SanJoRX7

Jason-
Please review the attached doc and post it in the PFC instructions section if you think it'll be worthwhile. I think I nailed a number of items in it and have managed to consolidate quite a few points that are scattered throughout the forum. Besides all that, we can update it as time goes on, and it'll serve as a jumping off point for newbies.

Patrick

Others: Please read and comment on the doc so I can put everyone's input in to keep this as up to date and accurate as possible.

skunks

how to do you find out what map you are running?

under the boost section there are 2 settings, how do you switch between them?

SanJoRX7

To determine which map you're running, you'll first need to get a copy of at least one map...either the Base Mod, or the Base Stock. You'll have to compare them cell by cell to make the determination, unless you have a datalogit.

You can get the maps at the URL I provided in the how-to:
http://www.exorzero.com/skotx/powerfc/

...grab one or both of them and start comparing

As for switching boost...since there is no confirmation with the PFC, whichever setting your cursor is on when you hit the "Prev" key will be the one you're using. Same goes for every other value in the PFC...just be careful.

redbase

What do the wires that are clipped go to?

T24U

I think that what he's trying to say is that you must cut the harness connector that goes to the ECU, and splice the new PFC wiring into that one - replacing the original ECU. That's just my guess? There is not an adapter harness that comes with the PFC? That would make things super easy then. Just plug-and-play.

ech

SanJoRX7

No, there is no adapter. It might be a cool idea if someone needs an electronics class project, but otherwise, you can either clip the wires or just push the pins out of the harness (not easy to do, btw).

SanJoRX7

Oh, sorry, didn't add this...

There's no splicing involved. You clip the appropriate wires on the harness, cover them up for safety, then plug the harness into your PFC. That's all there is to it.

13brv3

Greetings,

I just got my new PFC, and there is an addition to the instructions for cutting wires. First, there's the usual 4 wires to cut. In addition, they now say the following:

"Cut the A/C out wire from the 22 pin connector (yellow/blue) and splice it into the A/C in wire in the same connector (purple). Do not remove the purple wire from the ECU."

The drawing that shows the harness now has handwritten notes showing the A/C in, and AC out wires. Has anyone else done this? Unless I hear otherwise, I guess I'll try it, perhaps later today.

Thanks,

SanJoRX7

Are the instructions to cut the AC wire included with the PFC straight from the factory? Mine didn't come with any such documentation (just the one about cutting the wires that I mentioned above). If you can get a picture of that documentation, I'll add it to the collection and try and figure out what it's all about. Anyone else know anything about it?

13brv3

OK, so you can't upload .tif files, and then it erases all the text you just typed... Grrrrrr

As I typed before my post was so rudely deleted, my PFC is new, and I just received it from RX-7.com about a week ago. There were three sheets of paper included.

One was folded up by itself, and is probably the same as what everyone else received. It has a drawing of the harness on the bottom, and shows only the 4 wires that are commonly cut.

Two other pages were folded up together. One was just like the one above, but the harness drawing now has two extra wires drawn in toward the right of the plug drawing. These are labeled A/C in, and A/C out. the other page is a text description of what you're supposed to cut, and splice.

The attachment (I hope), is a zip file, that included the two scanned pages with the A/C wire notes. I'm still debating on whether to do this now, or wait for confirmation. I really hate cutting wires on the stock harness.

Cheers,

SanJoRX7

My best guess is that this has something to do with the fans. I'll make a post to the rest of the PFC forum and reference this thread and see what people can tell me.

13brv3

Well, I installed it, and the instructions are wrong

(SHORT VERSION)

The A/C out wire that is shown as yellow/blue, is actually yellow/black. The location is correct, but the color is wrong. There is a yellow/blue wire right next to it, but that is the wrong wire.

(LONG VERSION)

I cut the 4 wires that are called out normally. They all matched the drawing, and so no problem.

Step two is to cut the "A/C out wire... (yellow/blue)", and splice it into the A/C in wire (purple). The purple wire is where it's shown in the drawing. Unfortunately, the A/C out wire that's listed as yellow/blue, is actually yellow/black on the harness. To confuse matters even more, the wire next to it is yellow/blue.

OK, so the question becomes- is the drawing pointing to the correct wire, and labeling it the wrong color, or is the color correct, and it's pointing to the wrong location?

Out came the manual, and wiring diagrams. The location that's pointed out by the APEX diagram for "A/C out", is terminal 1L in the Mazda wiring diagram. This is listed by Mazda as "AC relay", and the color is "Y/B". This has to be the correct wire, since it goes to the AC relay. It's also understandable, though unforgivable, that APEX might read Y/B as yellow/blue. In the wiring diagram, Mazda uses B to mean Black, and L to mean Blue. The yellow/blue wire next to the AC location is terminal 1N, which goes to a pressure/mileage switch.

Bottom line is that the car runs, and the AC works. Now I get to start reading all those posts about idle hunting (which it does with a vengeance), and hesitation off idle.

Cheers,

SanJoRX7

Here's page one of those .tif's in .gif format (my jpg's always end up being pretty huge, even when I scale them down with photoshop. PM me if you want the big mama jpgs).

