CIS Revisited
 

Following up on my earlier post relative CIS troubles, I have made some progress.
I borrowed a working fuel dist., (FD) and also a WUR. Both were installed in my vehicle, vehicle was tuned and ran great. Had 4.7 bar system pressure and warm control pressure at 3.6 bar. Car drove well, started well, cold or warm...
In the interim, testing had shown both my WUR and FD were not operating correctly so I sent them out to be rebuilt. They returned and were finished in the most professional manner. I installed them this morning and fired the car up, 5.7 bar on the system pressure and 3.9 bar on the control pressure, with a 1.4mm shim washer. So I proceeded to diminish the thickness of shims until I had no washer shim. This was slowly done over the course of 5 tests. The final test with no washer shim, produced a system pressure of 5.15 bar and a control pressure of 3.8 bar. At this point I put in a new fuel regulator, Bosch, with no washer shim and the system pressure dropped to 5.0 bar and control pressure to 3.8 bar.
So how do lower the pressure further? I am shooting for a system pressure of 4.7 bar in which the car with the borrowed WUR and FD ran superb. Does someone make a outer spring that is shorter or less tension.
Really drawing blanks here.
Any help most appreciated.
Jeff

Ah you need to hear from Tony (Boyt911sc) from way downstate in Norristown.
Maybe you could PM him if he doesn't see this.
Can you provide a link to your previous post on this?

CIS troubleshooting.........
 

Jeff,

Why do you have to do all this testing when you had your WUR and FD recently rebuilt? When they are rebuilt, it should be calibrated too. Is your car a US or RoW spec? What are the FD and WUR Bosch numbers? Your WUR and FD were rebuilt and they should look nice and clean. And most important tested and calibrated. Yours were off spec. and you had to make them work? Who rebuilt them? Did you contact the rebuilder about your problem/s? Keep us posted.

Tony

The car is a stock, USa model with a CAT bypass.
The number on the WUR end in 090 and the FD number is 0438100077
Have reached out to the rebuilder.
Here is a pic prior to install of the rebuilt FD and WUR.

Thank you all for you help.
Jeffhttp://forums.pelicanparts.com/uploa...1512047452.jpg

I am also curious who did it. not because they may not have done it right but if there is someone besides larry doing them I would like to know who.

FD & WUR rebuilders.........
 

Ty,

You know him and he is an active member of this forum. I doubt he would acknowledge his involvement with Jeff’s FD and WUR publicly. Let’s give him the opportunity and the chance to air his side. He claimed to be a newly authorized Bosch FD & WUR rebuilder.

The information I got was a private message (PM) and will keep it that way. BTW, there are several outfits rebuilding Bosch FD & WUR aside from Larry, one in particular is in TX.




Jeff,

If your rebuilder would not fix the problem/s, send them to me and I will calibrate them for FREE. Consider this a X’mas gift from this forum. Keep us posted.

Tony

A favor to ask.......
 

Jeff,

Could you measure the heater resistance (Ohms) of the WUR at room temp. (70°F) and at 80°F and post these numbers? Thanks.

Tony

Tony, the WUR values are as follows:

70 degrees, 25 ohms
80 degrees, 10 ohms

from 70 degrees, I slowly heated the WUR with hot air, when it stabilized around 80 degrees I then checked for the value. Maybe not to scientific...

Thank you, Jeff

Any response from the rebuilder?
 

Jeff,

Any luck getting a response from your rebuilder? You spent a good amount of your hard earned money and should have received a properly rebuilt WUR and FD. Give him a call and send emails until you get his attention. Try your best to contact him and if you are not getting any response, time to send them to me. I will calibrate them and send them back to you.

BTW, why don’t you give him another chance and wait for 48 hours. If nothing happens good after waiting for 2 days then time to move on.

Tony

by any chance did you check your return line to make sure it is clear?
I was able to blow thru mine on my 930. full tank could make that harder


just curious if there is another rebuilder. I would be extremely shocked if larry did a bad rebuild.
it just seems odd that it would come back with hi pressure.

Read post #1........
 

Ty,

The OP was able to drive the car using borrowed FD and WUR. If the return line was clogged, no FD and WUR could make it run good. There was no problem with the fuel lines system. If you are really interested in knowing the rebuilder’s name, ask Jeff.

Tony

sorry, cant always keep all the details straight of every thread.

