VW Vortex - Volkswagen Forum banner

1 - 20 of 63 Posts

·
Registered
Joined
·
2,611 Posts
Discussion Starter · #1 ·
I collected pictures from different places (Some of the pics are not mine, hope the owners don't mind me using them) and i finally was able to make my own FEM, the info i found was insufficient and i still had doubts so i'll add stuff of my own to make this easier.
What you'll need:
1- 1 Relay
2- 1K resistor
(or potentiometer to make it adjustable, i used a 5K potentiometer)
3- Female connectors
4- Tap connector
5- Male and female plugs for the temperature sensor








The pics are almost self explanatory of how to make it.
Basically what we're gonna do is get power from the WOT switch (WIDE OPEN THROTTLE) to activate the relay.
All you have to do is disconnect the coolant temp sensor (on 16V engines the temp sensor is located on the right side of the head) and connect the female plug of the FEM and the male plug on the ECU plug.
To test it turn the ignition on and activate the WOT switch, you should be able to hear the relay.
(MODS feel free to edit this for better understanding)


Modified by The_GTi_Art at 12:56 AM 6-10-2007
 

·
Registered
Joined
·
2,097 Posts
Re: How to make a fuel enrichment module for CIS-E (The_GTi_Art)

The 16V schematic (above) is a little like the first one I made up a few years ago for my 8V race engine...it switches in a resistor at a selected RPM and WOT (as opposed to whenever the throttle is WOT since going rich down around 2000-3000 is not productive). TT and Autotech offer something similar. The IC is a F:V converter. The fuel demand changes with RPM and load and it seems the open loop table for WOT in the ECU doesnt map this well (at least for a modified 8V and probably for any modified engine). The AFR, if using a fixed resistor inserted into the coolant temp sensor circuit, may only be right in one place in this case (one engine speed and load combination). It is better than stock enrichment as it does decrease AFR across the board, but not enough in my experience (using the values I have seen published in the 1500-200 ohm range). I saw hardly any measurable power increase on a dyno using the above resistor values floating around on the internet...AFR was in the 13.5-14.0 range on a good day. I needed a value of well over 2k for my modified 8V to get anything like 12.5-13:1.
A variation on that, and one I developed and used hillclimbing last year, is to calculate what a given engine needs for "enrichment voltage" at a typical load across the entire RPM range to reach 12.5:1. Then I created an RPM driven log-scale-like output to supply a suitable increasing-voltage-with-RPM to the temp sensor input of the "ECU". This input can be driven by a voltage from 0-5V (a warm coolanttemp resistor usually results in around 1V) or a resistance that pulls the built-in 5V bias down more or less like the temp sensor does. You can get closer to ideal AFR with a log-like curve that tries to correct for the WOT table errors (because of engine mods), but many engines will have a problem area that is hard to dial in since this method also does not actively correct for load. . My 8V counter flow engine, for instance, would go way rich at high RPM until the top end was heavily modified to flow a lot more air (head, intake and exhaust). It is a little complex to reproduce that particular demand decrease (for a near stock intake and header) in an analog circuit. When my engine (with a ported head, OEM intake and header) was using this design I could get the AFR into 12-13:1 up to 5500 but it would drop into the 10:1 range by 6000 which isnt good. When I improved intake and exhaust flow with larger intake runners and a tuned tube header the high RPM AFR improved.
This year I came up with a way to integrate my Innovate LM-1 (analyzer) or an LC-1 into the car so it manages WOT AFR based on WB O2 readings and adjusts WOT enrichment thru the cars temp sensor input to the ECU. It also replaces the stock NB O2 with a suitable simulation so only one sensor needs to be used in the car. This does a much better job of maintaining 12.5:1 across all loads and RPM. In fact the range is more tightly controlled than when the "ECU" is managing AFR at part throttle. My recorded log shows a range of 12.3-12.8 in competition from 3000-7000 RPM for the above engine at WOT in all gears and all loads.
If anyone is interested in building and tuning either one of the last 2 for themselves, drop me an email, and I will send you a schematic for the hardware. You will need a way to measure AFR beyond what a NB sensor can do while driving to properly tune them for whatever CIS-E engine you have. The log-like analog design will require fair analog circuit design skills to tune, and the LM-1 based design requires the LM-1 or LC-1 from Innovate Motorsports (duh).
I have also worked off and on with an enrichment method suggested by Innovate but have not overcome one problem that may be unique to the Bosch CIS-E. Their method is to use the Analog 1 out of the LM-1/LC-1 set to simulate a stock NB O2 sensor normally and, via a relay, switch in Analog 2 in its place at WOT (The WOT input to the "ECU" must be disconnected so it stays in closed loop operation). The Analog 2 output would be set to output .5V at 12.5:1 AFR but otherwise appears like a normal NB sensor. This works well on Bosch CIS-L engines from reports I have read but the CIS-E "ECU" sees this change as a fault and begins a 10's-of-seconds settling process that results in open loop operation for a while. I speculated the problem is the fact that the switched-in analog output will be registering 1v or 0v as it comes into the circuit since under normal NB profiles 14.7 and 12.5 would be at the extreme ends of a typical NB sensor centered to 12.5 and 14.7 respectively. To try to address the problem thus far I tried widening the "range' of the simulated NB sensors so there was some overlap but either my speculation as to cause is wrong or I havent programmed enough overlap to make the "ECU" happy.



