Braineack

iTrader: (62)

and if they line up that perfectly it tends to me it's not correct, as the intake cam in that case would be off at least 1 tooth.

cliffs: the OP's timing is correct and shouldn't be touched.

hornetball

iTrader: (4)

??

Unless he's switched to sequential injection, the injectors just run off duty cycle and aren't timed to the engine.

Joe Perez

iTrader: (8)

?!?!?!

The injectors are absolutely timed to the engine, regardless of whether batch or sequential operation is in use.

That said, the firing angle of the injectors is almost totally inconsequential. Outside of idle, you'd be hard-pressed to identify a 90° change in injector timing.


Assuming the OP is using a Megasquirt (I don't remember that question being directly answered), I can pretty much guarantee that the coils are reversed. This is easy to do, especially on the NAs, because the build documentation that most everyone follows is reversed, which gets cancelled out by the fact that the default CAS settings which DIY specifies are ALSO reversed.


Put the CAS back where it belongs, flip the plug wires between the two coils, and the engine will start.

hornetball

iTrader: (4)

So, that's two votes. Anyone else?

hornetball

iTrader: (4)

Time for a threadjack!

I just want to make sure my understanding is correct.

First, as you correctly pointed out, we don't know what OP's setup is. However, in one picture it looks like he has stock coils, so I assumed that he was running wasted spark and batch fire.

My understanding of batch fire is that multiple injector are fired at the same time for a certain pulse-width duration under ECU control. The timing of the batch fire signal does not necessarily correspond to an intake valve being open (and, in fact, could only have this relationship for one injector of the batch). I'll certainly defer to your knowledge on this -- you've looked at MS signals on a scope, I haven't. Just trying to make sure I have a correct understanding.

Joe Perez

iTrader: (8)

You are correct that multiple injectors are fired simultaneously in batch-fire mode.

It would be incorrect, however, to posit that the injector firings are not timed to the engine. There is an absolute phase-relationship between the injector firings and the engine rotation. The timing is (somewhat) optimized to correlate with the intake cycles of the paired cylinders, albeit with one valve opening 180° after the other (as opposed to 360°, as would be the case is the injectors and coils were paired similarly.)

This is the reason that the injectors are paired differently from the coils. It never made sense to me until I actually looked at the scope traces and overlaid the TDC positions, and then it clicked. The injectors are paired on cylinders which fire adjacent to one another.

hornetball

iTrader: (4)

So, a bastardized sequential approximation. Interesting.

MicaCeli

iTrader: (1)

yes thats why I posted a better picture of the actual marks on the tooth that is supposed to lighn up cam cover.

M.net...what else can I say.

Joe Perez

iTrader: (8)

Right, which is why the MS's default batch-mode puzzles me so very greatly.

Every two-channel inline 4 I've ever seen has been paired like the Miata, with 1/3 and 2/4. And yet the batch-injection mode on ALL Megasquirts (1, 2 and 3) fires each of the two injector banks a minimum of TWICE per engine cycle, and there's no way to work around this. As a result, it is completely impossible to correctly align the injection angle on a 1.6 Miata using a traditional MS. (1.8 owners can work around this by pairing their injector 1/4 and 1/2 to match the firing order.)

With the MS3X/Pro, you can work around this by lying to the ECU and telling it to run 4 channel sequential, but connecting only to two of the injector lines. (I can't remember which two align correctly at the moment), and thus match the OEM config.

Or you can re-wire the car for sequential.

Braineack

iTrader: (62)

words that are over my head because I don't want to think:

The Miata wiring was the original source of the "MS2/Extra 2.x semi sequential settings" which is now called sequenced batch fire in MS3.

This allows a repeatable sequence but allows "2 sq alt"

It is called "Injector Sequence" on the Advanced menu.

The "start" value will be set to 0 or 1. The "mask" allows a form of rudimentary injector timing.

What it does is force the batch fire fuel to align on a particular cylinder for more repeatable results.

Joe Perez

iTrader: (8)

It's still wrong (relative to OEM wiring on a vehicle originally built with two-channel injection on an inline 4) because 2 squirts per cycle.

That is the very heart of the problem.

The 2 squirts thing is fine if you're downgrading a car originally wired for full-sequential (so long as you know to wire it "incorrectly" relative to OEM) and you also don't mind that you're doubling your injector dead-time and thus throwing away fuel resolution.

Braineack

iTrader: (62)

full-sequential like a boss over here.

Joe Perez

iTrader: (8)

Yup. Re-wired my '90 for full-sequential as well.

I just find it odd that the owner of a '90-'93 Miata (or any car originally delivered with 2 channel injection) cannot properly phase their injectors on a Megasquirt which also has two injector channels, simply because the damned software cannot be made to understand the concept of ONE SQUIRT PER CYCLE.

hornetball

iTrader: (4)

It sounds like the MS designers originally thought that the fuel injectors were wired together the same way as the wasted-spark coils. If that were the case, then two squirts per cycle could be aligned so one of the squirts was phased to the intake valve being opened on each cylinder. Alas, it's not the case. But what if you changed the fuel injector connectors around to align with the ignition system?

I look at it this way because dinosaur:
1. Better than a carburetor.
2. Better than throttle-body injection.
3. I like how my car runs, or at least I did before Joe illuminated me. Ignorance WAS bliss.

Can I have a dinosaur smiley?

Joe Perez

iTrader: (8)

The original MS design had no ignition controls at all. It was intended to be used with throttle-body-injection and a distributor, as an upgrade for carbureted American V8s using the same TBI hardware which was common in the 80s.

Everything which came after that, included wasted-spark ignition, was a hack added on afterwards.

hornetball

iTrader: (4)

I need to MS my Fury.

LOL at the dino.

Joe Perez

iTrader: (8)

Yeah, that's pretty much what it was designed for originally. Megasquirt didn't have ignition control of any kind in the original design, hence the name. The ECU that we now know as "Megasquirt" was more properly called "MegaSquirt-n-Spark" back then, as it was a mod which allowed for one channel of ignition control (still required a distributor, but timing was placed under computer control rather than being purely mechanical.)



They're actually a decent company. I've bought a lot of little stuff from them- HLAs, timing belt kits, etc.

MicaCeli

iTrader: (1)

You get this thing working yet?

claurence42

Hey guys sorry I'll update in case anyone else has this problem, my problem was that the CAS was flipped 180 degrees.... on the back of the motor there is two holes for the CAS adjustment screw, but you only use one. Thank you guys for your help!

Braineack

iTrader: (62)

wait, wut?!