Which Link Ecu I need for my '93 Mr2 3SGTE Rev2?

[mr293turbo]

Hello,

need your help. I have 1993 MR2 REV2 Turbo USDM. Car was driving well, but after sitting in garage for 3 months it stops firing. Problem is that there is no ECU light on the dash and car not starting, just cranking. For now checked almost everything related to no ECU (even all capacitors are resoldered). Only one thing left is OEM ECU it self. My ECU part number is: 89661-17390 (which is late REV2 I think, after reading some previous discussions).

There is no chance to find another OEM ECU somewhere near me, so I think only one thing I can do is to upgrade my car with Link ECU. As far as I know my engine is in stock condition, no modifications were made.  Only turbo was replaced with CTX28 Garrett GTX2867 gen2 set. I was happy with OEM ECU but think it is not smart to search for another +30 years old OEM ECU.

My questions are:

1. Which Link ECU I need to choose? MR2Link V3 - TST205X or MR2Link V1 - TST185X? I think I need TST205X.

2. Can I just install Link in place of my OEM ECU with no sensors upgrade, just using ST205 map? 
Or I need to purchase together with Link a wide band O2 and new MAP sensors? Any other sensors? If yes, which ones is better? 

3. Is it complicated to program Link by myself? Never did this before and think there is nobody around me who can do this professionally. I don't need everything what Link ECU can give to me, just want my car is back to life and probably engine feels better as now I have modern ECU. My car has only 69000miles and it has historical car plates. It is not for racing, it is for Sunday drive, some photo sessions, some car shows. 

4. Do you know any Link dealers in continental Europe? Please suggest if any available.

[David Ferguson]

I would hate to do an ECU swap on a non-running car.  The original issue may not be addressed, and you will have a very frustrating time getting it up an running.

Can you swap an ECU from a running car to verify the issue is just the ECU?    When cars crank, but don't start, you start with checking for spark / fuel.   Does it have fuel pressure?  Do the spark plugs look fouled?   Do the injectors open when cranking?

Do the spark plugs fire when cranked.   If you have spark, then what happens if you spray some starting fluid into the intake?  

Is the battery good?  Some ECUs won't try running if the voltage is too low, so you need a good well charged battery.   It doesn't take too many cranking attempts to consume the battery, and you will need an external charge before trying again.

If the ECU doesn't seem to think the engine is turning (ie, no fuel pressure, no spark), then I would borrow an oscilloscope to determine if the crank sensor is working.

I think your first step should be to get the car to a specialist mechanic that knows these cars, and do the tests above, and either fix the problem, or identify what the problem is.    Then you can decide if upgrading to a Link ECU is the right step (it may be, and it's certainly more fun to be able to tweak and tune your own car).

 

[mr293turbo]

Hi David,

thanks for your message. Main reason is that my OEM ECU is showing zero life signs. There is no "Check Engine Light" on the dash any more (and this is not a burned dash bulb). This means only few things, no power to ECU or dead ECU. You can check and replace 99% of car parts to new parts, bring it to 10 different specialists, but without working ECU everything will be done for nothing. I will be happy to find anyone with same OEM ECU to check it on my car, but seems nobody in my country who has same ECU in his car. We have facebook group of MR2 cars for our country and I am already asked guys. All they offered to me is ECU from 91 year MR2 rev1, which I think is not good for me to check.

I have done next things to find a problem:
1. Replaced sparking plugs
2. Replaced distributor cap and rotor
3. Checked spark on a main wire to distributor and on each spark plug. There is spark and it is good in my opinion.
4. Checked battery and fuel. Battery is systematically charged by ctek charger.
5. Have disconnected one by one and all together next sensors: Air flow meter (didn’t touch the screws), turbo pressure and throttle position sensors. I have read they can cause ECU to shut down.
6. Jumped a paperclip on fuel pump contacts Fp and B+. Pump is working perfectly
7. Jumped a paperclip on TE1 and E1 to read codes, but when there is generally no CEL light, there was no success to read anything
8. Got a voltmeter and checked voltage supply to ECU (+B and +B1 to E1 and ground) it shows 12.5V
9. Checked ECU contacts BATT – E1 it shows same 12.5V
10. Checked all related fuses, all are ok
11. Moved ECU off, opened it and found 3 capacitors where leaked. Decided to replace all 8 capacitors with low impedance Panasonic capacitors. A professional guy made a soldering job for me. No joy.