Modified by wclark at 9:53 PM 6-25-2007
 

·
Registered
Joined
·
2,806 Posts
Re: How to make a fuel enrichment module for CIS-E (wclark)

Both of these posts are very good ideas- this should be tagged so they don't get lost.
 

·
Registered
Joined
·
3,627 Posts
Re: How to make a fuel enrichment module for CIS-E (ny_fam)

I totally loved the one I made. worked great. could definitely tell a difference at WOT.
http://****************.com/smile/emthup.gif
 

·
Registered
Joined
·
3,314 Posts
Re: How to make a fuel enrichment module for CIS-E (Volkswoot)

I decided to make one, and I used the wrong relay, I just grabbed a relay without looking and had gotten a normally open, with 87 and 87a being the same output.
I now know that this circuit requires a Normally Closed relay.
here's another link just for references sake
http://forums.vwvortex.com/zerothread?id=840484
if you buy a relay from an automotive store, make sure to check the relay schematic and grab one that is a normally closed relay.



Modified by BellCityDubber at 3:44 PM 4-3-2008
 

·
Registered
Joined
·
352 Posts
Re: How to make a fuel enrichment module for CIS-E (The_GTi_Art)

your first diagram is incorrect
it will make more power but the vehicle will always think that it is running colder than it is
when you go wot with that diagram you open the circuit and the ecu thinks the coolant temp is at minimal value and makes it go way rich
it may make more power but it is not djustable at all
you can replace the resistor with a rheostat and have n adjustable unit
the last one I made with parts from radio shack and pick a part
total cost $5
worked great
before it would get sluggish around 5800rpm
afterwards would run until 6300rpm

with the diagram shown here the ecu sees normal ect value at all times except wide open throttle
when the wot switch is activated the relay activates breaking the circuit
the signal then has to run through the resistor making the resistance higher
indicating cooler temps which means the engine gets more fuel
 

·
Registered
Joined
·
3,309 Posts
Re: How to make a fuel enrichment module for CIS-E (sciroccoboy16v)

This one here is off of timbo's site (the second schematic you posted):
I built it the other day - haven't had a chance to do anything with it yet though. http://****************.com/smile/emthdown.gif


 

·
Registered
Joined
·
3,309 Posts
Re: How to make a fuel enrichment module for CIS-E (GoKraut)

Going to test it tomorrow....
I finished up the harness.
This works off of a minimum RPM (and WOT)
It has to have both criteria met before it works. That way you don't have the all or nothing effect so many complain about. I'll post up a more advanced version with adjustable enrichment when I get that far...
 

