Substitutions of ECU parts.         

Many parts are no longer made after only 15 years., Mitsubishi parts , in particular.  This page is theory and for the desperate. (It can be done, by matching the spec. of the original transistor)
The Cap's can be bought at any electronics store or  distributor.
Any entry level tech can replace them, even a TV repair shop.  Any Ham Radio op.  USING ESD protective methods.
MCM Electronics  ( has carried Japanese transistors since 70s , like no other )
Newark , owner of MCM
Mouser  ( I like their  lightning fast, fully automated shipping !)
Digikey  (Google them, they are BIG TIME sources, in N.America)
If you can't find an injector driver , try some of these.
My stock ECI injector  driver was a 2SD1415  an NPN bipolar Silicon transistor used by Mitsubishi ( a super beta part a "darlington")


Source 2

Source3   from the pinball wizards. 85 cents !

That pesky corner cap. (did  it explode? dry out, leak, or rupture) { A love to fail part if ever 80-95}
47uf = 50uf  ( yes, you can go higher, if it fits.)  ( spec on these is loose. -20% to +80% )   38uf lowest DMM meter reading.  This is the Capacitance in micro Farads or  1E-6 farads.
My corner cap on some ECU are 100uf at 50v.   (meter reads at least 80uf or it's bad)
50vdc and 63v are commonly the same  and is max working voltage( I have ECU's identical with both values used)  (keep in mind, the corner cap must sustain all car 12v power noise and spikes and are not trivial)
Do not use lower 16v or 25v parts for 50v or anything below marked part.  (non main caps, are so marked)  (however the 63v part , you can use 50v or 75v)
Get the lowest ESR rating you can find. but is not critical.
Get the highest Temperature rating which is 105C.
What ever you buy, will work great, considering  yours is dead open.  Even cheap  RadioShack  parts will work well. For a year at least. (in a pinch)
Do clean up the acid spills  (water and bicarb mixed)
Do neutralize said acid and correct all acid damage to circuit traces, with jumper straps (bare wire) if open circuit now ,due to acid etching.

Not all ECU's can be repaired,  the Microprocessor has a ROM and is programmed by Mitsubishi, and is not available.
Some ECU can burn up, or get hit with lightning, or be soaked in brackish water (salt?) ( yes, I've seen every type of failure !)
Or Collision damage, unlimited. (damage and cracks of any size or locations even inside components)
But we can fix all open traces on the PCB, and repair all bad CAPS and most, if not all transistors.
ECU with blown up HYBRIDS , are NOT SOLD.
If ECU gets wet , bake it at 120F , and pray.
The microprocessor is not replaceable with out the ROM code from Suzuki,  and where would you get that?  (a major hacking project , that would be)

The SIP'S dead ?  (single inline packaged transistor array)  Are no longer made! As are the SIP Hybrids.
This subs. link below, is pure theory, I have not tried it yet. (one guy is trying it  now)
S.I.P. Transistors substitutes?  M526x   here.
Each driver , on the board (a transitor) drives each output, all relays, all solenoids, all injectors. All can be repaired. Each driver is documented on my ECU page.

Many of the original discrete transistors, can still be bought, would wide.
Get the part number off the devices and search for it , you may find it.

Some simple parts are not sold , like the CE1F3.

You may substitute other transistors for this  tiny, but powerful part, and cheap.  80cents to $2 each
For Obsolete CE1F3 part.  (experimental topic)    typical of TCC relay driver !

This orig. 60v, 2 amp part is designed to drive inductive loads. and is a super beta part (a Darlington, or ?)
This ZVN part substitution will withstand the coils inductive back kicks as the mfg says. 25 mJ rated.  See appl. guide here.
Is designed for automotive (says IDEAL) and will drive .6amp relays no problem. Can withstand HUGE load Dumps.
It uses a zener  body diode inside the ZVN part  that eats up to 25mJ energy, for breakfast. (from coil kick-backs)
Orig on left, new on the right.
      subs.  to this ? >>
ZVN4306  Data sheet is here.  

The 16v ECU uses this lil' bugger ! for, CEL, TCC, EGR, EVAP, and the fuel pump driver.  (ouch)

This part is used on newer cars.  (advanced hacking here , ok? )
One of the best low cost and simple injection drivers, is  by IR, or International Rectifier.
Can be substituted for old drivers.  (needs 4vdc on gate to turn on, so will need a driver)
and a  27 ohm  series gate resistor for DS(crss ) to stop capacitance self gating issues with inductive loads.
Best, is to drive the below FET  with MOS driver like the MC34151P chip, with or with out inversion, as applicable. (ours needs no inversion)
Note clamp diode and avalanching feature !
     or even more powerful this one.

Secret Japnaness transistor codes: 
Jap. Transistor part number, prefixes: (non Jedec)

2SA.... (PNP)
2SB.... (PNP, power)
2SC.... (NPN and NPN HF power)
2SD.... (NPN, power)
2SJ.... (P channel FET)
From the data sheet collection of HITACHI, NEC, SONY, TOSHIBA

2SK.... (N channel FET)
From  the data sheet collection of HITACHI, MATSUSHITA, MITSUBISHI, NEC, ROHM, SONY, TOSHIBA
3SK.... (N channel DGMOSFET)
In the data sheet collection of NEC and SONY

Example , I pull the Injector driver transistor it reads   D1415  I add  2S and get 2SD1415 and am correct.

All comments assumes you don't have a cache of dead ECU's laying about, ready to cannibalize.!  

rev 1   ++++ 5-18 -2011  ,