What else I need to check? BGB indicates that in my case I need to try another ECU. This can be problematic in my location to find anyone with same ECU. Is it any more tests I can perform to make sure that ECU is good or not? I think there is no needs to crank the engine anymore until I'll see the CEL light is returned to the dash when key is at ON position. When I know if that was a faulty ECU, I think it is better to go to some aftermarket options as Link or other brand instead searching for another 30 years old OEM ECU.

[Adamw]

I initially had similar thoughts to David but I will add some of my own comments to ponder about the finding the actual root problem:

• You say it has spark when cranking, so that really only leaves 3 possibilities for a no start - the spark is at the wrong time, there is no fuel, or there is no air/compression.  
• Spark timing can be confirmed with a timing light, or even a just a very basic eyeball verifcation to make sure the rotor is pointing to the correct post in the distributor when the engine is sitting at TDC would confirm it is close enough to run.
• All fuel related problems can be quickly ruled out by a squirt of starter fluid into the intake when cranking - if it gives a cough or tries to run on starter fluid then you can concentrate more on why there is no fuel reaching the combustion chamber via the normal injectors.  A cheap LED test light can be used to verify injector pulses, and you can do tricks such as spinning the distributor by hand to test without the engine running. 
• If there is still no signs of life with starter fluid added then you can scratch all fuel-related possibilities off the list.
• When fuel and spark issues have been ruled out then I would concentrate more on investigating compression, a compression test doesnt always tell the full story but it is still a valid first test to try, I have found compression testing doesnt always pickup cam timing issues so I would also manually verify cam timing, there could be a stripped cam belt or it has jumped some teeth etc.  

 

Some answers to your original questions:

1. Yes, the TS205X ecu is the one that matches the 17390 pinout. 
2. You would need to at least add an air temp sensor.  It doesn't necessarily need to be a Link sensor, any common air temp sensor will do, and it can usually be wired to the original airbox temp sensor wires.  The factory MAP sensor is ok up to about 25psi boost from memory.  A wideband would be needed if you intend to tune it yourself.
3. Initial setup and getting it to run is relatively straightforward if you have an interest in it.  However, this will only get it running and maybe drivable, it certainly wont drive well or make any power and wont be safe to drive hard.  There is a lot to learn from the tuning side and it would be quite a daunting task trying to learn how to tune and making all the normal mistakes on a 30year old turbo engine that wasn't particularly strong when new.  There are some training organisations such as HP Academy or Evans Performance that would probably be a wise investment to learn at least the fundamentals before you jump in.  But unless you had a real strong desire to learn and do it yourself, I would suggest trying to find an experienced tuner, if you dont have any locally then there are some that would offer remote tuning, although I've never been particularly fond of that option.  
4. There is a dealer list here that you can try:  https://linkecu.com/dealers/dealer-network/   

[mr293turbo]

1 hour ago, Adamw said:

I initially had similar thoughts to David but I will add some of my own comments to ponder about the finding the actual root problem:

• You say it has spark when cranking, so that really only leaves 3 possibilities for a no start - the spark is at the wrong time, there is no fuel, or there is no air/compression.  
• Spark timing can be confirmed with a timing light, or even a just a very basic eyeball verifcation to make sure the rotor is pointing to the correct post in the distributor when the engine is sitting at TDC would confirm it is close enough to run.
• All fuel related problems can be quickly ruled out by a squirt of starter fluid into the intake when cranking - if it gives a cough or tries to run on starter fluid then you can concentrate more on why there is no fuel reaching the combustion chamber via the normal injectors.  A cheap LED test light can be used to verify injector pulses, and you can do tricks such as spinning the distributor by hand to test without the engine running. 
• If there is still no signs of life with starter fluid added then you can scratch all fuel-related possibilities off the list.
• When fuel and spark issues have been ruled out then I would concentrate more on investigating compression, a compression test doesnt always tell the full story but it is still a valid first test to try, I have found compression testing doesnt always pickup cam timing issues so I would also manually verify cam timing, there could be a stripped cam belt or it has jumped some teeth etc.  

