Stand-alone ECU choices

[acox99 71 1 Cars]

I’ve been debating for sometime whether to change over from jetronic to a modern aftermarket standalone system for some time. The car is a 1.6 gti, it’s not standard but I like the more period tuning techniques & for something to look original so an engine change isn’t on the cards. The Tolman 1.6 has got me thinking about modern management, but out of all the options of Omex, Emerald what is the best & easiest route. The only criteria I have is I will keep the AFM, gutted or modified to work, I will keep the SAD rather than a proper idle valve & I will keep a dizzy, but changing it for a mk2/3 golf unit so that it only either distributes the spark or acts as a cam sensor. I don’t want to go down coil pack route, superior or not as I want it to at a glance look original, I’m looking for drive ability more than power, but it would give me the option of a slightly more aggressive cam. With this in mind would Emerald be the best option? 

[petert 550]

Find someone to map it first and keep it local. For example, the brands Omex and Emerald don't exist in Aus. It's either Motec, Emtron or Haltech now.

 

Triggering from a crank angle sensor, in addition to a 16V flywheel is the easiest way forward. Do you have many Motronic 8V flywheels in the UK? Triggering from the dizzy is a pita, otherwise you need to adjust the rotor phasing.

 

Gut the AFM and use the oem air temp sensor. Part of your research is asking whether your new ecu can read the oem sensor.

 

 

[welshpug 1,622]

Flywheel should be easy enough to find 1.8 16v used them, or fit an xu10 flywheel and use the 1.9 mi16 clutch.

 

Dizzy wise you can lock the advance off or use the motronic dizzy..

[SRDT 146]

If you just want to use the VW distributor as a cylinder reference sensor for sequential injection you could also look at the pulse sensors that fit on ignition leads. BMW used them but also Peugeot/Volvo on their B280 / ZN3J 2.8 V6.

[Tom Fenton 1,525]

How about use the Motronic “dizzy” to as you say distribute the spark, with the Motronic crank sensor and flywheel?

OK the cap is black rather than orange, but at a glance it’s still a distributor of sorts and in the right place on the end of the cam.

I have used Emerald a lot and found it good to use, good support when needed as well. But as said above, find someone localish to you that you trust to map it, and see what they like to use.

[Anthony 1,000]

On 9/30/2023 at 8:56 AM, acox99 said:

I will keep the SAD rather than a proper idle valve 

 

If you're planning to do this, consider carefully how you're planning on measuring engine load - I retained the SAD on a 1.9 8v that I converted to Emerald for a friend, and using TPS-based load (known as Alpha-N tuning) it didn't really work very well and in the end we removed the SAD completely post-mapping.  In hindsight, we should have predicted this as the ECU has no way of "seeing" the additional airflow from the SAD and probably would likely have worked much better either using a MAP sensor for load or using an idle control valve that the ECU could add additional fuel to compensate.

 

With the SAD removed completely and just relying on Emerald's ignition advance idle control alone, cold starting was reasonable but would sometimes need to be helped with a touch of throttle for a moment or two after initial start - ironically not too dissimilar to the Jetronic setup that we'd just junked.  Once started, it would keep idling pretty well even in cold weather, and hot idle was good  

 

I've no personal experience with Omex, but have owned/used both DTA (E48/S40) and Emerald (M3D/K3) and found them both to be good.  As others have said, best speak to whoever you'd planning to use to map the car and discuss with them.

[SRDT 146]

Peugeot kept the SAD on the XU9JAK D6E and XU9J2 D6D engines with MP3.1 injection so yes it can be done.

[acox99 71 1 Cars]

Thanks for the advice, I did think if junking the sad and just using the idle screw as per what a throttle body setup would do, it’s not cold start that bothers me with jetronic, it’s the stalling at junctions & generally going out of tune as soon as you’ve done 10 miles again. I’ve replaced the majority of components. Had the dizzy rebuilt, cleaned & replaced the AFM but feel it’s time to start looking at other options. The components aren’t going to last forever as they are resistors, diodes, bi metal strips & springs which all have a life span. 
 

i would happy use motronic parts but they are rare in themselves hence the golf dizzy idea & it’s a slightly more modern setup. I would use a GTI6 TPS or similar, or hide a map sensor somewhere, I just want it to look original at a glance hence the AFM all be it stripped out, Dizzy & coil. 

[petert 550]

There’s plenty of Motronic dizzys in Aus. I’d just lock the original up though. Modern ecu’s have internal map sensors.

 

I don’t get it. You want it to look original but you’re happy to graft on a GTi6 TB or use a VW dizzy?

Edited October 4, 2023 by petert

[acox99 71 1 Cars]

Not gti6 throttle body, fit a modern TPS onto the original throttle body. 

[petert 550]

Easy job if you make an adaptor plate to pick up the oem mounting holes. You’ll just need to work out if you need clockwise or anti-clockwise.

[SRDT 146]

Isn't there a TPS that simply fit? 1920.0F was used on the XU9JAK D6E and 1628.L1 on the XU9J2 D6D.

[Anthony 1,000]

40 minutes ago, SRDT said:

Isn't there a TPS that simply fit? 1920.0F was used on the XU9JAK D6E and 1628.L1 on the XU9J2 D6D.

It will bolt up to the casting, but certainly the XU9JAK (1.9 ZX Volcane) type will need the spindle machining as it using a flat I-section rather than the D-section end that the Jetronic throttle switch (and GTi-6 TPS) does.

[Richie-Van-GTi 70 2 Cars]

I run a reasonably stock 1.6 engine with an adaptronic ECU, i use a wasted spark coil from a 406 turbo, dual channel amplifier and idle valve from an MI16 and a map sensor in the ECU. Flywheel is a billet job from TTV with a 215mm push type mi16 clutch. Dizzy, afm and sad all gone. Its only 120bhp but its got that modern reliability to it.