Samurai TBI | No Injector Pulse

[fixkick]

the pump must run for 3 seconds key on, if not find out why, fuel pump relay bad or FI fuse blown or IGcoil fuse blown.
just listen as you key on for the 3 second fuel prime sound.
im sure it is  ok, and  you checked PSI but just hearing that sound tells me the priming pulse happened, and any relays that chatter , ECU CAPS are bad. 
Im always looking for other odd things any ECU does in the logic, if injectors are dead, look for other oddities.
like, CEL dead. or
blinks out code 12 and repeats or as it repeats,  halts mid flashing code sequence, this is ECU crashing for bad CAPs. seen that many times. and relay chatter sounds.

The pump definitely runs with key on. CEL is good, no funny relay chatter or anything. The code 12 blinks 12, then pauses then repeats 12, pauses, repeats, etc. That is normal right?

ah gees, forgot to say is 5vdc pin on ECU ok> seen also on 5vdc pin of TPS. (key on) Im sure it is but needs to be checked first always. anytime ECU messes up.

CEL Ok,  12  ok and repeat good. pump and pressure good.
the TPS if its ground wire is cut /broken , not a 0vdc, there will be no injection.
the NOID test m must be done (best) with injector pulled, and NOID lamp there,
and not LED NOID the LED flashes faster that humans can see,  5 milliseconds is way to fast for humans.
that is why scopes work best but a  real tungsten lamp bulb  (as  sold for years now, real noid lamps) 
I use a 25MA lamp do to my fear of overloaded the transistors. for example a tail lamp uses 40 times more current at 1Amp.

noid dead across the 2 pins. test 1 fails.

to see which transistor is bad.?
connect noid pin    battery neg lug., ground and other pin pin of noid to RED injector wire only. (NPN wire) red.
it must flash. if yes transistor is good.
now the PNP trans test.
then test 2, (3 really) connect , noid pin 1 to yellow injector wire, (low side transistor) and other noid to battery wire plus.
the noid flashes now proving down side transistor is good. PNP


yes bipolar NPN/PNP transistors can be tested with dmm, using diode test mode
this is true 1991 up, never on sammi.
as you can see R225 must not be burned open.




91 TBI flashing , NOID on yellow/red  ,  the tungsten wire in bulb is very slow to cool down and does not actually flash.




this fast pulse is too fast to see using any LED,   0.7MS is super fast to any eye the scope allows this to be seen this fast pulse. (CRT persistence magic)



last is I made this drawing below, using vast scope readings.  cranking is 2.5mS injector pulse.  0.0025 seconds, fast. and 300RPM  x4 is rate.
1/200th second,  is a blink most folks can see (eye/brain).  5mS. is that. (the brain also learns this (eye thing), no 2 persons  are the same)


as you see the ECU goes to great effort not to overheat the coil in the injector or the 2 transistors.