extreme gross flooding (use WOT cranking , this causes ECU to cut all fuel)
this is easy to diagnose on any EFI car, even this car, with 1 injector, that can even be viewed.
it has 3 parts, (injector, ECU and sensors,) one of these 3 fail, (groups) it probably is not , fuel pressure 2 time normal, but we find all that doing TEST #1
test 1 is called a VISUAL leak down tests. first with just eyeball.
(factiod: TBI runs Great with no air horn, just dont suck in bugs, and for sure BOLTS/nuts/screws/washers LOL)
1: take off the air horn on top of the TB (throttle body, ) btw , the TB in your car is not the same as 91 to 95 years. different injector and body , and different ISC idle valve.
2:This car at 10 degr F acts as 91+ car, but no now its still late summer here, (87F here now) that means the injector Fuel PUMP on this car until cranked.
2a: so key on say 3 times see if injector leaks, with pump dead, (no cranking) sense the pump is dead now, no fuel possible, but good to check (wiring hacks reasoning)
2b: now crank the engine see injector squire, crank for up to 3 seconds, max (to avoid flooding) then release key and see if injector leaks NOW.
2c: lets say it leaks NOW, that is failure . discussed below.
2d: This test is WOT cranking,, and if it leaks cranking with foot wide open throttle, this is bad injector or bad ECU. but lets do the testing.
3: if the injector leaks fuel, then we unplug the injector connector next , if the leaking stops the injector is not the cause, (easy no? super easy, to do that)
I think test 2d is the best , above 10F out door temps.
4: if we find the leaking stops with injector connector pulled, then the ECU is bad.
I'd say off hand the ECU sensors are not bad if code 12, so why is ECU bad. that ends leaking with injector plug wire connector pulled.
we can test the sensors if you want with any cheap $20 DMM meter made. easy, ask. Here is your wiring, there. Are the Red or yellow injector wires molested in any way?
http://www.fixkick.com/INJECTORS/89/89-90schem1.jpg
well the ECU can be bad, it has 2 transistors that drive the 2 injector wires, many times we see other hackers here, that found 1 wire dead and hot wire it and sure car can start but floods.
the symptoms are cranks ok, but does not start, but floods. (use WOT cranking top clear floods) or even watch the injector doing that to see the injector cut all fuel at WOT.
the other way to test this as all MPI guys know , as all cars now are MPI , 4 or more injectors.
Now testing with real fuel pressure test, all mechanics know what leak down test is. (NOT GUESSING AND GOING BROKE)
the classic fuel pressure leak down test IS NEXT .
on THE 92-UP mpi CAR THE RAILS IS AT FULL PRESSURE, just key on. but not your car so needs more odd ways if testing (fools many a person)
The 10F rule fools most. (as does the all-in-on pump and main relay)
we key on and test fuel pressure on this car cranking or running, only. (the pump is dead, just key on, warm days)
34.1 to 39.8 PSI. cranking, this is SPEC>(and running spec)
if at 50 t0 60 PSI the fuel pressure reg is bad, FPR on the front of the TB , see it? they love to fail this old, 28 years old.
ok say you get 35psi, (varies by altitude this, unknown by me your location altitude) same pressure running, btw.
crank 3 seconds max. (best is 2nd person watching in all cases in to the TB air horn, huge pipe there removed)
then release the key, key, and turn to off, the pressure holds 1min, this too, is a FPR test, to make sure it does not leak, nor the 1 injector , as we looked at with eyes.
if the pressure falls fast, that means there is leak. (if the injector is dry the FPR is bad or the check-valve in the pump is bad)
if you saw the injector leak like mad?, yes, than BINGO, the cause of Injector leak down test failure is known by you.(well ECU or injector is)
spec is Residual test is 25 psi min. after 1 minute. (say 35 to 25psi in 1 minute flat or better, as better is holds higher)
if the injector stops leaking unplugged, the injector is not bad. (easy as pie test)
the only hard part is knowing when to look, and that answers is, 2 fold, just as you key off no leaks, and cranking wot , this is magical Unflood mode covered in the users guide.
When the TPS (TP pin or throttle angle pin (as we say today) is not at 1v but more closer to 4vdc this is wide open throttle the ECU sees that cracking and cuts the injector signals DEAD. (this logic is all hard coded in the ECU brain Firmware (ROM in this case)
the injector can be fully cleaned and tested here, $22
cheap, no need to send a fortune on TB so rare. the clean it and test it before and after, there is no guessing here, just do it. no huge cost $22 not $300
https://www.witchhunter.com/
the 91 plus year TBI is more easy to test
we key on get 35psi and no injector leaks. ever.
on your car, key on pressure will be 0 PSI , no pressure, and cant leak this test, due to no pressure , this and only this fact makes 89/90 tricky to test,
so crank it and release the key, at instant of key off, no leaks allowed (injector tip , eyes on)
or crank WOT, no injections allowed, now.
NOT SURE WHITE SMOKE, BLACK IS FUEL.
WHITE smells like burning oil is oil
white, smells sweet, like antifreeze is water leak blown haad gasket for far worse.
Step one is inspecting those 2 wire on the injector, see of others hacked here, no cuts on the 2 wires allowed, no splicing there allowed. ok? (RED AND YELLOW PAIR)
the only 2 sensors related, here are IS ECT and MAP.
if the ECT reads 2300 ohm at room temp its good
if the ECT read. 15,000 ohms at room temp this car will flood, (the ecu brain sees that and thinks omg, you live on the North Pool, Klondike and dumps HUGE FUEL)
The map is the same, it can read too high and EFI goes way rich or the vacuum hose is bad to it.
REFR:
http://www.fixkick.com/INJECTORS/pump.html
![[Image: 1_31_05_13_12_12_12.jpeg]](http://www.fixkick.com/bbs2/Suzuki-bbs/gallery/1_31_05_13_12_12_12.jpeg)