·
Registered
Joined
·
2,097 Posts
Re: How to make a fuel enrichment module for CIS-E (GoKraut)

It looks like the chip being used is the 2907/2917 8-pin version. If this is the case be aware that this one has the input referenced to ground. The coil tach signal is especially noisy around ground and I found false triggers made setting the RPM trip point almost impossible. I had to switch to the LM2907N (14-pin) and reference the input to about 1.2V positive (setting pin 11 to +1.2VDC) to get clear of the ground noise.
I used to use this chip to turn on fixed added enrichment at about 3500 RPM and still use it as a shift light driver. Here is how it looked then.


Modified by wclark at 11:06 AM 6-11-2008

Modified by wclark at 6:05 PM 6-11-2008


Modified by wclark at 6:08 PM 6-11-2008
 

·
Registered
Joined
·
1,052 Posts
Re: How to make a fuel enrichment module for CIS-E (The_GTi_Art)

SICK!!! how did it work out?? bloody genius!! http://****************.com/smile/emthup.gif http://****************.com/smile/emthup.gif http://****************.com/smile/emthup.gif
 

·
Registered
Joined
·
3,309 Posts
Re: How to make a fuel enrichment module for CIS-E (lilgreydentwagen)

Quote, originally posted by lilgreydentwagen »
SICK!!! how did it work out?? bloody genius!! http://****************.com/smile/emthup.gif http://****************.com/smile/emthup.gif http://****************.com/smile/emthup.gif


Walter's design worked like a charm.
 

·
Registered
Joined
·
1,052 Posts
Re: How to make a fuel enrichment module for CIS-E (GoKraut)

i picked up some 10k pots today from radio shack and i wanna make one of these things. i have some relays and harnesses i grabbed off a benz at pull a part... just cause their shiny
but i'm building a setup for my caddy that could put me over 200 whp on cis-e. what i'm wondering is how do i get it to enrich with this setup based on boost pressure? and how do i hook up a 6th injector on this to fire some more juice when i turn up the boost. i know these systems are fairly simple but i can't do it if i don't know what i need and i can't afford to be dumping money on expensive modules that are mass produced and over priced any links or suggestions, maybe even a parts list to build something like walter has would be very greatly appreciated http://****************.com/smile/emthup.gif
 

·
Registered
Joined
·
2,097 Posts
Re: How to make a fuel enrichment module for CIS-E (lilgreydentwagen)

Quote, originally posted by lilgreydentwagen »
i picked up some 10k pots today from radio shack and i wanna make one of these things. i have some relays and harnesses i grabbed off a benz at pull a part... just cause their shiny
but i'm building a setup for my caddy that could put me over 200 whp on cis-e. what i'm wondering is how do i get it to enrich with this setup based on boost pressure? and how do i hook up a 6th injector on this to fire some more juice when i turn up the boost. i know these systems are fairly simple but i can't do it if i don't know what i need and i can't afford to be dumping money on expensive modules that are mass produced and over priced any links or suggestions, maybe even a parts list to build something like walter has would be very greatly appreciated http://****************.com/smile/emthup.gif

Maybe someone has done what you are suggesting already and has an answer. Assuming that is not the case might want to try a few things on your own.
Almost all the modules and DIY enrichment that use the CTS input also trigger by the WOT switch on the throttle. That is fine for the most part but with the turbo is probably not the way to go since you will want enrichment at part throttle too. In fact you may want to disable the WOT switch completely depending on how what I am going to suggest works out.
Based on my observations of the 16V CIS-E in my car I believe the electronics uses the coolant temp resistance input all the time so when the engine is first started cold it targets a Lambda of around .85. The electronics pretty quickly increases that to lambda 1.00. My point is it might be possible and for a turbo, practical to fool the electronics at any throttle position to richen the mix by changing the CTS input.
A simple way to test the idea is to put one of your pots in place of the CTS sensor and monitor AFR at various pot settings and see if it does indeed force the mix to operate about richer points than stoichiometric.
If this is true then you go a couple ways to make it work for you. Either a simple switched-in pot, perhaps triggered by a pressure switch, or a voltage generated proportional to vacuum/boost. The first is simple but may not deliver a consistent AFR or one that varies appropriately with amount of boost and load. The second one is more complex but could smoothly transition fueling from a steady state lambda 1.0 at light loads to .8-.85 as load and boost increase.
The more complex solution also might require using a wideband O2 sensor and suitable conversion electronics. A narrow band O2 goes very non-linear either side of lambda 1.0 making control in the.85 range difficult and a wide band does not (but it must be scaled properly for the CIS-E electronics). My experience with this is mainly observing my CIS-E which IS fed by a suitably scaled wide band sensor signal.
 

