Flow restriction at the return line........
 

Jim,

The Bosch number for the WUR is 0-438-140-xxx. The last 3 digits identify a specific WUR. You still not have identify your WUR nor the FD. The picture of the WUR you posted is not used in 911 engines. That's probably from a Volvo or Saab or whatever.

For you to get a 100 psi. fuel pressure in a CIS means a restricted or blocked return line. A typical CIS system fuel pressure is between 65 - 75 psi. with a single FP. So anything that is greater than the system pressure (determined by the primary valve setting in the FD) means flow restriction going back to the tank. Even a totally clogged WUR could not produce a pressure higher than the system fuel pressure.

I will bet my money that you have a blocked return line. Don't expect any chance of running this engine until you are able to correct the fuel flow to the tank. Do you understand how the fuel circulates in a CIS? It would take a couple of mins. to test and confirm your high pressure problem. This is how easy and simple to determine the culprit.

Tony

This is your problem.......
 

Jim,

You have a bad FD. I thought you said earlier that the FD was recently rebuilt!!! Who did the rebuild? The primary or return valve inside the FD is not working to release the excess fuel pressure.

Tony

Tony,

Thanks for the help! I keep coming to the same conclusion, it has to be the FD. and yes it is a newly rebuilt one, as well as my oriiginal one. Is it likely I can fix this issue myself? can these vavlves be cleaned out or replaced?

WUR # is 0 438 140 045

FD # is 279973 729

Thanks again!
Jimhttp://forums.pelicanparts.com/uploa...1463318555.jpg

Bosch ID numbers.......
 

Jim,

The correct Bosch ID number is the printed numbers on the tag. Look very closely at different angles and you will see these numbers. The ones you are reading is the stamped or lot ID and serial number. It should read like 0-438-100-xxx.

Could you post the picture of the actual WUR you are using showing the numbers? Thanks.

Tony

OK when I look closely at the label on the FD I see 0 438 100 031 but the ones look like they could be 4s really tough to see.

http://forums.pelicanparts.com/uploa...1463343279.jpg

WUR calibration........
 

Jim,

What have you been doing with this WUR? The peg is driven down too deep and about to fall in and the disk is about to fall out!!!! There is no way in the world you could make this WUR work at this condition. Do you know what you are doing? If you do, you are doing it all wrong.

When I first saw the picture of the WUR you posted, my first reaction was "what was he thinking?" This is the third time I composed a reply to your thread. The previous two (2) were deleted. I was shocked to see your work and still wondering if you have what it takes to follow instructions.

All I could say at this point is wow!!!!!!

Tony

Tony,
You asked for a picture of the WUR for the numbers. I have taken it apart and put it together several times now. I did not think it would work in this state, but I did need to see if it had any affect on the pressure, which it did not, no matter what config I tried. So yes, I drove the peg all the way down, just to see if I could get ANY change in pressure, it was an experiment, a test. I am desperate at this point, as I have been working on this for a long time and cannot seem to get the pressure down. its just a pic for the numbers. If you can help I would appreciate it!

In terms of 'what was he thining" I was thinking I have to try to solve this issue. Its not behaving as predicted and I need to test it to figure out exactly what is wrong.

Jim

Hey Jim,

My 2c from a relative noob (maybe only worth 1c) but what worked best for me was:

Do an air pressure test to see where the air leaks air. I guarantee your injector seals and seats will be leaking if they are old. Your airbox is probably blown too if it's the original one. All the vac hoses and rubber bits will be crusty.

After air test and fuel pressure test I pulled all the components out and made an inventory of what I had e.g. remove WUR, FD, FV, AAR, AAV, decel, injectors to make sure they were in fact present, correct and matched to the car. The systems are so open to people screwing with it. This will just put you in circles. People have been hacking and mix/matching for years. It doesn't work. My mixture was cranked so high the system could not compensate. I had a WUR issue where my CP would not come up. The plunger had come adrift in the box. I think your WUR is frankly kaput and you need a rebuilt one.

I then tested every single one of these and verified that they operate within spec. I tested the lambda box though the diagnostic pin if you have lambda. FD and WUR can be sent to Tony for analysis/rebuild. He dishes out tough love but he does know what he's talking about :).

Clean and reassemble with all new/rebuild components for O2 sensor, lambda relay, WUR, airbox, seals, o-rings, injectors etc. Redo air pressure test and fuel test to verify rebuild. This was quite successful for me. The only issue I have now is a surgy grumpy cold idle on the warmup cycle but I think that can be quite easily sorted when I have the time to investigate properly.

Hope that helps.

G.

Thanks for the helpful advice G!

I am still thinking I have a blockage in the system somewhere causing the high pressure. Im gonna swap out the gastank and see if that solves the issue. IF not, then I will need to start from the very beginning as you suggest.

Thanks!
Jim

Keep it simple.......
 

Jim,

Pack and ship the FD and WUR to me. I will send them back to you with my evaluation. It would take me less than an hour to characterize their fuel pressure readings and what to do with them. I want to help you and you seem to be a determined person. You could do it yourself like what you are doing now. And may take you so much time and effort to get to the bottom of the problem/s. It is not how hard you work but how smart you do the job. Just take care of the shipping cost (postage) and get a good start.

You need a good working WUR,FD, and many more to be able to run the engine. Your immediate goal is to get the motor running. Once it is running, the rest is easy. PM me if you decide to accept my help. Wish you the best.

Tony

No worries Jim. Do yourself a favor and send the WUR and FD to Tony. Then you will have a baseline to work with. The baseline is very important with CIS. If the FD and WUR are not spot on it will never work properly.