it running well for a fully warmed up engine. If the system will not even do that, then you need to find out why, and focus on that. This should be used as a starting point, and once that works properly, then deal with all other conditions after that, ie: cold start...etc...etc...

Good luck man!

[Porsche_monkey]

Originally Posted by Paulporsche

I now have to fit the adjustment screw to the cold cp plug, raise it about 1 bar, and retry.

Do have the equipment to do this? PM me if you need help, I have a machine shop at my disposal, and I have done this mod a few times.

[Paulporsche]

Tony and jonbot,

I appreciate your comments and encouragement, but I think I would like to clarify something. There are 2 reasons for the seemingly lengthy trial period last fall and this spring. I was trying several WURs, including one that was almost brand new! Part of my procedure was to weed out the WURs I had on hand and determine that they were bad. How could I determine this w/o testing them? So I wasn't just trying to solve the running problem, I was identifying which of my stock of WURs was actually good. I don't see using a nearly brand new WUR, and finding out there was a problem, as poor technique. Likewise w/ the others. One had been working fine on another car prior to my trying it on mine. The testing procedure was 2fold: testing both all the WURs and my car.

Now, the 1980 WUR was actually working correctly and in spec, but, as you noticed, produced lean symptoms. I agreed w/ you and others that this pointed to a vacuum leak(s) which we couldn't find. I admit , however, that we did not use a smoke test, which I may still do, and which still may show up a leak. It's possible also that since this is a non vac WUR, that could be the cause of the problem, but I recall a thread or post by Souk in which he was using a non vac one on a non lambda system and was OK. If you remember, my tests were producing lean popping @ idle. The reason I didn't have a smoke test done was because I didn't have a source for one @ the time, was rushing off to a trip to CA, where I was able to get the WUR rebuilt, and then was rushing to get the car back into the garage for winter, which came about a month early last year. All this while trying to earn a living!

As far as persisting w/ my custom spec--all that entailed was resetting the newly rebuilt one to that spec, running the car part of a day or so, and then putting it away for the winter. The car hadn't been run at all from mid november until about 10 days ago. So it may seem like I've been testing and retesting or driving a malfunctioning car for 4 months w/o resolving the issue, but that's not true. I'm just restarting the procedure now.

The WUR I'm using now has been rebuilt and at least seems to be working, although, as I mentioned, has cps that are too low, lower even than the "customized" specs I came up with. My next step is to try to go back to the spec settings and observe the start/run conditions, which I'll report. As jonbot, yourself, Ty and others have pointed out, the stock specs produce the correct relationship between cp, sensor plate height, and mixture.

If I had a known correctly working 045 WUR @ the time I certainly would have used it for testing. As I said I had 2 used ones, one nearly new '80 one, and one from an Audi, and had to find out if they were working or not.

I also had a "theory" that my 95,000 mi higher compression engine somehow required a different spec from stock. This may be totally incorrect. I'll let you know once I find out.

My system pressure BTW was 70 psi, which is good. As of last fall, the injectors seem to be flowing fine.

Don't get me wrong, I appreciate your comments. I just wanted to clarify what I was trying to do, which was more than just replacing a stock WUR on a stock engine.

Feel free to comment. Even though it may sound like I'm being defensive, I realize all your comments are intended to be helpful (and have been) and I am not taking them as a personal criticism.

Porsche_Monkey,

Thank you. I have done this w/ my other WURs. The only thing I didn't do was install the drift pin into the housing/plug to keep the plug from turning. I've found that scratching a witness mark into the plug and housing identifies the alignment, and that there is sufficient friction there to prevent the plug from rotating anyway.

[boyt911sc]

Paul,

I still could not comprehend to your resistance not to test a good working WUR. It is a fact that your customized WUR is having all sort of problem otherwise we won't be here discussing this subject. BTW, the 0-438-140-045 WUR will deliver the exact control pressures you've been looking for.

Now, after testing a good WUR and the problem is still there, vacuum maybe the culprit. Pressure test your system and avoid guess work!!! Either you have vacuum leak or not will be determined by the pressure test. This is a very old and primitive method of locating air leak/s better than propane or carb cleaner some people used these days.

Lastly, you need a vacuum assisted WUR and TTV. And forget for the meantime your old WUR. It may come handy someday but not this time. As I said numerous times, CIS troubleshooting is easy and fun as long as you don't have any vacuum or air leak/s. Good luck and keep us posted.

Tony

[Paulporsche]

Tony,

The rebuilt WUR IS IN FACT a 045, vacuum assisted one, correct for a non lambda '79 car, which is the same one I have had on the car for about 17 years, and has been w/ this engine about 20 years. It has been cleaned and rebuilt by a specialist fuel injection company. All the others I tested last fall have been relegated to the spare parts bin. I have referred to so many different ones, that this may have created some confusion here.

I'm going to (perhaps stubbornly) reset my newly rebuilt 045 unit to the correct specs tomorrow and have a go. My recent test proves that the thing has the wrong settings, and that the engine does not work @ those settings, which is no surprise. The CPs are too low and the engine exhibits too rich symptoms.

To my (perhaps clouded) thinking, a known good WUR, taken from another car and set correctly, or my reset, rebuilt WUR set and correctly working should yield the same results. I can't think of any reason why this would not be true. Since I've had the thing rebuilt and I can reset it myself, why not use it? If I used a known good one that worked, I would still take note of its CPs and then use them in my WUR. I am just eliminating the step of inserting another WUR that will have the same specs.

If the new CPs are achieved and the engine works, then fine. If the CPs are correct and the engine is too lean, then it seems almost certain that there is a vacuum leak somewhere as you and others have pointed out. Whether it is a correctly working WUR from others or a correctly working rebuilt one of mine shouldn't matter, should it?

