View original topic: Info on Tiico ECU's from FAS Page: 1, 2, 3  Next
Californio Thu May 02, 2013 10:57 am

Just an FYI, for those of us driving vans with Tiico engines.

I had a long talk with the folks at FAS yesterday, and it turns out that there is a flaw in the original Motorola ECUs shipped by Remco in South Africa. A pretty serious flaw, at that: the original ECU doesn't pay attention to the O2 sensor voltage, so there is no way to get to an ideal mixture, either at idle or at speed. Most of the time, the engines will run lean, resulting in the obvious problems--lower power, hot running, etc.

This is for the "A" version of the ECU that Peter was importing in 2000 or 2001.

The reason for this is that South African gasoline has a higher octane rating than ours, something like 96 at the time, and the higher octane was able to mask the lean running condition. I'm not an expert, just going by what I was told. Here, the engines run consistently lean. In my case, this has resulted in an exhaust down pipe that gets so hot it blows out the OME shock on the driver side, about 3" away. Happened twice and I never understood it. It also burns up the downpipes themselves, a common complaint among Tiico owners.

There is no way to fix this other than installing a new ECU (I think they're on the fifth generation now) along with a new A2 fuel rail and most important, a 4-wire O2 sensor.

I'm hoping this will help someone trying to improve running conditions for their Tiico in the future. The information I was given is not available anywhere else, even on the Yahoo Tiico forum or, to my knowledge, VW Vortex. It has answered a lot of questions for me, and I'm going to try the new ECU. Will report back when I've had a chance to compare.

The people at FAS are very helpful.

joseph928 Thu May 02, 2013 11:14 am

:bay_blue: Thanks this good to know, I'm lucky mine runs like a race car! :D

Ryan Alfonso Thu May 02, 2013 11:37 am

No kidding? This really hits home. I've just fried my second Bilstein because of this heat soak issue. Maybe it's cuz I drive it like a race car. No really, I do. :) Wanna drag race? Calling Chris now...

Thanks for the 411.

schenks13 Thu May 02, 2013 11:55 am

That's good info for any Tiico owner to have, but there is more....

Jon (FAS owner) did post on the Yahoo Tiico Group about the ECU issue/history. I've cut and pasted it below for those interested that do not have access to that forum. I did edit the ending of the write up that talked about a shipment of ECU's from South Africa (that's old news...they've been in stock at FAS for a while now).

The posting:

Bosch:  SA MP 9.0 Motronic Fuel Injection System

Peter B. from Tiico called me in November of 1999 in a complete panic…he was bombarded with calls noting serious cold start issues, engines flooding and copious amounts of black smoke belching out the exhaust once they did start.  My answer was: "sure, I bet they are…we have a bunch here…and they will continue to be like that w/o an 02 sensor.  The 'open loop' system was not designed properly for what was needed in North America." Of course he wanted an easy magic fix such as replacing the fuel injection coolant temp sensor like all the North American Digifant injected models, but, that would not be the case…and so, it began.

In the previous post I spoke about the S. African "Volksie Bus" as being carbureted off of the production line.  Because of this, they never injected the in-line Vanagon (T3) in SA until they went to the 5 cylinder Audi platform.  Realizing that a carbureted conversion could not be sold in this country and even come close to passing smog... Peter B. and Remtec decided to use an injection system produced in South Africa based off of the "City Golf", or what we call the Rabbit, because the engines were almost identical and manufacturing would be simple based upon their current "City Golf" production numbers at the time.  The City Golf was everywhere in SA and like the Fox in other countries, their on-board operating systems were  produced as an inexpensive third world budget system.   To make things worse… at least the Fox in North America was designed with an 02 sensor and fully mapped cold start capabilities… that was not the case with the City Golf or earlier Tiico's.  They had neither.
That first winter we ran straight in to it all in one week's time in November in Northern New England a day before the call came from Peter.  The lot was full of as many no start Tiico's as ones we were getting ready to install.   We had him send us an ECU pin out for the system.  All similar VW Bosch operating systems that run Motronic, mono-Motronic  etc., had their data wire going into the ECU on pin #38.  So we added a 3 wire 02 sensor and ran a shielded Data wire into pin #38.  Immediately, the system reacted as it would in closed loop!  The vans started right up cold, the idle hunted a little but not much worse than any Golf/Jetta and they were not belching black smoke and they now ran decent at 25 degrees Fahrenheit.  We observed at start-up cold the 02 sensor voltage remained constant at about .4 volts and then as the vehicle warmed up… even better it started to oscillate normally between .2 and .8 volts!!