·
Registered
Joined
·
1,052 Posts
Re: How to make a fuel enrichment module for CIS-E (wclark)

wow very informative. http://****************.com/smile/emthup.gif
any ideas as to where i might find a decently priced wideband? i was thinking about getting one anyway.
also is there a way i could maybe use a map sensor to control flow in place of the cts? i don't have the funds to dump in a stand alone right now and i really suffer from terminal uniqueness and would like to see how much power i can squeeze out of this system. i may have bitten off a little more than i can chew with this project cause time is of the essence. i'm moving in less than 2 weeks and i'm confident i can get this working but i wanna do it right so i don't break anything... and i don't wanna pay some greaseball tow truck driver 400 bucks to tow it either. i appreciate your help greatly. here's what i have as of now the pots, relays and everything i need to fool the comp. i'm running audi 200 turbo injectors. a volvo 7 somethinsomethin fuel pump k26 turbo stock wastegate (for that setup) and the jetronic computer/ knock box. i'm almost wondering if this setup will work without messing arount with the brains too badly? i just don't want to lean out in the top end cause that is where i'm used to driving these cars and i don't wanna blow any holes in my pistons in the middle of bfe where i'm moving to
 

·
Registered
Joined
·
2,097 Posts
Re: How to make a fuel enrichment module for CIS-E (lilgreydentwagen)

In 2 weeks, unless you can spend all that time on this and have a solid electronics background you are biting off too much to get done. Assuming you will go with a wideband anyway (even if you dont initially use it to drive the CTS input)...
You need to define "decently priced". I would go with the Innovate Technology LC-1 at about $200. http://www.innovatemotorsports...1.php
You can connect this to one of their AFR meters, or to a PC/laptop for monitoring, logging and tuning. It has 2 programmable analog outputs, one of which can be used to "simulate" a narrow band sensor for the engine electronics in place of the stock narrow band. Of course this output is going to be linear across a wide lambda range rather than switching rich/lean like a narrow band around stoichiometric. My experience with the VW version of the KE-Jet for the 16V is it is OK with the more linear input (scaled to the .1-.9V range of a NB) and it manages the AFR with less of or the same lean/rich switching that is exhibited with a NB depending on how steep you program in the lambda versus voltage slope out of the LC-1. The second analog output can be programmed and used later on to feed a 1-3V signal in place of the CTS sensor when you want to drive the lambda to a new value. This could be anything from a fixed voltage in place of a pot to a voltage that varies based on actual measured lambda to help the ECU maintain an enriched value you want.
Point of fact. The CTS sensor or a pot loads down the CTS input to the ECU to create an input voltage. The input of the ECU is internally tied a 5V level thru a 5K resistor, so an infinite value of load resistance yields 5V, 5K ohms external load yields 2.5V, and 0 ohms yields 0V. You can easily substitute a controlled external voltage source capable of sourcing at least 1ma (or more accurately sinking 1ma). I have found the normal "warmed up" voltage with the CTS sensor connected is about 1.08V. I have also found that with my both NA 16V and NA 8V before that I needed no more than 2.5V to drive the lambda to .85 at any altitude, RPM and load.



Modified by wclark at 1:53 PM 9-4-2008
 

·
Registered
Joined
·
11 Posts
Re: How to make a fuel enrichment module for CIS-E (wclark)

Im am intrested in the specific settings you used with your LC-1, and how the motor responded. I have installed a spare LC-1 in my cabby but it had a bad sensor so am awaiting a new one.
 

