ECU Delete?

[kenwood720]

Hello,

I am about to be on my 3rd ECU for my 91 TSI Talon. (Lots of clicking, car won't start, won't stay on, randomly dies, etc.) (Also, the Auto trans does not work unless I use 2 switches to control the solenoids, tried 2 different TCU)

The real question is, is it possible to run the engine with some type of completely aftermarket equipment that doesn't involve a DSM ECU?

 

[Bud92gsx]

2g ecu, halltech, evo. You've got more than one option. The ecus you got the caps could have puked all over the board causing a no start. You should send one of them into ecmlink or my1gdsm to be repaired. Then you'd know for sure weather its wiring or bad parts.

Your probably getting bad tcus.

You might have alot of bad wiring to begin with. But im betting your getting bad parts sumhow.

 

[motomattx]

Tcu's can go bad and do go bad alot as they are getting older, the shift solenoids in some cases start to draw too many amps as they get older and it burns up the drivers in the tcu, I have also noticed tcu's going bad from the actual on board power supply components of the tcu itself just failing, its almost impossible to find a good 93-94 auto tcu now so dont feel bad . There are many aftermarket ecu options for the cars these days, the 2g black box is very reliable, the Halthech, the AEM the LinkEcu, etc. some of the aftermarket ecu;s can even be setup to shift your auto which can eliminate your tcu completely.

 

[kenwood720]

Tcu's can go bad and do go bad alot as they are getting older, the shift solenoids in some cases start to draw too many amps as they get older and it burns up the drivers in the tcu, I have also noticed tcu's going bad from the actual on board power supply components of the tcu itself just failing, its almost impossible to find a good 93-94 auto tcu now so dont feel bad . There are many aftermarket ecu options for the cars these days, the 2g black box is very reliable, the Halthech, the AEM the LinkEcu, etc. some of the aftermarket ecu;s can even be setup to shift your auto which can eliminate your tcu completely.

With respect the above mentioned ECU's, which of those options would required the least amount of modifications. If modification need to be made, I am willing to do that. I just need to be pointed in the right direction. I have read about replacing this ECU with a manual version which requires only a few changes but that option was not listed above.

I found Halthech on https://www.haltech.com/product-category/mitsubishi/eclipse-1g-turbo/ While this does seem like an option, the price tag is restrictive for me until I upgrade other areas of the car.

With regards to the 2g black box, I did not find much on it using it in a 1g.

My goal would be to have an ECU that works, but also can be hooked up to a laptop for modifications and error codes. My last setup involved a Palm III with a pocket logger software. That setup did not work well at all.

 

[kenwood720]

You should send one of them into ecmlink or my1gdsm to be repaired. Then you'd know for sure weather its wiring or bad parts.

I always thought that these companies only replaced caps and sent them back without really testing. I have 1 ECU which looks great and was repaired once before. The other ECU is probably destroyed since I can see the PCB board exposed.

 

[motomattx]

You should go with the 2g black box or Evo8 ecu, they will require a patch harness or a rewire on the ecu connectors, but its worth the work.

 

[Bud92gsx]

If ecmlink doesnt test the ecus when they are paid to fix thenecue issues. I doubt they would still be in business . Is still reccomend ecmlink or my1gdsm tuning services, I vouch for stacy personally. He also makes patch harnesses last I knew https://www.facebook.com/My1gdsmTuningServices/
Theres a ton of info out there on tuners about swapping to a 2g black box, weather it be a patch harness or swapping ecu pins etc.
I thought I say on this thread something about the MT ecu in an auto, I'll refresh and edit my post if I see it.

I do love how my toggle switch method is still getting used tho, I appreciate folks getting use out of it.

 

[Bud92gsx]

its almost impossible to find a good 93-94 auto tcu now so dont feel bad .

I beleive there interchangeable, but was it the 89/90 that used a 2 plug tcu, where I know 92/94 are 3 plug tcu.I'd stick with the same model awd fwd that you have. The shift points might not be the same if u pick fwd on an AWD trans. Theres been some debate I know of on this subject.
Edit. I was trying to say 3 and 4 wire off the trans, not 3 and 4 plug tcu.

 

[motomattx]

I beleive there interchangeable, but was it the 89/90 that used a 3 plug tcu, where I know 92/94 are 4 plug tcu.I'd stick with the same model awd fwd that you have. The shift points might not be the same if u pick fwd on an AWD trans. Theres been some debate I know of on this subject.