The following week Peter asked me to join in on a conference call with him and one of Bosch SA's Engineers.  The guy at Bosch told us we must be mistaken.  He supposedly had personally written the operating program we were discussing and that it was not capable of doing what we were describing!  We told him we verified the results on 4 different vehicles with our oxygen analyzer matching the scan tool values.  The phone call ended fairly abruptly after faxing over the results.

The guy from Bosch called Peter about 5 weeks later and actually confessed that the system reacted exactly as we mentioned it would once they were able to simulate the cold factor in a freezer tank at their Johannesburg facility. These ECU's can be identified by the part #RSU 906 258 or RSU 906 258A.  Here is a breakdown on them, just in case you happen to still have one of these (there are still plenty out there): 

They were originally set up Open Loop and were not originally calibrated with an 02 sensor.
They were set up and designed by Bosch in SA using 96 Reef octane which Bosch translates into 91 to 93 octane here in North America
The system was simply  not designed parameters wise to be able to pull knock back far enough to a safe range when using 87 octane especially  at RPM ranges of 2500 or more.  The Tiico in-line engines are interference in design.  They are 10 to 1 compression ratio and have extremely high cylinder head pressures.  We've built several long-blocks over the years for PeterB., because of this issue.  Burnt pistons on these engines are almost always because of 87 octane being used for long periods and or a combination of this and incorrect ignition timing.  We know there are those out there who are extremely lucky using 87 octane regularly and have not had a problem.  Here is the reason:  Either their timing or adaptation values are off enough(incorrectly set) by accident… to offset and or  compensate for the burn characteristics of the fuel they are using.  Most of those engines can make it anywhere from 70,000 to 100,000 miles…but not much more than that.  One gentleman who posts on this forum regularly has grenaded  2 engines before because of this… but continues to do it even on his current long block which we built for him.  We've made it very clear to him that zero warranty will be expressed.  If you are out there…please stop telling others to do it so long as they are not pulling long steep hills!! Long hills or not…it is not o.k.  The best results and longevity will be achieved by this product by running 91 at all times or if available 92 or 93.
Adding a 3-wire 02 sensor as mentioned will dramatically change the way these run especially in cold temperatures…they are almost not run able w/o the 02 added in temperatures of 25 degrees Fahrenheit or less.
Even though the ECU recognizes the signal and does make a difference in drivability and engine performance… the parameters are not even close to correct…  and that is why the systems tend to be leaner than they should be under certain loads and RPM and Too Rich fuel mixture wise under others… and it is not always linear or constant.
This system was designed to re-use the Water Boxer injector Bosch part# 0 280 150 206 only.
This system is capable of clearing  DTC's but most will return within a day or two.  Although the system obviously recognizes the 02 sensor signal… due to incorrect parameters in the file formatting they will continue to throw fault codes showing incorrect 02 sensor signal or no 02 sensor signal and adaptation limits either exceeded or not met.
This system is not capable of learning on its own over time and cannot automatically adjust its' fuel mapping parameters at altitudes above sea level.   
Ignition timing on these systems are to be set @ 10 degrees BTDC using  proper basic setting procedure (it requires the use of a digital timing light and proper scan tool**)
Adaptation settings historically @ sea level has shown to be pretty reliable and constant between: 00128 and 00131
Adaptation for altitudes near 1500 ft and above can range between 00139 and near 00165 @ about 6000…**problem with this as mentioned previously… every time you go back and forth between seal level changes the adaptation and ignition timing need to be re-set.  
We have had decent success flashing and upgrading these ECU's to the most current calibrations but not all of them are flashable and you do not know until inside the ecu.
If you have one of these systems and it stores the fault code or DTC:  "Oxygen sensor control limit exceeded " and cannot be cleared due to a hard fault are basically fried or technically locked out from the oxygen sensor portion of the file formatting.   Those who have run across this on their own know that The only solution is to upgrade to the newest  4-wire 02 sensor system .
Second Generation ECU's part #RSU 906 258B or C:

