Second PC-Pro for E-Cool?

[ROZ]

In reading through the threads, it appears there's a second PC-Pro for the E-Cool 5th injector (I'm looking at hotside for Mk1 1.6 BTW). However the installation instructions only cover the installation of one unit onto the ECU, which presumably is the stock 4 injectors. There doesn't seem to be instructions for wiring in a second PCP for the 5th?

Can anyone clarify?

[Tom @ Fast Forward]

Everything comes pre-wired to a plug in harness. Both PC-Pors and the timing card (optional). All you do is plug it in.

The 1.6L Hotside kits for 90-93 have only 1 PC-Pro as it can run the E-Cool as well as the main injectors for the 90-93.

[ROZ]

What's the Pin Out for the one card/E-cool option?

How does the one card control e-cool on this installation while it doesn't on the coldsides?

Are the tuning instructions different, or is the 5th injector just used added to the other 4 as a way of adding more fuel - ie. what's the split between the main 4 and the 5th?

Hmmmm... lots of questions.....

[ROZ]

Tom
NB. Mine's a '96, but you confirmed in email that it's the same as above!

[Tom @ Fast Forward]

The main card and the E-Cool card are the same card. It just didn't have enough memory to run bothe functions. In the 1.6L, the injectors are batch fired instead of sequentially fired as in the 1.8L. That frees up half of the memory and leaves plenty of room for running both programs. The wiring is the same as with two cards as the same wires are used but all from the same card in your case.

Tuning instructions will be the same. Green, Yellow, Red, Yellow/Blue, Red/Blue for the main fuel and Green/Blue for the 5th injector.

[ROZ]

Cool - that makes it straightforward
For interest's sake, could someone explain batch and sequential fueling. I've probably got an idea, but I'm playing the "if-you've-got-a-daft-question-someone-else-wants-to-ask-it-too" card...:biggrin:

[Tom @ Fast Forward]

The ignition system has been batch fired from 1990 to 2005. That means that cylinders 1/4 fire every time 1 or 4 comes up for an ignition cycle and 2/3 fire every time 2 or 3 comes up for an ignition cycle. Fueling for the 90-93 works in a similar manner. Both injectors are fired every time either cylinder comes up for a intake cycle. One fires at the open intake valve and the other fires at the closed intake valve. Only this time it is cylinders 1/3 and 2/4 that fire together for fuel.

Starting in 1994 with the 1.8L engines, they went to sequential fuel where the cylinders fired individually as the intake cycle started. 4 individual circuits out of the ECU rather than 2. Taking twice the memory to drive them.

[ROZ]

Excellent. Thanks. :yes:

[John Miles]

One fires at the open intake valve and the other fires at the closed intake valve. Only this time it is cylinders 1/3 and 2/4 that fire together for fuel.

That's interesting - I didn't know they did that. Why doesn't that waste half the fuel and/or make it impossible to meter the mixture correctly?

[Tom @ Fast Forward]

Well, it doesn't waste fuel as the fuelis just sitting there waiting to be consumed. However, I would guess emissions bit them and made them move on to sequential. For those of you/us, we kind of get the same thing. On a STOCK Miata, at 7000 RPM, the intake valve is open for about 8.5 mS. However, the injector fires for about 13mS. Must be about 4.5mS of fuel with the valve closed, eh? :)

[John Miles]

Well, it doesn't waste fuel as the fuelis just sitting there waiting to be consumed. However, I would guess emissions bit them and made them move on to sequential. For those of you/us, we kind of get the same thing. On a STOCK Miata, at 7000 RPM, the intake valve is open for about 8.5 mS. However, the injector fires for about 13mS. Must be about 4.5mS of fuel with the valve closed, eh? :)

Makes sense, except it's not just fuel, right, it's the mixture of air and fuel that is sitting there waiting to be inducted into the combustion chamber. All the trouble that engineers take to optimize the intake runners seems wasted in light of this sloppiness.

I guess that's the idea behind the trend toward "direct injection," huh...

[Tom @ Fast Forward]

Spraying fuel on those red hot valves probably vaporizes that small amount of fuel pretty fast. That would aid in cooling the valves and mixing with the adjacent air. Vaporizing in that air also helps cool the air. Besides, it is only there for abour 3-4 mS. Then it is sucked in with the fresh air and fuel and the intake valve closes and it starts all over again.