WUR delete kit

[AlKidd]

There is a post thats a year or so old about the best plan for a 3.0 build. In it a couple brilliant members mention a WUR delete kit.

Ive searched and cant find anything else about it. Can anyone shed some light?

[fanaudical]

Is that the one where somebody installed a manually-adjustable fuel regulator in the cockpit?

FS: 930 manual fuel pressure regulator kit

[Arlo911]

I think you mean Ian Carpenter's (icarp) kit.

[Bill Douglas]

Originally Posted by AlKidd

a WUR delete kit.

Umm.

Subscribed.

[AndrewCologne]

Originally Posted by fanaudical

Is that the one where somebody installed a manually-adjustable fuel regulator in the cockpit?

FS: 930 manual fuel pressure regulator kit

Its IMHO a manually driven pressure regulator which btw also needs an AFR monitoring device for manually adjusting the pressure for the whole time while engine is warming up i.E. – but ... maybe I catched that approach wrong.

A WUR is one of the most reliable pieces of the K-Jet.
After 40 years its more than normal that 80% of the ones running out there need an overhauling.
There are cheap Repair-Kits available including all you need and finally after applying that kit in much cases you even dont need to readjust the pressure by knocking/pulling the plugs of the WUR.

[AlKidd]

Yes Ian mentioned it but the thread seem to die, other than Tony saying the car was wild to be in. Its peaked my curiosity more than a desire to change anything. Its always nice to know there are options.

Originally Posted by Arlo911

I think you mean Ian Carpenter's (icarp) kit.

[AlKidd]

Im not sure what it was built from. It was just referenced in the post. No pics or anything.

Originally Posted by AndrewCologne

Its IMHO a manually driven pressure regulator which btw also needs an AFR monitoring device for manually adjusting the pressure for the whole time while engine is warming up i.E. – but ... maybe I catched that approach wrong.

A WUR is one of the most reliable pieces of the K-Jet.
After 40 years its more than normal that 80% of the ones running out there need an overhauling.
There are cheap Repair-Kits available including all you need and finally after applying that kit in much cases you even dont need to readjust the pressure by knocking/pulling the plugs of the WUR.

[RarlyL8]

I don't get the point. Why would anyone want to manually adjust the fuel pressure on the fly? What PITA. Get an adjustable WUR and set it up right or maybe an electronically enhanced WUR if you have to get that last 0.01bar or enrichment.

[jjeffries]

CIS : so under-appreciated.

John

[safe]

The wur can be a giant PITA. Ive worked on a couple of 924s where you get it dialled in, works great for a couple of days, then the engine gets worse and sure enough the pressures are off again.
I was close to doing the manual WUR, but ripped out the entire k-jet for EFI and life has never been sweeter for the car. Starts every time, anytime, perfect fueling, 3 dimensional ignition timing. Its like Internet on fibre instead of a modem....
K-jet was gone from my 911 15 years ago.

[boyt911sc]

Originally Posted by safe

The wur can be a giant PITA. Ive worked on a couple of 924s where you get it dialled in, works great for a couple of days, then the engine gets wworse and sure enough the pressures are off again. I was close to doing the manual WUR, but ripped out the entire k-jet for EFI and life has never been sweeter for the car. Starts every time, anytime, perfect fueling, 3 dimensional ignition timing. Its like Internet on fibre instead of a modem....
K-jet was gone from my 911 15 years ago.

Magnus,

If you know and understand how the CIS works, you won’t have such problem. It is the lack of knowledge and understanding that makes people hate it. It is old and antiquated but still a very reliable and dependable fuel injection system. My ‘78 SC Targa still has the original CIS unit and starts anytime of the year. The car was a track car my son and I shared for many years until I stopped going to the track.

Anytime I want to drive the car, even after months of sitting in the garage under cover the car starts and ready to hit the road. I have owned this CIS car for more than 30 years now and the only time it was towed home was when I ran out of fuel. I thought I had enough fuel but the fuel gauge was not correctly calibrated. Since then, I don’t let the fuel gauge go below 1/8 capacity. BTW, I also have a Motronic toy in the stable.

Tony

[safe]

Originally Posted by boyt911sc

Magnus,

If you know and understand how the CIS works, you won’t have such problem.

Tony

I do know how it works.

[AndrewCologne]

Originally Posted by safe

I do know how it works.

So, just mantain it correctly, keep everything at factory specs and it works fawlessly and wont end up in a pita – many people including me have no problems at all – car starts and runs like a modern engine.

Here in germany when I see how many US SCs and ROWs are running totally out of spec and with components like WURs still coming with diaphragms which never have been taken care of or been changed in 40 years, then Im not surprised if they suffer from problems.

I'm here 100% with Tony. CIS is one of the most reliable systems from the 70s/80s and if you get into it and things work are in their state as they should be - alle will be fine.
If it would be that worse do you think Porsche would have it kept all the years in their cars leaving the factory? I guess no.

[safe]

Originally Posted by AndrewCologne

So, just mantain it correctly,

Thats the problem! But I have not owned my cars since they were new, so hard to do.

[boyt911sc]

Originally Posted by safe

Thats the problem! But I have not owned my cars since they were new, so hard to do.

Magnus,

You are a capable troubleshooter you simply had not found or attained the skill to test and calibrate the CIS components. Most people I know who own air cooled 911 were not the first owner including my self. I found my first 911 sitting in a gasoline station abandoned by the owner for more than 5 years. You don’t need to be the first owner of a CIS car to enjoy it or have a good running car.

To add to Andrew’s post, in ‘70~’80 CIS was the leading fuel injection system in the world used by biggest and well known automobile companies like Rolls Royce, Bentley, Ferrari, Mercedes Benz, Peugeot, Porsche, Volvo, etc. CIS is not exclusive to Porsche.

Tony

[Dr J]

Deleting the WUR would be terrible for drivability. The WUR does the warm up enrichment based on car temperature to make the car drivable during this process. This would be the “after-start” enrichment for EFI. But, beyond that, it also provides acceleration enrichment even after the car is already warm. Without these functions, the car will not drive well. Maybe you can get away with manually adjusting the warm up phase but not the accel enrichment function.

After going EFI and seeing all of the conditions that must be accounted for, and how being off causes drivability problems, I am most impressed by the design and function of the WUR, and how well it does its job, when is working properly.

[RarlyL8]

You cannot compare brand new EFI to a worn out CIS. Brand new or totally refreshed CIS starts and runs in all conditions just as good as EFI. EFI is only as good as the tuner and software, CIS is only as good as its components.

[mysocal911]

Originally Posted by boyt911sc

To add to Andrew’s post, in ‘70~’80 CIS was the leading fuel injection system in the world used by biggest and well known automobile companies like Rolls Royce, Bentley, Ferrari, Mercedes Benz, Peugeot, Porsche, Volvo, etc. CIS is not exclusive to Porsche.

Tony

The final and best version of CIS was the CIS-KE, which eliminated the WUR, the FV, the CSV, and the analog Lambda ECU.
The simple and key element of the system was the EHA valve controlled by current from a digital ECU.

https://en.wikipedia.org/wiki/Jetronic