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Reanimotion Reanimotion is offline
umop apisdn
Join Date: Jun 2014
Location: Brisbane, Australia
Posts: 558
Digital WUR plus! ( eCIS - FrankenCIS )

Before I begin, I'd like to apologise for owning a 928 and posting here but I see that the UTCIS and similar modifications to the K-Jet seem to be most frequently discussed here.

A properly adjusted and serviced K-Jetronic / CIS system is the preferred and cheapest way to go. The BL WUR seems to be the best adjustable option so far and still requires little modification to the rest of the car.

If you are crazy or there is a valid reason such as originality or historic racing classes etc. then this might be an option for you.

Refer to the bottom of this post for the current up to date project information and requirements including Install Parts List

Why FrankenCIS?, I'm not really sure other than it seemed like a cool but oddball way of getting programmable EFI in the old beast.

I've had a MicroSquirt in the car for a couple of years now with custom firmware to control the 996 instrument cluster and S4 fans amongst other things like the ClimaTronic head and Audi RNS-E. I've been following the MegaSquirt install threads on rennlist with interest and even collected most of the required bits to do the changeover when I pull the engine for a seal and hose refresh.

Then I started thinking the existing system is a bit crude but working well and VERY reliable, so what would I lose by changing to real EFI.
1. The existing base tune - I'd need to completely retune the car from scratch.
2. the almost atom bomb proof reliability
3. the factory look in the engine bay
Plus I'm quite OCD when it comes to a factory built look to things, meaning a lot of work to do it properly and "if it aint broke don't fix it!" should apply wherever possible.

Well after some research, I then chickened out and shelved the EFI plan as the CIS system is working fine, but the silly side of me then thought "Hey, what about a digital WUR?"
A few weeks of internet research later and it appears the small number of previous attempts by others have either had flaws in control or execution or failed to kick off.

I then looked at the wish list from one of the ex-users of the UTCIS
1) Instead of entering control pressure, it should use a wideband 02 sensor in a closed loop system. That way you enter AFRs instead of control pressures (which is ultimately what we are trying to control)

2) The control pressure should be measured at the DWUR and electrically sent to the "brain" (Mine has a thin fuel line that can be easily kinked)

3) Random loss of programmed values should be fixed.

4) Output a warning signal whenever AFR is say 0.5 points above the requested value.

5) Let the software import/export the maps as excel or csv or text files that way it is much easier to optimize your map

6) Let it auto-tune itself, given the AFRs of point #1
and the penny dropped - use the MegaSquirt family to control a properly engineered digital WUR.

I own a software company and an engineering firm so voila, we have a little side project

Now as this is a MegaSquirt based project, the firmware for the MS is being written to be basically hardware independent and the project is being run in the spirit of the MegaSquirt family i.e. semi open source / hobbyist. So DIY from junkyard or parts bin bits will certainly be possible, and even reviving a non-stepper UTCIS if you have one, therefore I will be posting this as a make-it-yourself type thread even though we will be producing and selling a really nice modular anodised metering block elsewhere.

The FrankenCIS concept works and is now operational on the bench, so what is it?

FrankenCIS is a software and hardware project to allow the MegaSquirt family of engine controllers to replace the Bosch WUR.
In its simplest implementation - mimicking the WUR by a temperature to bar map and closed loop pressure control. With optional interceptor like +- control of fuel mixture using the full mapping abilities of the MegaSquirt family.

More advanced implementations - the sky is the limit really. Spark and Idle control. Full fuel mapping. Closed loop wideband O2 control. Boost enrichment and or pressure control. and so on.
How are we doing it?

MS2Extra firmware has been modified to change a "Squirt per Rev" to mapped fuel pressure control on Injector1. The target pressure is taken from a new map representing the WUR basic bar/temp curve and then modified by percentage according to changes in the remaining tuning options.

What it needs:
- a pretty anodised metering block - or a late non-stepper UTCIS if you have one - or some hardware bits if you are going the boneyard / parts bin DIY route.
- sense the actual fuel control pressure, we do that with a digital pressure sensor in the metering block, but a simple bosch oil pressure sensor or similar will do the trick. (Boneyard bit #1) Do make sure whatever you use is rated for fuel, as a massive fuel leak under the hood is a very a bad thing.
- control the pressure bleed and therefore the control pressure, we do that with a standard side feed fuel injector in the metering block by modifying the open time at a set frequency in response to the difference between the actual and target fuel pressures, the longer it's open per pulse the more the fuel pressure bleeds of then the lower the control pressure. again an alternative would probably be a fuel pressure frequency valve from an early CIS vehicle with O2 sensor control (CIS-lambda and Boneyard bit #2)
from an early 80s VW something like this could be adapted too
- Engine Temp - a temp sensor bolted to the block or tapping into the engine coolant temp to will do nicely.
- MAP sensor - 1 bar rated for NA - 3 or more for turbo or charged applications
- Engine revs rpm output from the CDI to the Tach

What would be nice:
- RPM and Position - the good old green wire if you want to take over basic spark control, over that any of the available crank sensor options up to the 60 tooth flywheel would allow silly levels of resolution and control for spark and fuel. I'm personally going for a modified distributor with 24-1-1 VR as a compromise with a single coil.
- O2 sensor - narrow or wideband, for AFR target control. a wideband unit would obviously be better for range and to use the Tuner Studio semi-self tuning option. We will be using the LC-2 as it's one of the ones MegaSquirt already knows how to talk to.
- PWM Idle valve to allow the system to control idle speed - I'm personally having my staff make one to look like the original IAC
- TPS - basically the more sensors available to the system the better the control and tuning options become

A MicroSquirt or MegaSquirt II is the sensible minimum needed to control it.
(MS3 or MS3Pro if you are willing to do your own software mods and testing will give you a wider range of advanced toys including the CEL warning light option asked for.) no longer recommended

The good news is almost everything carries over to a full EFI system if you ever decide to crossover to the dark side (or is that leave the dark side)

additional from 23/9/14 >

Reference Install Parts List

MicroSquirt (tm) MicroSquirt Engine Management System (30 inch harness) or the longer 8' harness option MicroSquirt Engine Management System (8 foot harness)

FrankenCIS (tm) Metering Block #1 or #2
Injector - Delphi FJ10409 Fuel Injector (Single) For Dodge Chrysler Eagle 1993-1997 New Delphi FJ10409 11B1 Fuel Injector 4573062 4G1156 FJ208 | eBay
CP sensor - from Ahead Instruments (eBay store 100psi items - Ahead Instruments eBay Store)

Pressure Damper ( if using FrankenCIS #2 ) Denso 23270-62010 (xref to AIRTEX 3G1015 WELLS FD424 STANDARD MOTOR PRODUCTS FPD4 )
Gasket for above damper Toyota 23232-41081

MAP sensor - Denso
IAT sensor - BOSCH 0280130085, PORSCHE 99360611400 SEAT, SKODA, VW 058905379, FAE 33226
Engine Temp sensor - Bosch 996 unit
WBo2 - Innovate LC2
(to suit a particular application the four sensors above can be substituted with anything compatible with MegaSquirt)

Last edited by Reanimotion; 12-04-2014 at 07:52 PM.. Reason: Reference Parts List
Old 07-12-2014, 03:37 AM
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