Digital WUR UTCIS-V
 

Anyone running one of these?
Had William Knight build me an engine and now I am running lean at WOT.

Looking for some feedback and recommendations.
Have read all the posts here on Pelican (last one was 2016!)
Thanks

Trying to stay with CIS due to class restrictions.

In 2018, I posted this in response to someone asking about Unwired Tools in the 930 forum.

There's even more threads than that. Do a search if you really want.


So. Unwired's original design was to vary fuel pressure using a stepper motor. Some reported that it took "a few seconds" - like 2-3 - to move from one extreme to the other - so couldn't react fast enough to adjust fuel mixture. Some reported that they had 3 units - but the stepper motors only lasted 2-3 days each.

After a couple of years or so, Unwired gave up on stepper motors and went to using a fuel injector to trim control pressure instead (like SC and late-930/965 Lambda systems do).

Like they arguably should have done in the first place. I can't comment on how well this design worked - because they never sent me mine, and no-one with an malfunctioning original unit ever got the working replacement they were told they would either. AFAIK.

For the original units, many guys got units that didn't work, or didn't work correctly. One got one that didn't have the fuel hose clamped inside the box(!) - with the result that it filled up with has and sprayed the excess out of the enclosure seams like a firehose as soon as the pumps ran.

Impressive.

I myself was fairly happy (warmup, in particular seemed improved for me, as well as running around town) - until I checked the logs and realized that the unit read engine RPM as approximately 2X reality (pretty sure I'd have remembered hitting 8000 RPM during my 9:00 AM commute to the office in traffic - that simply never happened).

I screwed around for a week or two trying their suggestions (stock ignition, distributor, CDI etc) to "reduce the ringing" on their ignition pickup.

Nothing they suggested made any difference whatsoever - so I sent it back for repair at their explicit suggestion. After a few months, I started chasing up every 3-4 weeks or so. Last communication was Steve telling me an upgrade unit was in Shipping and going out to me the next day.

Yeh, you can guess the rest.

They've never responded to an email, voice mail or phone call of mine since, and I am by no means the only one. Even trying hard to give them the benefit of the doubt etc, Unwired Tools was "you cannot be serious" status with many about 10-12 years ago.

Hardware design and implementation was poor. Software was rudimentary. Quality Control was patchy. Support ran out of suggestions quickly, lied about shipping replacements (which they still owe me, more than 10 years later) - and stopped talking to multiple customers that they'd misled, deceived and owed units to.

Is that really a company you want to deal with at all, much less send money to? LOL...


PP user Reanimotion started a project in 2014 to control fuel pressure (and this mixture) via a bleed injector controlled by a Megaquirt (IIRC). Thread is currently 37 pages long @ 40 posts/page here: Digital WUR plus? ( FrankenCIS ).

Seems to be still aciive to this day, and I recall plenty of people saying positive things/posting tech info etc. Seems a far better route than sending money to a bunch of lying liars with questionable engineering skills to me.

I moved on to MoTeC. In retrospect, I couldn't be happier.

Spuggy, thanks for that.

Very complete explanation of what has been memorialized in various threads. I had a stepper motor version and can confirm the issues with that model. Eventually I went full EFI.

The problem may not be the WUR but rather the fuel distributor being maxed out. We typically turn up the flow rate on modified engines.

In my case, I can say for sure that the issue was the time it took the stepper to open and close the valve in response to changing conditions such as accel and decel.

How do you "turn up the flow rate" on a FD?

An overkill! Owner says still in business, though; https://dkubus.com/?product_cat=bosch-cis-and-cis-e-k-jet-and-ke-jetronic

Here's the latest "project" -*post #35; http://forums.pelicanparts.com/porsche-964-993-technical-forum/928847-ez69-solution-964-turbo-ignition-module-2.html

Would be good to know here too.

I thought that you could use shims in the FD to achieve this, could be mistaken though?

It's an old thread but.. you have a lot of information on this video about how the FD works and and the pressure relief valve change the fuel pressure

https://www.youtube.com/watch?v=0K-ZiSanREA

Also you can see where the valve is placed sur le FD. You may change your pressure by putting more or removing some washers but if I can give you an advice… dont do it yourself. You should contact Tony (boyt911sc), it's one of the most knowledgeable persons I talk to about the Wur, fuel distributor, etc. on this forum. You can ship you FD and he will do the mod you want to.

http://forums.pelicanparts.com/uploa...1752845297.jpg

I intended that as a rhetorical question because I don't think it will increase fuel flow. If you increase the SP by shimming the SP pressure valve, then when you put the CO meter in the exhaust (or use an AFR meter with O2 sensor, as I have installed on my car), you find the mixture is too rich. Then you adjust the CO screw CCW a little bit, which lowers the plunger a tiny bit, which reduces the fuel flow, and you're back where you started.

The "adjust the FD to increase fuel flow" sounds like BS to me. It should only meter the fuel flow to the air flow.

Peter,

The CIS fuel distributors the SC’s have adjustable flow rates. You can measure the flow rates of the six (6) ports using graduated cylinders with a fix lift of the sensor plate for 1 minute duration for comparative tests. As long as you lift the sensor plate the same as before, the flow rates for 1 minute remain unchanged.

However, if the flow rate screw is altered (+) for one of the ports, the next test run will give you 5 ports with the same old flow rates and 1 port with new higher flow rate, higher than previously recorded.

So if another port is adjusted (+), you will have 4 ports with the same old low flow rates and two (2) ports with the new higher flow rates. Finally, if you make adjustments to the six (6) ports using fix height for the sensor plate for 1 minute run, you can measure the new higher flow rates.

In summary, the Bosch CIS fuel distributors particularly for SC’s have the capability to increase flow rates by adjusting the fuel flow rate screw/s. The hardest part is getting the new higher flow rates more uniform.

Tony

Tony, thanks for the explanation. However, it appears to me that if you increase the flow rates by adjusting the 6 delivery screws, then you will be running too rich for the same air plate lift. So then one usually adjusts the CO screw to bring the AFR back into spec, which reduces the fuel flow back to where it was. Right?

Otherwise, you could enrich the whole range (i.e., increase the fuel flow) by adjusting the CO screw richer.