Is this a good ECU????

[davidalindsey]

I have been trying to figure out why I have a high idle(I am waiting for my boost leak tester to come in the mail), so in the mean time I took out the ECU and from what I can tell it looks to be fine.
I just want some other people's opinion's.

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[1995gsx20g]

in the second pic by the connectors i think i see some damage if you can get a better pic of that side of it i would know alot more. also check out this corrosion2g01 [ECMTuning - wiki]

 

[Ceddy]

Looks fine.

IC12 and IC17 control the ISC I believe. When they burn up its usually pretty obvious.

Try readjusting the ISC to fix high idle and idle surge.
Also check the BISS and for vacuum leaks.

in the second pic by the connectors i think i see some damage if you can get a better pic of that side of it i would know alot more. also check out this corrosion2g01 [ECMTuning - wiki]

The brown stuff is lacquer, not corrosion.

The 98/99 ecus don't have electrolytic capacitors like the 90-97, so don't suffer from the leaking capacitor/corrosion problems.

Better pics would help though.

 

[davidalindsey]

How do you adjust the ISC?
I Just put a new ISC motor in there, I have installed and reinstalled that thing so many times now.
Is there a certain way they have to go in?
I am waiting for my boost leak tester arrive.
--------
I just put the computer back in, thats all the photos I have of the ECU. You can enlarge them.
The ECU is off of a 98 GST.

 

[1995gsx20g]

Looks fine.

IC12 and IC17 control the ISC I believe. When they burn up its usually pretty obvious.

Try readjusting the ISC to fix high idle and idle surge.
Also check the BISS and for vacuum leaks.



The brown stuff is lacquer, not corrosion.

The 98/99 ecus don't have electrolytic capacitors like the 90-97, so don't suffer from the leaking capacitor/corrosion problems.

Better pics would help though.

it seamed like it was because the color of it is different from everywhere else on the board but hmmm you learn somthing new everyday. dont mean to thread jack but what kind of capacitors do the 98/99's have? btw i love what your doing with the beta releases

 

[Ceddy]

How do you adjust the ISC?
I Just put a new ISC motor in there, I have installed and reinstalled that thing so many times now.
Is there a certain way they have to go in?
I am waiting for my boost leak tester arrive.
--------
I just put the computer back in, thats all the photos I have of the ECU. You can enlarge them.
The ECU is off of a 98 GST.

You have to center the ISC if a new one is installed. Check the FSM or search for a FAQ. You have to put the ecu in ISC adjust mode with a logger/scantool.
(Called Speed Adj. Screw Mode in EvoScan)

it seamed like it was because the color of it is different from everywhere else on the board but hmmm you learn somthing new everyday. dont mean to thread jack but what kind of capacitors do the 98/99's have? btw i love what your doing with the beta releases

I believe they are SMD Ceramic type, but not 100% sure. Steve(his username here) would probably know.

The one big backup capacitor is electrolytic type, I think, but it is a high grade version. I have yet to see any capacitor problems on any of the 98+ DSM and Evo ecus. The only problems the newer ecus seem to have is blowing up drivers if shorted out, but all ecus are susceptible to this.

 

[davidalindsey]

I have a OBDLink Scan Tool.
Do you know how I would have the ecu in "ISC adjust mode" with this scantool?
Thank you for your help.

 

[Ceddy]

I have a OBDLink Scan Tool.
Do you know how I would have the ecu in "ISC adjust mode" with this scantool?
Thank you for your help.

Probably not, its a MUT(Mitsubishi) protocol command.

 

[bryanwheat]

I'd be willing to bet that the throttle cable is to tight, there is carbon on the throttle plate causing it to not close properly, or that the biss isn't set correctly.

 

[steve]

I believe they are SMD Ceramic type, but not 100% sure. Steve(his username here) would probably know.

The one big backup capacitor is electrolytic type, I think, but it is a high grade version. I have yet to see any capacitor problems on any of the 98+ DSM and Evo ecus. The only problems the newer ecus seem to have is blowing up drivers if shorted out, but all ecus are susceptible to this.

Most of the capacitors on the ECU are ceramic SMD parts but there are several other types used including the SMD electrolytic on the top of the board. Anything with a part number starting with C is a capacitor, R = resistor, D = diode, Q = transistor.

You really can't see anything but the worst type of damage, something burned up, by looking at the board anymore. Electrolytic caps all have a finite life but I think it will be a while yet before we see any problems with the 98/99 ECUs. It's only been the past year that I've started seeing and problems with the caps on the earlier 2G ECUs.

 

[Ceddy]

Thanks, Steve.

Good info.

 

[1995gsx20g]

Most of the capacitors on the ECU are ceramic SMD parts but there are several other types used including the SMD electrolytic on the top of the board. Anything with a part number starting with C is a capacitor, R = resistor, D = diode, Q = transistor.

You really can't see anything but the worst type of damage, something burned up, by looking at the board anymore. Electrolytic caps all have a finite life but I think it will be a while yet before we see any problems with the 98/99 ECUs. It's only been the past year that I've started seeing and problems with the caps on the earlier 2G ECUs.

definitely good info to know. thanks steve and ceddy