straight 6 - going back to basics

[Mos]

I think this one can do up to 30,000rpm (in half degree steps )

[oldcorollas]

=2.8microseconds, so probably has res of 1us? but faster counting than that to keep track..

(fwiw, MS2 has fuel res of 1us, and timing res of 0.1deg, but i dunno what rpm it can do that up to)

[JZA70 R]

tonight i switched 2 injector plugs around from two different batches, motor barely ran, hardly idled and stalled shortly after. didnt want to rev at all.

ive also taken a look at the translated 1JZ-GTE wiring diagram that is floating around, it shows you how the injectors are wired and what their colours are, they show all six black wires merging into one that returns to the ignition negative switching... someone want to explain that?

also who wants to take a guess at whether polarity is cruicial on a sensor for example a cam position sensor despite it using alternating current?

[big_zop]

also who wants to take a guess at whether polarity is cruicial on a sensor for example a cam position sensor despite it using alternating current?

Umm... all cars run on DC. The alternators output is regulated to a set voltage (I would say 12V but i know its not).

So yes, polarity would make a big difference and hopfully you dont end up switching a power feed to the ecu or boom...

[Mos]

tonight i switched 2 injector plugs around from two different batches, motor barely ran, hardly idled and stalled shortly after. didnt want to rev at all.

Okay

ive also taken a look at the translated 1JZ-GTE wiring diagram that is floating around, it shows you how the injectors are wired and what their colours are, they show all six black wires merging into one that returns to the ignition negative switching... someone want to explain that?

It's not ignition negative switching - it's ignition positive switching *sigh*....
Dude, I eat, shit and breathe toyota wiring diagrams - while I do occasionally get things wrong, this one is so basic that you need to turn off what you think it's doing and listen to what everyone is telling you and interpret the diagrams in the context of what everyone is telling you, not what you think is happening!

also who wants to take a guess at whether polarity is cruicial on a sensor for example a cam position sensor despite it using alternating current?

I don't need to take a guess - yes, it's crucial.
The cam position sensor itself doesn't *use* alternating current, it *produces* an alternating *voltage*. The shape and direction of this voltage is crucial to the ECU triggering properly - it needs to see a negative edge going through a zero crossing to trigger.

I'd strongly suggest you read the autoshop articles on EFI to improve your understanding of how it all works.

Mos.

[JZA70 R]

lol man my auto electrician must be on drugs. he told me its AC???

wish i knew all this stuff myself, still learning electronics if you havent guessed haha.

[LeeRoy]

tonight i switched 2 injector plugs around from two different batches, motor barely ran, hardly idled and stalled shortly after. didnt want to rev at all.

This is because theyre not firing at the same time. If 1 & 2 fire at the same time then they can be swapped hence why your engine failed to run.

ive also taken a look at the translated 1JZ-GTE wiring diagram that is floating around, it shows you how the injectors are wired and what their colours are, they show all six black wires merging into one that returns to the ignition negative switching... someone want to explain that?

Most toyota stuff grounds through the switch (ecu in this case) - making it negatively switched.
This serves a few purposes;
- lower voltage drop
- less heat through switches (less current)

In the case of the ECU if you were powering everything you would need a mofo fuse, and if this fuse blew it would take you a whole load longer to diagnose a wiring fault. By splitting it up you seperate the circuits, allowing them to be fused individually. It also lowers the current going through the ECU.

[JZA70 R]

This is because theyre not firing at the same time. If 1 & 2 fire at the same time then they can be swapped hence why your engine failed to run.

logic was telling me this was the case, but Mos insisted it would work... hence why i tried it.

[oldcorollas]

what is wrong with your car so that it doesn't work?
what did you do? were the injectors still firing after you wapped them around? maybe you didn't push the plugs on enough?

fwiw, when i installed my megasquirt on a 4cyl, it fires 2 batches of two injectors. i swapped them all around to see if it made a difference.... no difference at all.

just look up the document Mos indicated and READ. it tells you very plainly how things work.

maybe your auto elec was dumbing it down for you?
the output kind of looks like "AC" because it goes above and below 0 volts, but it is the output of ANY coil moving past a magnet.....

[LeeRoy]

logic was telling me this was the case, but Mos insisted it would work... hence why i tried it.

You probably misread. Mos would have been infering what i've said above.

[Mos]

lol man my auto electrician must be on drugs. he told me its AC???

The signal is of an alternating nature, as opposed to something like TPS or MAP which is a signal of a steady nature. The closest nomeclatures that people (slightly) understand is AC or DC, so maybe he was simplifying it.

wish i knew all this stuff myself, still learning electronics if you havent guessed haha.

Not trying to have too big a dig at you, but it doesn't help to guess [wrongly] and then ignore people telling you that you guessed wrongly... Change your guess - don't try to change the experience of others.
Read the autoshop docs!! now!!! before posting again

This is because theyre not firing at the same time. If 1 & 2 fire at the same time then they can be swapped hence why your engine failed to run.

No no, I meant that you can arbitrarily swap injectors around and it *should* work. I'm not convinced that the lack of working was due to just injectors being swapped around, but I cbf arguing

It also lowers the current going through the ECU.

No, not really. It reduces the current that ECU must supply, but it doesn't reduce the current that must pass through the ECU. The power supply to an ECU is quite small, however the grounding connections are generally quite substantial, because a lot of current passes through them.

Mos.

(plane boarding, gotta go )