motor stumbles after it warms up

[fixkick]

as we all know engine swaps are very very hard to do and diagnose.
after all in most cases, the helper has no idea, what is there, now, or what is not there now.
and the ECU on most these cars go wonky, with wrong parts.
good luck and cheers !!!

[Terebit]

So; after letting the Samurai sit over the winter, I'm finally getting back to it. I'll either figure this problem out or I'll give up and swap in a 1.6, complete with new ECU and updated wiring harness.

It starts and runs, but lacks power and sucks gas. It's clearly running too rich and won't idle (dies) after it warms up a little.

To recap what I know:
88.5 Samurai 5 speed MT 4WD
1.3L Engine - G13F-XXXXXX
TBI (unknown - probably from '90 G16A) with intake & sensors
ECU - 60A31 = 89/90 (paint marking from salvage yard says 89/90 Tracker MT)
Distributer with vacuum advance (spark not run by ECU)
Wiring harness looks like from 1.6 (connects to TBI and sensors, but seems to have some unique connections to the ECU)
Things gone = EGR and all associated parts [VSV, dash pot], no CAT, NAG switch removed.

Things checked - timing good, fuel pressure good
Things new - O2 sensor, fuel injector, (sspence81 also replaced dizzy cap, rotor, plugs, wires and the ECT)

Fixed missing (not connected) wires to DLC [A15 and A9] and now get code 12 only. (Diagnostic switch terminal bypassed [jumper doesn't trigger codes], but diag fuse in place will give codes). Code 12 only for now.

Still not running right. Will start testing all sensors and fueling controls tomorrow. Will also note position of all wires connected to ECU [just for general information].

[fixkick]

yes the Frankingsammi.
how to make the G16a ECU like a G13 engine.?
the ECU is tuned for 300cc more, that is a fact, it has tables to run only 1.3L ,for speed density ECU.
the tables assume full 1600cc displacement is there, and fuels based on that, and map and IAT readings.
The ECU uses those table as part of the calculations for , air flow. so if air flow is wrong (it will be) then it will go rich, (low flow, but ECU assumes way more ,( via table) results in rich.
sparks ok? means advance works to spec.?
the MAP based engines are not accurate with wrong displacement.
why not run SAMMI parts on a SAMMI engine, G13 engine needs G13 EFI systems. (ecu and all matching parts)

the alternate is a liar box. (called a Piggyback by turbo guys)
a box that makes the MAP lie by 300 cc's.
reads lower by 300cc.

my joke now, your engine lacks, a whole 300cc dirt bike engine , (sizes) and is non trivial. that) a loss of 15hp worth of displacement.
one could measure every pin on that ECU ?
and see the page for that in the FSM book and see if some pins read wrong.
but the one pin that fill be hard to figure is MAP. (and o2)

that is every idea I have (not putting in g16)