1990 tracker -no start FI fuse?

[fixkick]

I replaced the ECU and the truck runs! Obviously the ecu has something more than leaky caps and the suspect zener diode. I want to fix this ecu and keep it as a spare in my boony box. I'm a bit leery of going out on the trails after this event. What can you offer as next component to replace? I'm interested in fixing it myself ( was quite satisfied with my soldering skills - but struggled with the "desoldering" I think this "solder wick"  thing maybe helpful.  If I can't, then it goes to cardone or other  repair house for test/repair. I still find it amazing that it was running perfect and while idling in the garage it just quit!
again -any help is appreciated. As a side note the cold idle is about 2k rpm. Is that a sign of something off or simply an adjustment? once wamned up the idle is about 750 -ish.
Thanks rjm

good news,  and amazing for a car 30 years old that still runs.
solder suckers and solder wick, both work or as a team. for sure.

the 2k is from the IAC, cold air supply, when cold it opens. and is 30 years old. the drift with age and it is amazing it still  works all, 1500 is more common but the iAC (inside base of Throttle body)
varies by water temperatures, only. 
The IAC has a wax pellet inside just like coolant thermostat has and no thermostat made lasts 30year, 7  is par  on STAT.'s
The ECU has may parts that are not made nor sold now. zener  yes, on all.
The Big transistors are sold, but the 4 transistors in SIP package are not (VSV drivers)
Most Big house repair shops cannibalize old ECU to fix 1.  in many cases.
Not only that but 2 ECU in hand one can see copper trace damage,  after all the acid eats up the evidence of what was there before.
There are no schematics from suz nor Fab drawings on PCB layout.
The if you have burn damage most of those are hopeless, or make good Cannibalized targets for rare parts.

if the damage is huge the BIG repair house will reject it as a core. (no core credit)

this 90 ECU does not create or control spark (nor advance), this ECU only injects (and runs vsv etc)
That means having good spark means nothing for this ECU,  at all. zero. it is  fuel injection controller.

your ECU old is dead, fully dead. what I do with dead is check power pins on all larger chips. (not transistors) only IC chips.
if VCC or VDD pins are dead on any the power pins the supply is dead, (cap acid damage is mostly the cause eating up traces, or burn damaged.)
we call those VRM's voltage reg . modules.  we test those too.  The ECU has 2 of these at least.

in electronics checking power is first 5vdc in this case.

good luck finding a spare good.  at least they can be had , unlike Samurai, ECU,  ouch.