They are a primitive "closed loop" system using a 4-wire 02 sensor with the data wire going to pin #38
They were designed using the water boxer injector and a mild performance cam of 268 instead of a 264** Bosch never discussed this with Remtec or Peter B. ahead of time  and as a result it took us here  almost a year to figure out what was going on with this system and its peculiar glitches.  The mild cam was not that big of a deal except at idle until the engines broke in… but the water boxer injector was!  PeterB. asked them to use the A2 injector #037 906 031AK that fits Digifant Golf's and Jetta's in North America.  They are more reasonably priced and have flow characteristics more consistent with the cylinder volume of an in-line engine.  For whatever reason they didn't.  They also forgot to check all the appropriate boxes while formatting to shut off erroneous codes such as "glow plug monitoring" etc., and as a result they throw more codes than the earlier systems!!
These ECU's learn on their own and do not need to be adjusted at altitude
Ignition timing on these is to be set @ 6 degrees BTDC using the proper basic setting procedure.
In summary if you have ECU #RSU 906 258 B or C make sure you are using waterboxer injectors…your system will run much better.  And make sure the timing is set @ 6 BTDC.  If you have this system and have already upgraded to the A2 fuel rail set-up…you'll need to update your ECU as well.
Current Third Generation ECU's  part #RSU 906 258D:

it took them forever… but, third time is a charm!
I was so frustrated with the 258 B and C ECU's that I personally went over to Bosch SA to get it sorted on our own dime.
A head of time…We sent Bosch the 037 906 031AK injectors and pressure regulator along with the  2.1L Cat and 1.9L rear muffler and current 4-wire 02 sensor.  We also made sure they were using the correct map senor that had parameters to operate below 15 degrees Fahrenheit and verified personally that they actually used all the correct components we sent them when they did their calibration.
The result is a closed loop fully calibrated ECU.  They do not throw erroneous 02 codes or any others that are not warranted.
The ECU's self learn @ altitude and wipe the pants off of the earlier systems in regards to being more emissions friendly.
Ignition timing is to be set @ 6 BTDC using proper Basic setting procedures.  I'm sure the forum's archives list proper timing procedures…but if anyone is confused about it…do not hesitate to contact us.
They are to be run on a minimum of 91 octane.
Sadly, only one production run of conversions was completed before Peter B. went out of business.

We kept our contact with Bosch SA and as a result we were able to bring in 40 new ECU's in '09.  We also brought in about 100 new e-proms to start an exchange program to flash, sort and upgrade those with previous issues.  Unfortunately, not all the ECU's react properly to the e-prom flash…mostly the RSU 906 258A's.

In summary, too little too late for the Tiico conversion in regards to ECU issues that should have never occurred in the first place if Peter B., Remtec and Bosch were on the same page.  We can get more specific in regards to particulates per million documentation emissions wise on the new system and what Bosch shows for specific values on knock regulation parameters in regards to octane if anyone would feel more comfortable with that assurance.  

Hopefully, this will help owners sort out any long standing issues they've been struggling with on their conversions.  We appreciate everyone's support.  We will continue to import any and all of the hard to find conversion items to keep a steady flow for everyone out there.  

Please, do not hesitate with any questions or clarifications!  Back to work…

Best Regards,
Jon Gagnon President of FAS

Moderator edit: FAS's section of this post was structurally modified just a bit for easier reading.

Californio Thu May 02, 2013 12:23 pm

Excellent post. That pretty much tells the story.

Without knowing this or paying enough attention to it, I've been through hell and high water trying to resolve my running issues. There is no way either an amateur like me or a professional mechanic is EVER going to figure out these problems without this information, partly because the O2 sensor readings indicate a fully-functioning closed-loop system. In fact, it is barely functioning at all, esp. with an "A" ECU like I have.

Homercules Thu May 02, 2013 1:18 pm

I've upgraded to the new ECU, FAS exhaust and O2 sensor and at first it didn't run any better. I tinkered with it, cleaned and resealed the map sensor, replaced a few older parts and it now runs like a champ. Starts easier, idles smoothly and can pull steeper grades. I'm still calculating the mileage but I'm sure it will be better than the previous 21mpg. :D

Far_West Mon May 06, 2013 10:44 am

Looking to rebiuld my tiico conversion, any rebuld kits or parts list floating around?

robertgriner Sat Aug 10, 2013 11:12 am

Way more information than my mind can wrap around with details (I've owned my Westy 2 weeks).