Rebuilt FD and WUR.........incorrectly calibrated.
 

Jeff,

Were you able to get the car running already? It has been a month since you had the problems with your newly rebuilt FD and WUR. Hope the rebuilder apologized to you for the inconvenience. Thanks.

Tony

Hope you get them back before spring........
 

Jeff,

Sorry to hear that your FD/WUR rebuilder has not returned them back to you. He has been in this forum posting and yet did not bother to chime in and acknowledge his responsibility. The least your rebuilder could do to you as a customer is to replace the badly calibrated FD/WUR with a new set or have them fixed promptly. You paid premium prices for his services and should expect a good one.

It is unfortunate that you are hesitant to mention his name and by doing this, you are NOT helping other members from getting into similar predicaments. I am sure you are not alone and there could be more people in same situation. Good luck.

Tony

Rebuilder’s responsibility.............
 

Jeff,

I appreciate you contacting me regarding your problem with your fuel distributor. Your FD-077 is out of calibration as you have found out. What I don’t understand is why are you doing all these repairs? You paid premium prices for the rebuild of your WUR and FD and should not be doing any of this fixing to make them work.

It is already springtime 2018 and these CIS components were rebuilt in November 2017. So what is the excuse of the “rebuilder” this time? Why would a CIS parts rebuilder sent out rebuilt parts that are not correctly calibrated? Not once but twice? Simply because the rebuilder does not care about the customer’s need. He got paid and sent you the rebuilt parts. End of story.

BTW, both your WUR and FD are out of calibration. You could help other people getting into similar predicament by simply identifying the rebuilder’s initials like AA or BB, etc. Wish you luck.

Tony

Newly rebuilt FD & WUR.........
 

Jeff,

I am done with the tests and recalibration of your newly rebuilt FD & WUR and sending them back to you. There is another thing you have to work with your rebuilder, the 6 micro filters were missing. See pictures below:

Your WUR-090 came to me with only 10 Ohms at room temp. and should NOT be given back to customer at this condition. Recalibrated it to spec. 26 Ohms @ 68°F. Picture below was taken @ 62°F after midnight (cooler basement temp.)
http://forums.pelicanparts.com/uploa...1525307951.jpg

Your FD is on the left with red paint. Mine is at the right of the picture. If you look closely the filters in your FD are missing. Both WUR and FD recalibrated.
http://forums.pelicanparts.com/uploa...1525307951.jpg

http://forums.pelicanparts.com/uploa...1525307951.jpg

I will be away traveling abroad by the time you get the FD and WUR and won’t be back till end of May. But would be able to communicate with you via email. Request your mechanic to measure the cold, warm, system, and residual fuel pressures and write them down.

Tony

Share your findings.........
 

Jeff,

As much as I like to help you, please share your findings and experience so others would have the benefit of learning and knowing what to do next time they encounter similar problem/s. While I had access to my emails, Pelican Parts forum is not accessible in Mainland China and was only able to visit this forum when we got in Hong Kong. In a few days, we will be back to LA and finally fly back home.

Your CIS problems were minor and easy to test but the lack of experience on your part made it more difficult but we finally sorted it out. If you will share with others how you got the engine to run and identify the culprit/s will help others in the future. We all make mistakes and I made a lot of stupid maistakes too. So you are not alone.

You did all the work and all I did was to guide you thru the procedures. Good job.

Tony

Tony is the master when it comes to cis and rebuilding the system. He’s done at least 6-8, maybe more, wur & fd’s for us. Perfect every time.

Tony, any plans for a CIS component rebuilding class? I know these things take much time and energy, but I'd drive down from CT for that. Best regards, John

Tony I am curious how you "recalibrate " a wur. Is the heating element not a fixed resistance ?
if its a trade secret I understand. I am really curious now though. I have a spare wur in a box so I'm going to check the resistance and temp as you did.

I'm not Tony, but I'll try to answer.

Take a look at this picture. I stole it from somewhere else on Pelican and added the notations. This looks like it might be an -090 WUR.

http://forums.pelicanparts.com/uploa...1527603802.jpg

"The Disc" is where most of the magic happens. The basic components are the input/supply line from the fuel distributor (FD), the internal diaphragm of "The Disc" and the output/return line to the FD.

The fuel pressure coming into the disc is the system pressure. This is the fuel pressure generated by the fuel pump. If you do the CIS fuel pressure test for system pressure, when you close the gauge valve, this is the pressure you're reading.

