ECU, after transistors change...b8 y b17 no cut

[calo]

HI Again!!

I changed the transistors q101 y q102
I test the B8 and B17 pin with a light. Turn on, the fuel bomb cuts after 3 seconds but the light never turn off. So inyector will never stop.

any suggestions?

Best Regards from Argentina!

[fixkick]

welcome Argentina !
which p/n ECU. ?

[fixkick]

8v ECU, both transistors must be turned off keyon.

if the new transistors. have metal on the back side. (wrong kind, type)
this causes the collector pins to short to ground (heat sink metal)

you can find out which side is failing. using the same lamp
injector , unplugged.

Red wire B8 >>>> lamp >>>> ground (engine metal)
lamp should not glow keyon, and must flash cranking.
if either test fails there, the transistor is no good. (wrong type, or backwards)

yellow wire B17 >>>> lamp >>>> 12vdc battery post.
key on, no glow.
cranking it flashes, if either test fails, this transistor is bad.

[calo]

HI Again !!!!

Transistors blew again!!
But...
I discovered a short in one of the wires coming from the trunk. (A white-green wire from trunk fuse box)

I have to isolate it and find out where this short

thanks again and regards from Argentina!!

[fixkick]

truck? huh?
tell me where the wire is, and what it connects to. or just the exact spot of the harness, !
there is no truck on any sidekick
a cargo area yes. and hood (bonnet in UK)
the ECU feeds a dash harness and up to the engine bay, harness. (im sure you mean that.)

the 2 transistors only blow, with injector is shorted. less that 0.8 ohms (0.8 to 1.2 ohms is spec, DC resistance) DMM readings.
the wires are shorted together or to ground or to the battery plus power feed of any kind.
that is it, assuming the are correct transistors and mounted to heat sink with thermal compound. (and tight, to said sink)
one way to save it is to add a 7 amp fuse to the RED injector wire, close to the ECU. (it runs like this but no person ever tried to do a short on purpose to prove this, not crazy enough yet)
this fuse will blow, telling you the injector feed wire is shorted, some way.

run new wires from ECU and injector.
then you know the wires are good.
use 18gage wire.
use a fuse.
some harness shorts are near impossible to find, ( I can find them, but I have a mag scope probe that lets me do that) {shows direction of short too}

good luck , and happy kicking.

[calo]

My mistake!

A cable from the fusebox in the hood

Thanks!

[fixkick]

A white-green wire from cab fuse box. to the engine bay fuse box.
this is easy, its a MAIN power feed.

you have not posted, car make , model or engine options or transmission, in car. so is hard to help you.
so ill take a wild guess and say 1992 Suzuki Sidekick with TBI 8 valve engine and -56bxx ECU.

off my schematics page here is the 92-95 power distribution page.
http://www.fixkick.com/power-elect/95%20...istra1.pdf

Page 1.
white-green runs the whole ignition switch. all EFI , and FI, and spark.
if that wire gets cut and grounded out, you blow the 50 amp right fender fuse (called LINK B ) in the engine bay box, preventing a huge fire.

that wire, is big time important, it runs the whole show.

[calo]

A white-green wire from cab fuse box. to the engine bay fuse box.
this is easy, its a MAIN power feed.

you have not posted, car make , model or engine options or transmission, in car. so is hard to help you.
so ill take a wild guess and say 1992 Suzuki Sidekick with TBI 8 valve engine and -56bxx ECU.

off my schematics page here is the 92-95 power distribution page.
http://www.fixkick.com/power-elect/95%20...istra1.pdf

Page 1.
white-green runs the whole ignition switch. all EFI , and FI, and spark.
if that wire gets cut and grounded out, you blow the 50 amp right fender fuse (called LINK B ) in the engine bay box, preventing a huge fire.

that wire, is big time important, it runs the whole show.

All solved!!
I find the short, it is not the white-green. The alternator/regulator is shorted. I send it to repair and now is all right!
The kick is running like champ!!!
Now I have to order all the cables, accommodate the ecu and the internal fusebox

Thank you very very much!!!!!

Greatings from Argentina!!!
Calo

[fixkick]

that is common fail the alternator diodes short inside it.
i am very happy your car runs good now.

happy trails !