 

Some answers to your original questions:

1. Yes, the TS205X ecu is the one that matches the 17390 pinout. 
2. You would need to at least add an air temp sensor.  It doesn't necessarily need to be a Link sensor, any common air temp sensor will do, and it can usually be wired to the original airbox temp sensor wires.  The factory MAP sensor is ok up to about 25psi boost from memory.  A wideband would be needed if you intend to tune it yourself.
3. Initial setup and getting it to run is relatively straightforward if you have an interest in it.  However, this will only get it running and maybe drivable, it certainly wont drive well or make any power and wont be safe to drive hard.  There is a lot to learn from the tuning side and it would be quite a daunting task trying to learn how to tune and making all the normal mistakes on a 30year old turbo engine that wasn't particularly strong when new.  There are some training organisations such as HP Academy or Evans Performance that would probably be a wise investment to learn at least the fundamentals before you jump in.  But unless you had a real strong desire to learn and do it yourself, I would suggest trying to find an experienced tuner, if you dont have any locally then there are some that would offer remote tuning, although I've never been particularly fond of that option.  
4. There is a dealer list here that you can try:  https://linkecu.com/dealers/dealer-network/   

Hi Adam, I'm also not a fan of replacing the ECU on a dead engine. What you wrote about finding the problem certainly makes sense. But should I start looking for a timing or compression problem when I see that my ECU is not working and it seems like it is 99% the cause of my problem?

When I turn the key to the ON position, the Check Engine light on the dashboard does not come on and there is no sound from the fuel pump. The fuel pump has been checked and is working and receiving power, but there seems to be no signal from the ECU. I'm confident the compression is good as the car has a full service history and was running more than perfect before I left it in my garage. The timing belt was changed only 6000 miles ago. Even if I found that there is no engine in the engine bay at all, this does not answer the question of why the ECU is not working. This is why I think I need to start solving this problem starting with the ECU since it is an obvious problem rather than starting with the mechanical parts of the engine. In any case, replacing ECUs is cheaper than replacing engines and finally return to ECU swap. 

I have a complete repair manual for the MR2 and have run the ECU tests according to the manual. In my situation, BGB suggests trying a different ECU. Since there is no other control unit, I start looking for options. Options: Buy an OEM ECU +30 year somewhere on Ebay, pay $500, $800 or more for it and get the same thing I have in my hands. It's a lottery. It can takes forever to find same p/n ECU at Ebay or somewhere else.
Another option is to save that $500, $800, or more and upgrade to a more expensive standalone device with a guarantee that it will work.

I know the best solution is to go to my neighbor who has the same car, take his ECU, put it in my car and try. But there is no neighbor with the same car.
Of course, if I take a Link ECU and this also does not solve the problem, I will look deeper for a solution, but this will already be with a modern ECU.

[Adamw]

9 hours ago, mr293turbo said:

But should I start looking for a timing or compression problem when I see that my ECU is not working and it seems like it is 99% the cause of my problem?

All Im saying is I wouldnt jump to the conclusion that the ECU is dead just because the CE light and fuel pump isn't working.  The fact you have spark when cranking suggests at least the majority of the ecu is working.  It certainly could have some dead outputs (which renders it useless), but I think there is still a good chance it could just be a combination of a couple of smaller issues such as a corroded ground connection and stuck injectors causing the appearance of a dead ecu.  So Im just suggesting to try to rule out as many of these fundamental possibilities as you can, a lot of it can be ruled out with only a time commitment, and no real monetary cost.

And while I agree with your logic that it makes more sense to replace the ecu with a new aftermarket "guaranteed working" ecu - assuming the cost was going to be similar to a risky a second-hand unit, but I think you may be underestimating the total cost of installation.  If you consider the ecu cost, setup and calibration time, paying someone to tune it or buying courses and tuning equipment to learn to tune yourself, then hundreds of hours of learning, many tanks full of fuel etc, the cost difference will be much larger than you think.  Depending how much you ended up doing yourself, my guess would be the total cost of an aftermarket ecu install would usually workout 2-3 times the cost of the aftermarket ecu.     

Having said that, a good aftermarket ecu with good support can certainly make diagnosis easier - you can view live data, record data, there are functions like trigger scope, ignition and injector tests built-in etc, so this may be a consideration also.

 

 

 

 

[mr293turbo]

On 6/6/2024 at 2:12 AM, Adamw said:

All Im saying is I wouldnt jump to the conclusion that the ECU is dead just because the CE light and fuel pump isn't working.  The fact you have spark when cranking suggests at least the majority of the ecu is working.  It certainly could have some dead outputs (which renders it useless), but I think there is still a good chance it could just be a combination of a couple of smaller issues such as a corroded ground connection and stuck injectors causing the appearance of a dead ecu.  So Im just suggesting to try to rule out as many of these fundamental possibilities as you can, a lot of it can be ruled out with only a time commitment, and no real monetary cost.

