Rebuilt ECU, now low idle

[fixkick]

IAC is bottom thing with water hose and welsh plug.
ISC is top things with 2 pin connector (ECU runs idle hot,  all the time)
injector O-ring pair not cracked, wow 28 years is  2nd wonder of the world not, really, see leak test above.

elaboration on this car this ECU and old EFI systems brick dumb they are.(then back to 1988 cars ECU are dumb and slow CPU and is why it is dumb that 1 thing)
transmissions aside, spark aside , carbon core spark wires are junk, get mag core wires for  even stronger spark.
spark timing not off,  150,000 mile slipped timing cam belt no changed at 60k per the book and the book does not lie,  as did it tell you spark wires at 60k for carbon crap.
one more given: compression is at 160psi not 50. cat not metal (if engine has full power cat is not melted)
if you think 40HP is full power it is not,80HP is. (only driving a good Sidekick answers this)8v

just EFI.  (topic)
think of ECU as 3 or 4 ECU's it is really they are called major modes.

1: cranking, is a very special mode,  due to VACUUM huge nasty bouncing actions, the MAP sensor is useless. here,  and is prime sensor here. but no now.
that means that the air supply now is UNKNOWN,  so is fixed in memory of the ECU. it knows the air supply is fixed by 3 devices, and ASSUMES that. (addition)
If the air is missing it must flood (or goes horrible rich) and wants to STALL, no engine runs lacking air (oxygen)
2:then when the crank shaft hits about 300 RPM the ECU detects (OMG) Im running now, and the MAP goes ONLINE. ( it waits for stable vacuum + rpm)

if the MAP sees no air supply (crazy high vacuum is that) it too will get lost,  setting very very very tiny injections and lean and stalls. 

3:then there is hot RUN mode and #4:last acceleration mode hot and cold. all very very different and can be thought of as 4 ECUs.  for clear diagnose.

so if hard to crank and start look for air missing.
if after start 1500 RPM is missing ISC dead, this will never end.


the IAC can be tested in hot pan of water at 180f as it opens at 150f (starts) and opens fully at 180f and must, or starting will never ever be fun.
the IAC has wax pellet inside, just like water thermostat has,
but lasts longer that 10 years,  of the latter, after 20 years of 20,000 thermal cycles it dies. most would be 40,000 cycles 4 trips a day .
as many things do. even that old DP.

1 question are spark plugs wanting to foul out, with carbon? or  green  antifreeze  or soaked in raw gas?) spark plug reading tests, worked in 1900 year to 2020. all valid, but not lead fouled that is gone. just that.  

now monkey rigged cars:
seem these vast times
car run in limphome for 5 years, or worse  backup mode
the PO a monkey , does evil things,  not fixing true cause, but tries to hide it by messing with all screws marked do not touch. (all 3 of them)
one more on a 16valve G16 we saw a guy that jammed bamboo slivers inside the FPR, valve,  to raise fuel pressure over spec to hid clogged injectors. wow, that was hard to prove but a fuel pressure gauge,yah did.

yah, stuff like that, is crazy common on old cars for sure 28 years old. seen every dirty trick in the book me, but love to see more, love to  crazy stuff, for fun.

wars are won by doing monkey rigs (jerry rigs)  and I like to see what they did.  Bailing wire, Sealing wax and the like.
not saying yours is, ok, just to be aware of it and the CEL lamp removed bull.   like that.
we already see wrong ECU, so we know the PO was , as they say a fancy dancer. " walk on the wild side"?

cheers and good luck, my topic today, lost AIR.