·
Registered
Joined
·
2,097 Posts
Re: How to make a fuel enrichment module for CIS-E (fartech)

I will check where they are right now and post them sometime today along with comments. By the way I am using an LM-1 because I wanted the extra features.

I have the "O2" sensor output set to: 1.0V.85L .10V/1.15L
And I have the CTS drive set to: 1.0V/.80L 3.0V/.93L
My experience is that narrowing the Lambda range on the "O2" output tightens up the control of AFR a little.
With the CTS output I experimented a LOT with settings. I found a range of about 1-2.5V worked well for my 8V and 1-3V works better for the 16V. The Lambda values were chosen to be roughtly equidistant from the target Lambda at WOT. When connected, up this creates a feedback closed loop that actively drives Lambda. One problem with it is that if you try to set the amount of "feedback" (the slope of the output) to steep the CIS-E "system" will oscillate - overshooting the target Lambda repeatedly, especially noticable when there is no engine load (such as testing in the shop). Decreasing the slope of the output slows the system response (allowing more variation in Lambda) but it prevents the oscillation. Under load (in my case Vt. hilllcimbs, which tend to be mostly WOT and 10-20 degree grades) my data shows an initial overshoot into the .8 range as the WOT switch activates but that lasts only a couple 10ths of a second then it shows pretty smooth control around .86 until I lift (and the WOT switch drops out), then the Lambda goes lean or rich for a moment depending on whether the throttle is closed or partially open - that part is up to the ECU - and it works its way back toward 1.0.
fartech - PM me your email and I will send you a log (Logworks) file from one of my runs at the last hilllcimb. As they say a picture is worth a thousand words.


Modified by wclark at 9:22 AM 9-5-2008
 

·
Registered
Joined
·
1,052 Posts
Re: How to make a fuel enrichment module for CIS-E (wclark)

wow very informative. http://****************.com/smile/emthup.gif
any ideas as to where i might find a decently priced wideband? i was thinking about getting one anyway.
also is there a way i could maybe use a map sensor to control flow in place of the cts? i don't have the funds to dump in a stand alone right now and i really suffer from terminal uniqueness and would like to see how much power i can squeeze out of this system. i may have bitten off a little more than i can chew with this project cause time is of the essence. i'm moving in less than 2 weeks and i'm confident i can get this working but i wanna do it right so i don't break anything... and i don't wanna pay some greaseball tow truck driver 400 bucks to tow it either. i appreciate your help greatly. here's what i have as of now the pots, relays and everything i need to fool the comp. i'm running audi 200 turbo injectors. a volvo 7 somethinsomethin fuel pump k26 turbo stock wastegate (for that setup) and the jetronic computer/ knock box. i'm almost wondering if this setup will work without messing arount with the brains too badly? i just don't want to lean out in the top end cause that is where i'm used to driving these cars and i don't wanna blow any holes in my pistons in the middle of bfe where i'm moving to
 

·
Registered
Joined
·
1,052 Posts
Re: How to make a fuel enrichment module for CIS-E (lilgreydentwagen)

ok. so i got a few things out of the way still haven't gotten the truck running i'm trying to find adapters for my fuel injectors unfortunately for me i can't modify my lines to make the audi ends with the correct 10 x 1 female connectors to work on my stock lines so i may bag the idea for now and run stockers with a 6th injector with a boost switch set to kick in at 5 psi to activate the injector. also i have an fpr from a saab turbo that i think is set to 2 bar... i could be wrong but it will piggyback the stock fpr with an adapter then t off to the 6th injector. color me crazy but it might just work till i can afford the lm-1
 

·
Registered
Joined
·
11 Posts
Re: How to make a fuel enrichment module for CIS-E (wclark)

Thanks for the log file! I have gotten mine installed in the cabby.
I set the LC1 to: 1.1v=13.1afr and .103v=15.53 & 1/12sec averaging.
Stock settings and no averaging made the cars AFR swing too much and stay richer. The settings above netted me an AFR that only varied +/-.1AFR at an idle. I still have to do some more testing in a cruise state. http://****************.com/smile/emthup.gif
 
1 - 20 of 63 Posts
Top