And while I agree with your logic that it makes more sense to replace the ecu with a new aftermarket "guaranteed working" ecu - assuming the cost was going to be similar to a risky a second-hand unit, but I think you may be underestimating the total cost of installation.  If you consider the ecu cost, setup and calibration time, paying someone to tune it or buying courses and tuning equipment to learn to tune yourself, then hundreds of hours of learning, many tanks full of fuel etc, the cost difference will be much larger than you think.  Depending how much you ended up doing yourself, my guess would be the total cost of an aftermarket ecu install would usually workout 2-3 times the cost of the aftermarket ecu.     

Having said that, a good aftermarket ecu with good support can certainly make diagnosis easier - you can view live data, record data, there are functions like trigger scope, ignition and injector tests built-in etc, so this may be a consideration also.

 

 

 

 

Hi guys. I think it’s time for me to add new information to this topic, which may be useful to other people who find themselves in my situation. And it seems that there will be more and more such people over time. It took me 3 months to find the problem and yesterday it was resolved. It was the ECU. I already mentioned that all the capacitors were replaced, and visually everything looked great on the boards. In one of the MP2 groups on Facebook I read a post about a similar problem and there the guy was advised to contact an ECU specialist named John Mears (he is well known as a person who can solve ECU problems). I contacted John and sent my ECU to him in the UK. John fixed my ECU. The problem was in one track on the board, which was visually in order, but in fact was spoiled by electrolyte from the previous capacitor. The track was rebuilt and the ECU now works great. The car starts perfectly.
I won this battle and now I have time to read and study the topic of autonomous ECUs. Read a lot of information about Link and Megasquirt. It seemed to me that Megasquirt is a little easier to configure and perhaps I can tune it myself. But Link looks a class above and requires the approach of a professional tuner. What do you think?

[Confused]

Absolutely the Link can be tuned yourself too, but for best results from all, you want an experienced tuner who understands the software and the process. We're biased, but the Link is a few steps above Megasquirt in terms of functionality.

[Laminar]

I've run a Megasquirt on one of my cars for the last 9 years and I'm putting a Link on my next car. Link has significantly more flexibility and configurability. I'd say easy of configurability is a wash. It took me a second to get into the Link mindset but it makes sense as long as you figure out a couple of quirks. Megasquirt is fairly fixed, you probably need to make sure it explicitly supports your trigger wheel setup. Link is a bit more universal in that way with configurable cam pulse settings, software-configurable pullups, high frequency inputs, and flexible trigger input hardware.

Megasquirt has the advantage for dash configuration - the PC software has a lot more configurability for gauges and displays, and you can export those displays directly to a $10 Android app. Link would have you buy a $1300 dash or use a 3rd party app. Megasquirt's log-viewing software MegaLogViewer is powerful and popular with even non-Megasquirt ECU logs as it displays CSV files in a really nice way.

I'm pessimistic about Megasquirt's development, the support seems to have fallen off, it's hard to get anything from the developers. Forum support here is top-tier, Adam and Vaughan absolutely kill it day to day.

[koracing]

*IN MY OPINION* reasons to choose link over megsquirt:

#1 - lifetime warranty

#2: fuel pressure compensation (when equipped and set up for a fuel pressure sensor) - megasquirt can't do this - I've tried

#3: Worldwide support from the company and a professional dealer network.  You get support from people who have tuned hundreds and thousands of ecus, instead of support from hundreds and thousands of users who have tuned one car each.

I'll skip reasons 4 through 38 and just say I've tuned both ecus - professionally - on mr2 turbos.  The first and last megasquirt I sold and installed on a MR2 Turbo had to be replaced 4 times due to hardware failures. 3 of them within weeks of each other due to poor product validation/lack of any quality control or testing). 

Does megasquirt work?  Sure.  So do carburetors and the Apex'i Power FC, but it's not 1998 any more.

BTW, I do use megalog viewer for viewing and manipulating logs from various other ecus.

[steere]

Just a thought about your original ecu have you bridged the TE1 and E1 terminals in the diagnostic plug the check light should flash or stay on at least.

[mr293turbo]

7 hours ago, steere said:

Just a thought about your original ecu have you bridged the TE1 and E1 terminals in the diagnostic plug the check light should flash or stay on at least.

Yes, tried everything. The problem was in one of ECU board tracks which was damaged by leaked capacitor. Now ECU is fixed and I am reading and learning things about standalone ECUs.