One of my locals is building up a 185 as a toy and part of this build is an aftermarket ECU. He had bought a Link G4 plug & play for MR2 / celica 185 but had no experience with ECU's so I gave him a hand fitting it & getting it running. Since no-one has yet posted up experiences of this ECU I thought i would share.

My first surprise is that it was just a PCB assembly with no enclosure. It looks like they've made a standardised ECU board which then plugs into a motherboard which is customised to the model of car so it fits the standard ECU enclosure and carries the same connectors.









There is a short flying lead with a connector to link to USB via a further supplied cable. We decided to put a notch in the case to bring this out, also leaving some spare space for extra inputs & outputs from the expansion connectors available on the motherboard.



It was a pretty straightforward job pulling the innards out of the old ECU case and screwing the new one in and it then fitted & plugged in exactly as a standard ECU would, with easy access to the USB port.

The ECU comes with a base setup designed to run the car straight away, and to be fair it fired straight up and was drivable up on to a ramp. From the box, it uses the 'turbo pressure sensor' on the 185 as a MAP sensor allowing the AFM to be ditched. It does, however, use the intake air temperature sensor built into the AFM so ideally would need a separate intake air sensor fitted, preferably in to the post-chargecooling pipework.

The ignition timing was checked and was spot on, so it seems the default timing corrections are correct for the car.

The throttle position sensor was a little out, reading 3.5% at zero throttle, preventing the idle control cutting in correctly. Setting the sensor calibration was a quick job using the PC software - which needs to be downloaded from the website.

I haven't looked at the default ignition map yet, but the car ran smoothly with no signs of det. It's certainly good enough to get to a rolling road.

The defaullt fuel map was very rich at the low end and idle, so i dropped the master injection control a little and then found it was somewhat lean on boost. We took the car on a run up the dual carriageway and I got the mixture reasonably close on the cruising cells and nicely over-rich on boost for safety. He will be fitting bigger injectors in the next few days so i'll re-visit the fuelling and get it a bit closer then.

The other setting I changed was the ignition dwell time - it was set to 4mS at 14V as default. This was the factory default on my G3 and caused overheating of coil / ignitor on both my 185 and 205 leading to an intermittant misfire. This is what I'm suspecting casued my repeated ringland failures. I dropped it down to 3mS - the same as I'm now running on the 205.

All in all, about 4 hours to fit the ECU, wire in an AFR gauge to the ECU power, get it running and do a very quick 'safe to drive about' setup & map.

There is a setting in the ECU menu for 'knock control' which is currently turned off. I didn't see any listing of 'knock sensor' on the analogue inputs so at this stage I don't know whether it's built in or not. I will update as I do more research and spend some more time with it.

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If at first you don't suck seed, try drier grain.

Interesting read - this ECU was one of my main choices for the ECU on my car.

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GT4DC Events Co-ordinator
1996 ST205 UK

Seems a bit silly to use the stock pressure sensor for fuelling it tops out about 17psi. And that's very easy to exceed with even a stock small ct26 from the st185. If its got a free flowing exhaust, add a better inter warmer and troubles are ahead, I'd say a 3 bar sensor needed as a minimum , not the stock 2.5 bar one on the st185

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Darryl

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Darryl

We fit these
To ditch the afm you need to splice the 2 wires out the loom, we then fit a bosch air tem sensor in the 5th injector hole under the throttle body, we make a alloy plate to mount them. We also ditch the standard lamda as if you fit a wide band the ecu will do self fueling. They do come with a 3bar map sensor on the ecu but we change them for a 7bar. The ecu will run the dizzy or you can change to wasted spark or coilon plugs, we tend to run wasted spark.
To use the knock control you need a knock link which is a seperate unit.

Hth

Sent from my GT-P5110 using Tapatalk 2

There was no sign of a built in MAP sensor, unlike the G3 I'm familiar with.

You can run a separate MAp sensor fed into a different analogue input according to the handbook. I would personally be inclined to fit a higher pressure one in place of the stock one and live with the dash gauge reading different.

As it is, it does at least mean you get a true 'plug & play' ECU as a starting point. For now, I've set the boost limit just shy of the upper limit of the MAP sensor so it's safe.

What is a good source of 3 or 4 bar MAP sensors ?


I'm a bit dissapointed to find the knock sensing isn't built in - would have been quite easy to include a generic knock amplifier on the ECU or even a car-specific one on the motherboard.

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If at first you don't suck seed, try drier grain.

7bar ? What accuracy is the ADC running ? If only say 10bit that seems daft loosing resolution on pressures that few 3s-GTE engines will ever reach. 3 or maybe 4 bar would be fine for most, certainly no more than 5 bar needed surely ?

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Darryl

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Darryl

Out of interest, what pressure does the 205 MAP sensor go up to ?

Bearing in mind the PFC runs from these, and I've heard of people running 1.5bar boost or more with these.

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If at first you don't suck seed, try drier grain.

We run 1.4 to 2.2bar on our cars adjustable from dash via a pot switch. A 205 standard sensor will run 1.5bar

Sent from my GT-P5110 using Tapatalk 2

Thats because you have boight the lesser spec g4 if you buy the g4 extreme its all built in but it wont fit the standard loom without a link block

Buy thegm map sensor its 4bar which works fine with the link or I have some 3 bar link map sensors in stock

Sent from my GT-P5110 using Tapatalk 2

GM sensors come in a variety of pressure ranges - most are the same shape on the outside. Also be cautious as many on eBay are not genuine GM.

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GT4DC Events Co-ordinator
1996 ST205 UK

The 205 runs to 23psi and allowing for vacuum as well its a 2.5 bar range.


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Darryl

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Darryl

Hoping to wire in one of my knock boxes tomorrow & get knock control running. Very little technical information on the site, the only detailed information is in the help file for the PC software.

https://dl.dropboxusercontent.com/u/831 ... 20link.pdf

It seems rather crude in that it retards timing over the entire RPM & load range when knock is detected then gradually puts it back. Since knock mainly occurs at higher loads and mid RPM, this leaves you wanting to put timing back fairly quickly meaning that next time you give it some welly you'll get loads of knock again. It does allow lockout at lighter throttles and lower & higher RPM as a workaround, but this leaves you unprotected in those areas in extreme conditions.

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If at first you don't suck seed, try drier grain.

To say I'm Peed off with link at the moment is an understatement.

The literature says it will take an analogue 0-5V 'knock level' signal or a digital (presumably a datastream from the knocklink). Went to configure it as an analogue after wiring it all in and it would only offer digital. Turns out, the later versions of firmware dropped the facility claiming it never worked properly.

I'll see what they say at Thor on Thursday, assuming they are still link dealers.

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If at first you don't suck seed, try drier grain.

A bit of a non-day at Thor today. We were ushered into a very plush waiting room while they took the car in to the workshop for mapping after a quick chat. We were not allowed to stay with the car for insurance reasons !!!!
On the plus side, I was pleasantly surprised at the map produced in a short time. My laptop went flat before I had a chance to download & look, but the car ran very smoothly and the mixture wasn't a huge way out over most of the range, certainly the sweetest running 'quick map' I have encountered. Also, the full boost AFR was in the high 10's and occasional 11's so they left a reasonable safety margin.

As far as the knock side of things (Thor being the sole UK distributer for link) he was going to make some enquiries and get back to us. His comment was that he has a number of customers running analogue knock systems so they would currently be unable to upgrade firmware. I will chase this as I think the ECU will be a more attractive proposition if there is a cheap knock interface available that can work with it.

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If at first you don't suck seed, try drier grain.

7 bar seems abit excessive, whos going to run 6 bar boost pressure.

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