The important factors here are 1. that the WUR is working properly and 2. that the CPs are set correctly, not whether it's mine or another's WUR.

I am not ruling out an air leak. There must be some reason why lower CPs seemed to be required last fall, and that seems to be the obvious answer.

I PROMISE that if I either can't get my "new" WUR working correctly, I'll get one off someone else's car and try it!

Also, if either my reset one or a temporarily acquired other one don't work, my next stop will be the pressure test. I want to get the car running so I can get it to the shop.

BTW, despite how it may sound via my posts, I AM enjoying the troubleshooting procedure, and, as I said, it really hasn't taken too much time. Actually, I have spent more time on these posts than I have on the tests! But that's OK. I'm not complaining. It is merely that a lot of time has elapsed since I did anything about it, since the car sits over the winter in a cold, drafty garage.

So here's my methodology:

1. Set the WUR to the right specs and observe
2. If the right spec cannot be achieved, borrow a know good WUR, install and observe
3. If the known good one produces a too lean condition have a pressure test.

You know I'll get back to you.

[Paulporsche]

Here's the latest:

Since the last test only netted a WCP of 1.3 bar, I knocked the large plug and raised the WCP to 2.4 bar. Since the engine was warm @ that time, the engine started great and warmed up further and revved very well. The ambient was 5C. After 10 min, however, the wcp had only risen to 2.45 bar. I knocked the plug a little further, but the WCP didn't seem to want to go up any further.

I then tried another start 2 hrs later w/ the same results. Ambient temp 5C.

I tried again an additional 4 hrs later. This time the engine needed 2 tries to start but ran very well in 4C temp w/ the WCP up to about 2.45 bar.

This morning I tried an overnight cold start. Temp 6C. The car started w/ 2 pops and ran. I shut it down and knocked the CCP plug down to produce a CCP of 1.4. The engine then started very well and warmed up smoothly. The WCP, after 10 min only rose to 1.5 bar. Engine temp 125F.

This seems to confirm what Tony and others have suggested: that my newly rebuilt, correct 045 WUR still isn't operating correctly. Since my troubleshooting actually had 2 components to it, namely to see if the rebuilt WUR was good, and to see if the WUR was the cause of the poor running, I am pretty sure now I have my conclusions. The only thing I don't know is why the "new" WUR isn't working right. Is it the WUR itself or something else like a vac leak, which has always been a possibility? At least I think I can confirm that the engine itself is fine.

My next step then is to obtain a known good, in-spec, 045 WUR from someone so I can try it on my car. If it works well, then I'll know the rebuilt one wasn't done correctly, and I'll have to get in touch w/ the rebuilder. If a known good one doesn't work right, then I've got more to do.

In the meantime, since I can get the engine to run reasonably well, and weather permitting, I'm going to be looking into finding and visiting a shop that can check for vacuum leaks.

If anyone can loan me a known good 0-438-140-045 WUR, and/or knows of a shop to do the vacuum test in the Toronto area, please let me know.

[scarceller]

Paul,

Not sure if you covered this, but have you verified the fuel pressure (system pressure)? I ask because if your system pressure is low I think the CP would also be low.

[Paulporsche]

Sal,

System pressure is 4.9 bar, which is fine.

[wswilburn]

Paul,

This is getting beyond my expertise, but I wonder if a problem with the fuel distributor could affect the CP.

[Porsche_monkey]

http://www.robinsonautomotive.com/

Talk to Kirk, he can do it. Dixie/Brittania

If you take your WUR apart it is pretty obvious how it works. And how to fix it. One shim adjustment (trial and error) and one screw IIRC.

[jonbot]

Hey Paul, no offense taken in the least bit, I know we're all on the same page; just trying to help you get your car sorted ... Maybe others with more intimate knowledge regarding the WUR can elaborate more on this, but as I understand it, all the WUR does is regulate the control pressure, right?

Here's the scenario:
About a year ago I had suspected problems with my WUR, so I hooked up the fuel pressure gauge, and stuck the gauge to the rear window so I could watch the pressure in the rear view mirror as I drove. The thing read perfect pressures, so I concluded the WUR was good. So, reflecting on my experiment, can one assume at that point, having viewed proper pressures, that the WUR is working correctly? Or is there some magical, unseen, fluid dynamics type thing that could be happening in the background that can still cause it to be bad, even though it displays the proper pressures on the gauge?

Not trying to steal the thread or anything, just thought this question might be pertinent

[Paulporsche]

Porsche_Monkey,

Thanks. I'll give him a call.

I've actually had 4 or 5 WURs apart since last summer. The pins and diaphragms look fine, the metal arm heats up, the resistance seems to be in the proper range. The connection has power.

Scott and jonbot,

The FD seems to be working correctly because the spray pattern and volumes seem OK. Also, when the CPs were near their intended levels in my latest tests, the engine ran beautifully. I just can't seem to get the thing to rise as it should.

You have a point, though, because SOMETHING is causing the WUR to stay @ its original levels. If I set it for cold @ 1.3 it only goes up .5 bar. But the engine starts beautifully and warms up perfectly. If I set it to 2.4 (which is as high as I went) the warm engine starts equally well and idles and revs beautifully. The CP only goes up .5 from there.

Vacuum leak? FD issue? I've contacted the WUR rebuilder and I'll contact P_M's guy.

[ossiblue]

Paul,

Just a thought (and it's been a while since I read this thread from the start so forgive me if this has been discused.) You have been adjusting the pin and arm side of the WUR which is the most suseptable to variations, but the diaphram side of the WUR is also "adjustable" if necessary. The whole diaphram assembly can be moved up or down within the housing. Perhaps you can tap the diaphram housing a bit higher and achieve the pressure increase you need.