Help on 2 Injectors not firing
08-10-2009, 08:28 PM
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Help on 2 Injectors not firing I've got a 99 ls1 4l60e, program and harness from speartech. I bought the whole package (engine, trans, ecu, harness) from someone who was going to install this in another car.
I've got the car running on 6 cylinders and I've come down to 2 injectors not firing. I have continuity in the wires from injector to the ecu, I've got voltage going to the injector, I've got 13 ohms resistance in the the injector itself. Is this a program issue maybe it lost the driver for these 2 injectors or am I going in the totally wrong direction? Also on a side note the trans won't shift out of first.
This whole package has been sitting for about 2 years I've just now got around to building this car.
If it is a programming problem has anyone dealt with speartech in a situation like this? I don't know if they will honor their program with me not being the original purchaser.
thanks
I've got the car running on 6 cylinders and I've come down to 2 injectors not firing. I have continuity in the wires from injector to the ecu, I've got voltage going to the injector, I've got 13 ohms resistance in the the injector itself. Is this a program issue maybe it lost the driver for these 2 injectors or am I going in the totally wrong direction? Also on a side note the trans won't shift out of first.
This whole package has been sitting for about 2 years I've just now got around to building this car.
If it is a programming problem has anyone dealt with speartech in a situation like this? I don't know if they will honor their program with me not being the original purchaser.
thanks
08-10-2009, 09:20 PM
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Think in terms of the current loop, for things that have
to do work.
You need high side (voltage) and low side (ground)
for the injector solenoid to move. Measure both
voltages against a known good reference ground.
High side should read same as IGN, low side will
be a duty-cycle average of IGN voltage less some
small injector driver voltage drop. At idle (if it idles)
the duty is very low and you might not see the
difference, but you should see at least hundred-mV
voltage measuring across the injector, by the meter.
A "noid light" might be handy. An old-school pick-light
across injector wires should light dimly.
I cut up an old wiring harness and picked off one of
the injector sockets, soldered alligator clips to it, and
now I have a little test lead. You could hear the click
of the injector by putting battery voltage across it.
No click, even if ohms are good, means stuck. A
"basket" motor could sure have gummed up one or
two.
Swapping positions is a way to narrow that down.
You may want to verify which year the PCM is from,
and that the SpearTech harness is the right one for
that. Pin assignments move around year to year and
it's not inconceivable that you got a bundle of parts
that only look compatible.
to do work.
You need high side (voltage) and low side (ground)
for the injector solenoid to move. Measure both
voltages against a known good reference ground.
High side should read same as IGN, low side will
be a duty-cycle average of IGN voltage less some
small injector driver voltage drop. At idle (if it idles)
the duty is very low and you might not see the
difference, but you should see at least hundred-mV
voltage measuring across the injector, by the meter.
A "noid light" might be handy. An old-school pick-light
across injector wires should light dimly.
I cut up an old wiring harness and picked off one of
the injector sockets, soldered alligator clips to it, and
now I have a little test lead. You could hear the click
of the injector by putting battery voltage across it.
No click, even if ohms are good, means stuck. A
"basket" motor could sure have gummed up one or
two.
Swapping positions is a way to narrow that down.
You may want to verify which year the PCM is from,
and that the SpearTech harness is the right one for
that. Pin assignments move around year to year and
it's not inconceivable that you got a bundle of parts
that only look compatible.