"The Disc" reduces the fuel pressure from system pressure to control pressure. There are two states for control pressure: (1) the cold control pressure (CCP) for when the engine is stone cold and (2) the warm control pressure (WCP) for when the engine is at normal operating temperature.

If you were to disassemble the WUR and look at the disc from the inside you would see there are 4 screws that hold it in place and a tiny little indention in the center. If you were to hook up the disassembled WUR with just the two fuel lines in place (and a fuel pressure gauge) and pushed up on the indention, you would see that by pushing on the indention you would actually be varying the fuel pressure. Inside the disc is an o-ring. Sometimes the o-ring fails with age. In the input fitting there is a metal screen. The screen can be clogged over time. To clean it, soak it in something like carb cleaner and then blow it out with air. Short of the o-ring failing or the filter clogging, I'm not aware of any modification that can be done to the disc itself to affect control pressure.

If you put little or no pressure on the indention of the disc, this would be the cold control pressure. If you applied a little more pressure until you reached a max value, this would be the warm control pressure.

It is important to understand something. When the control pressure is LOW, this makes the mixture more RICH. When the control pressure is HIGH, this makes the mixture more LEAN. Therefore, on a cold engine you want a richer mixture. Once the engine is warmed up, you want it to be leaner (not lean -- I mean "leaner" than rich). Basically, the WUR and the AAR act together to replicate the functionality of a choke - add a little more gas and air until the engine is warm.

So, to calibrate the WUR, you need 3 things:

1) the cold control pressure needs to be correct for a cold engine (based on ambient air temperature)

2) the warm control pressure needs to be correct for a warm engine so that you're not too rich or too lean at normal cruising

3) the rate that the bimetallic strips heats up should not be too fast or too slow. In general, it should take about 3 minutes to go from cold control pressure to warm control pressure. If the element warms up too fast, the mixture will be leaned out prematurely (before the engine is at operating temp).

To set the cold control pressure, the starting position of the bi-metallic strip arm is really critical. In the picture up above, I labelled "The Pin". To adjust the CCP start with the "guts" of the WUR removed. Use a hammer and a drift and carefully drive the pin down until it is flush with the outside surface of the WUR. This will remove the arm pressure from the disc and this should be the maximum warm control pressure.

Now re-assemble the WUR and hook up the fuel lines with a fuel pressure gauge inline. Run the fuel pump and check the pressure. If you take a drift and tap the pin down, the CCP will go down until you reach your desired value for your model WUR and the ambient temp. TINY amounts of movement will affect the pressure. If you knock the pin down too far the pressure will bottom out and you would be really rich on cold start. This is where you need to consult the graph for your WUR model. Check the ambient air temp (if in ºF, convert to ºC) and look up what the CCP value should be. That is your target. If you overshoot you have to disassemble the WUR again and tap the pin back down to the starting point and try again.

Once you have the CCP set, plug in the electrical connector and time how long it takes for the control pressure to reach it's max and record the max value. This is the warm control pressure and it means that the bi-metallic strip is putting pressure on the indention of the disc. The WCP should be within the range specified for the model of the car. Typically, this value should be in the same range as the max CCP value on the chart.

Take a look at this picture too. It's actually a picture of the mod to make the WUR adjustable (but only to raise CCP), but it's helpful to understand how the WUR works.

http://forums.pelicanparts.com/uploa...1470900719.jpg

If you look at the CCP graph in the Bentley, the range of temps is 10ºC (50ºF) to 40ºC (104ºF). Any temp lower than 10ºC/50ºF the WUR treats as the same CCP as 10°C. And any temp greater than 40ºC/104ºF the WUR treats as a fully warmed engine. So the variability in the CCP is only between these temp ranges.

The problem with adjusting the CCP is that you're hoping that by calibrating the CCP at one temp it will be set for the right CCP at other temps. This is why some people complain about seasonal differences on how the WUR operates. Let's say you set the CCP perfectly for a nice spring day. But maybe in the cold of winter you might be too rich or too lean from what the CCP should be. The WUR is an analog device and it has some limitations that come along with that.

Hope this helps!

Well put Tony. I'll take it a step further and suggest the full identity be made known. We all like to promote people & companies who do great work. Those who are not doing so should be recognized for the caliber of their work as well.