The shift points are different especially between the 1.8 and the 2.0, the earlier tcu is easier to find in good shape because its built stouter than the newer ones, but the plugs are of course very different, some of the newer tcu's have eprom in them though which can be programmed to shift where you want.

 

[1990TSIAWDTALON]

Early 92's, like mine, have a 3 plug TCU #MD750092. 1 plug is the power and grounds, 1 plug is all of the inputs and the last plug is all of the outputs. Mine is susceptible to the VSS signal not always working, as that signal comes out of the speedometer, putting it into limp mode. A shift box takes care of it, like the OP has switches to operate the solenoids.
I would definitely send the ECU to the guys at ECMLink and let them do their thing, they are good at it.

 

[kenwood720]

Thank you for all the suggestions. The person from Facebook looks like they haven't done anything since 2015. I just sent an email to ECMLink in hopes that they can repair my unit or find me a socketed ECU with ECMLink.

 

[kenwood720]

Early 92's, like mine, have a 3 plug TCU #MD750092. 1 plug is the power and grounds, 1 plug is all of the inputs and the last plug is all of the outputs. Mine is susceptible to the VSS signal not always working, as that signal comes out of the speedometer, putting it into limp mode. A shift box takes care of it, like the OP has switches to operate the solenoids.
I would definitely send the ECU to the guys at ECMLink and let them do their thing, they are good at it.

I found a thread on ECUs which lists the part numbers. https://www.dsmtuners.com/threads/1g-tcu-guide.277172/

MD738998 91-92 FWD, 1.8L
MD750092- 90-92 AWD <------------------This is what I have. Well two of them at this point.
MD750093 91-92 FWD, w/turbo
MD750525 91-92 FWD, 2.0L, w/o turbo
MD754075 93-94 FWD, w/turbo
MD754076 93-94 AWD
MD754077 93 FWD, 1.8L
MD754079 93 FWD, 2.0L, w/o turbo
MD756600 95 FWD, w/turbo
MD756601 95 AWD
MD756916 94 FWD, 1.8L
MD756917 94 FWD, 2.0L, w/o turbo
MD759736 96 FWD, 2.0L, w/turbo
MD759737 96 AWD
MD762042 97-99 FWD, 2.0L, w/turbo
MD762043 97-99 AWD
MR483685 97-99 FWD, 2.0L, w/turbo
MR483686 97-99 AWD
(Thanks to GDNF2ET )

Once I get the ECU fixed, I can go back and try and troubleshoot the TCU. The VSS issue is new to me, so I will look into that.

 

[1990TSIAWDTALON]

I have two more complete gauge packs to try and cure the issue i have. My TCU had new caps but not by me. It worked for about 2 weeks then went into limp mode and wouldn't reset. Only cure for me was a shift box but my shiftbox ALSO relies on the VSS so I need to change speedometers or the whole cluster which is alot easier.
The TCU has an input for the VSS but it isn't the best signal generator out of the speedo.
Hope that helps.
I do have a few 750092s for spares as soon as I get the limp mode to go away on my auto 6/4 car.

 

[steve]

I do have a few 750092s for spares as soon as I get the limp mode to go away on my auto 6/4 car.

Make sure the caps get changed before they blow up the power supply in the TCU once they do that, it frys everything else on the board unlike when the ECU caps go bad.

 

[1990TSIAWDTALON]

Thanks Steve, I will open all of them up. Any particular cap spec that you can recall? I really don't expect you to know, but if anyone would, it would be you. I would like to recap them all.

 

[steve]

The serious troublemaker is the 47uf cap next to the transistor mounted to the heatsink.

 

[1990TSIAWDTALON]

You never disappoint!
Thanks Steve.

 

[Bud92gsx]

So heres the big 47uf cap. Same MD 750092 tcu. Are the black one the caps you said replace?

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[steve]

That's the one that usually leaks and kills the TCU.

 

[kenwood720]

I took the recommendation of sending the ECU to ECUTuning. They tested it and did not find any issues.

I just posted a follow-up question about Fuel PSI and how I am reading higher than norm.

 

[kenwood720]

Followup. I replaced the fuel pump with a walbro 190 (all stock still). It was running fine but after a while started stalling again. As long as I keep it 3000+RPM, it's fine without any check engine lights. It takes while to start.....cranking..... but once it starts it's good. I suppose I should think about replacing the fuel filter after it sat for 8 years.

For the transmission, I feel that I located a bad pulse generator. Pins 1 and 2 report 330ohms but 3 and 4 report and open circuit. Next job will be to find another pulse generator which is already proving difficult to fine.