I'm chiming in b/c I found this Bosch RSU 906 258A (made in South Africa) device laying under my bench seat (88 Westy w/Tiico). I had no idea what it was (it was laying loose and unattached to anything except a wiring harness with huge connector). I was simply coming online to ask what it was.

I'm gathering that is the computer brain for the Tiico engine? And, it appears that it's an older version that's not doing the best job for my engine? Am I correct? If so, then what steps can I take to replace this unit?

Also -- my engine does tend to have a bit of trouble turning over to get started. Almost like the battery is low, but it's only 2 years old, so I don't "think" it's the battery.

Thanks from the Newbie!

tiicosyncro Sat Aug 10, 2013 3:12 pm

call jon,

Paulbeard Tue Jul 21, 2015 12:28 pm

Bumping this. I found it while looking for info on my lumpy/bouncy idle and occasional stall when rolling to a stop. Mine is an older conversion, early Oughts, so might have the older smarts installed.

rcook52459 Tue Jul 21, 2015 1:24 pm

have you join the tiico yahoo group.will get great info there.

Paulbeard Tue Jul 21, 2015 1:30 pm

rcook52459 wrote: have you join the tiico yahoo group.will get great info there.

Just got my membership card in the mail…

Paulbeard Tue Jul 21, 2015 2:06 pm

robertgriner wrote: Way more information than my mind can wrap around with details (I've owned my Westy 2 weeks).

I'm chiming in b/c I found this Bosch RSU 906 258A (made in South Africa) device laying under my bench seat (88 Westy w/Tiico). I had no idea what it was (it was laying loose and unattached to anything except a wiring harness with huge connector). I was simply coming online to ask what it was.

If the part numbering is logical, you have the first release (the A) and they are now up to the fifth (or E), as noted above.

Quote: FASTT is proud to announce a fresh production run of the 2LR / Tiico 4 cylinder in-line conversion ECU's. Researched, developed, and produced by Bosch, South Africa in full collaboration with FASTT / FAS Inc. The RSU 906 258E designation ECU is the latest issued software package for the very successful in-line conversion program.

I would assume you have an intermediate (B, C, or D, if they exist) installed in place of that one.

No idea what I have or where to look but at least I have a picture now.

Paulbeard Wed Jul 22, 2015 12:06 pm

So I found my ECU, it's a Rev A. What do I get if I replace it with the latest and greatest?

rcook52459 Wed Jul 22, 2015 12:55 pm

Tiico engines run very lean which can burn pistons.adding new computer with a vw A2 fuel rail will help run smoother some say better fuel mileage.just last longer.will also have to upgrade to 4 wire O2 sensor.which none of this is hard to do.

Paulbeard Thu Jul 23, 2015 10:48 am

I just checked in with my mechanic who has done about 30 or so of these conversions. The new ECU was news to him (apparently FAS doesn't update the installers very well) so he is going to look into it and let me know if he thinks it's worth bothering with. $400 is not a trivial expense.

EDIT: He got back pretty quickly and apparently this is not something I can do without replacing the injectors as well. If yours look like this, you're also out of luck.

powellsd Tue Jul 19, 2016 5:26 pm

Why can't one run a higher octane gas to compensate for this? I can find 93 where i live and well i have to use that for my daily anyway.

I can't seem to justify to spend 400 for a new ECU another, 400 for the A2 fuel rail, 150 for the O2 sensor and modifying existing wireharness for the new O2 sensor or even spending more money on a new wire harness.

Zeitgeist 13 Tue Jul 19, 2016 5:57 pm

Just run Digifant II from a late model MkII Golf/Jetta

powellsd Wed Jul 20, 2016 12:07 pm

Zeitgeist 13 wrote: Just run Digifant II from a late model MkII Golf/Jetta

I have located a complete fuel rail setup from 2 different Jetta's and Golf's. Waiting to buy one of them and will be calling FAS about the ECU. So i will be in this for 5-600 bucks.

pdm777 Fri Jul 22, 2016 12:08 pm

I gotta believe that there is a way to adjust mixture without changing ECU and injectors.

BTW; my Tiico (ECU code A) runs GREAT. Easy start, rock solid idle, etc.


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