SanJoRX7

And here's the second one, again, in .gif.

streetraceseven

the collors on my harness did not match the pin outs at all so i just went by the pin outs.

SanJoRX7

Also, I just got ahold of skotx, the guy who did the PFC map comparison tool referenced way above (that has since broken), and convinced him to rewrite it. He's just done so in PHP, so I will be hosting it on my server from now on, and I believe that he's working on Jason to get him to host it directly on the forum. At any rate, the one on my server is located here:

http://pb.kenjim.com/pfc/

Enjoy!

Patrick

books

iTrader: (8)

13brv stated "Cut the A/C out wire from the 22 pin connector (yellow/blue) and splice it into the A/C in wire in the same connector (purple). Do not remove the purple wire from the ECU."

which side (connector side or a/c side) of the cut wire do you splice into the A/C in wire?

thanks Dave

13brv3

The quote is from the actual instructions that came with the unit. Remember that they are incorrect on the wire color. The A/C out wire is Yellow/Black.

Here's how it all seems to work.

The A/C in wire (purple) is coming from the A/C switch, which also must be wired together with the blower switch. So, if the blower switch is on, and the A/C switch is on, this purple wire goes low (below 3V). When this wire goes low, it's telling the ECU that you want the A/C to come on. The ECU then turns on the A/C relay, by putting a low voltage on the A/C out (yellow/black) wire.

With all that in mind, what we're doing, is bypassing the ECU's control of the A/C. The instructions have you cut the yellow/black A/C out wire, and splice the harness end of the cut wire to the A/C in wire. The ECU end of the yellow/black A/C out wire is left open.

One downside to this bypass will be that the ECU can no longer turn the A/C compressor off when you get on the gas, and it will also leave it on while cranking the engine. This is from looking at the electrical info in the Mazda manual, though I haven't verified it yet on the car.

What I've noticed so far, is that the A/C works fine with the mod, however, the PFC doesn't seem to know that the A/C is on. For all I know, this may be why they did the mod in the first place. When the car is warm, and idling normally at about 750 rpm, if I turn on the A/C with a fan speed of 1, and no other electrical load, the idle drops to about 500 and struggles when the compressor is on. If I turn the fan up to 3 or 4, or turn on the lights, the idle jumps up to about 900. If I'm not mistaken, the idle should jump up with just the A/C on, even if there isn't a high electrical load. It appears that the target idle speeds are 720- normal, 800- high electrical load, and 900- A/C on. I'm still investigating this.

Well, that certainly got long. Sorry if I got carried away.

Cheers,

books

iTrader: (8)

thanks for the respone and rationale...I have yet to install mine...bought it used with no instructions...I did notice others having a/c related problems...perhaps this is the fix

redrotorR1

Any update on the AC fix? I just installed my PFC using only the 4-wire diagram and, guess what, the AC doesn't work. Good thing it's cool outside now. Any other problems from re-routing the AC out wire other than the idle issue?

13brv3

I haven't heard anything else, and I also haven't messed with mine any further. I'm going to be hooking up the Datatlogit and WB in the next few days, so I'll probably play with it some more, though I don't know anything else that can be done about the A/C idle problem. I'll likely just end up turning up my normal idle a couple hundred RPM. For now, I run around with the parking lights on to add electrical load, but mostly for the lower fan speed. Of course I won't need to do that as soon as I get the Datalogit hooked up :-)

I'm curious, did you get a new PFC recently, or is this an older one? Did the wiring instruction sheet show the A/C bypass. I'm still wondering if this wasn't something that the folks at Rotary Performance added into the package as a correction to the normal Apex document.

Cheers,
Rusty

redrotorR1

Yeah, I bought one of the SR Motorsports specials ... brand new with pre-tuning. I'm not happy with the preset parameters, but they're conservative enough that I'm not hurting the car. I'm waiting on some other parts before I get the whole thing properly tuned.

The instruction sheet that I got with my PFC didn't have any install instructions at all. Screw up from SR? Dunno. It has all the literature up to the diagram(s), but nothing else. SO, I just followed the standard 4-wire procedure, documented here, for now ... guess I'll see what my tuner does to fix the AC problem. Maybe he has a different approach that will work.

redbase

The A/C works with my PFC with only the 4 wire cut. I did notice, quite immediately, when I turn on the A/C (no matter the fan speed) my idle jumps up to about 1000 rpm, then slowly drops to 750rpm...then repeats the process as long as I'm at idle. Go figure?!?

Fooboy

I just got a PFC directly from Japan. From a very rough translation of the instructions, you may wish to expand on the idle learning instuctions in you install guide.

Basically it says that you need to warm the car up to operating temperature (80 degrees C water temp - use handset to check, or wait till radiator fans come on with no fan mod) let the car idle for 5 mins (or more if it cannot settle down) under each of the 3 following conditions to let it idle learn properly.

1. No electrical load
2. Lights switched to parking light position (everything else off)
3. A/C on (everything else off)


I should be getting PFC installed and tuned in a couple of weeks. I'll let you know if this worked or not.