dustinb

I wrote this a couple of years ago and figured I'd post it up.

The diagram above is a picture of the connectors on your ECU wiring harness. The ones shaded in pink are unused for installation on the miata. It really is fairly straight forward. You will not be using most of the wires on the F/IC. It would be good to get some heat shrink and cap all the ends of the wires that you won't be using. There are two ways to wire the F/IC. Tap and Intercept. Tap is just "tapping into the wire". Intercepting involves cutting the wire, and joining the ends of those wires to two wires on the f/ic (in and out). The intercept tecnique is quite logical. The wires are labeled with a O or and I in them. The input always comes from the sensors themselves (which are in the motor), so therefore the INPUT wires are always on the engine side of the wiring, and the OUTPUT wires go to the ECU (the F/IC is OUTPUTING the signal to the ECU). This also helps you get familiar with the wires you will be using. Here is a break down of what sensor the connectors are, and what they hook into on the F/IC

1B - 12V Switch Power - Connects to wire labeled "IGN PWR" on F/IC - Installs in line (Tap)

2A - Ground - Connects to wire labeled "PWR GND" on F/IC (Tap)

2B - Ground - Connects to 2nd wire labeled "PWR GND" on F/IC. There are two PWR GND cables on F/IC (Tap)

2C - Sensor Ground - Connects to wire labeleld "SIG GND" on F/IC. (Tap)

2E - Crank Angle - Connects to wires labeled "CRK HALI+, and CRK HALO+" on F/IC. (intercept) The CRK HALO wire wires into the ECU side of the cut wire, and the CRK HALI wire wires into the Sensor side (going to engine) of the wire. The Crank angle sensor is a HALL type in the miata.

2G - Cam Angle - Connects to wires labeled "CAM1 HALI+, and CAM1 HALO+" on F/IC (intercept). The CAM1 HALO wire wires into the ECU side of the cut wire, and the CAM1 HALi wire wires in the Sensor side (going to engine) of the wire. The Cam angle sensor is actually deduced internally in the crank angle sensor. It's sort of a confusing setup.

2M - TPS Sensor - An interesting thing the TPS sensor. It was present on the Automatic 1.6L miata's, but not on the 5spd miata's of the same era. You can actually get the sensor from the automatic miata's and install them into your 5spd, and then run a wire to the F/IC. This wire connects to the "TPS +" wire on the F/IC (Tap).

2N - I actually left this out of the plug diagram above. This is the O2 signal wire. You can choose to wire this yourself, but really, the O2 sensor in 1.6L miata's is pretty useless. It's such a low voltage range that there really isn't much point to modifying the signal. IF you want to hook it up, you will probably need to install a resistor (see F/IC instructions), and it hooks up to the "O21 +" wire on the F/IC (tap).

2O - MAF - Connects to the wires labeled "MAF IN+ and MAF OUT+" on F/IC (intercept). The MAF OUT+ wire wires into the ECU side, and the MAF IN+ wires into the Engine side of the wire.

2U - Injectors 1 and 3 - Alright, in later years the Miata seperated the injectors on the ECU so they were controlled individually. However on our 1.6's, they are done in batches (1 and 3, 2 and 4). The F/IC on the other hand handles each injector individually. So after a bit of talking with AEM, they suggested that I connect the INJ 1 and INJ3 wires into this ECU wire. So this wire connects into the "INJ 1 OUT, INJ 1 IN, INJ 3 OUT, and INJ 3 IN" wires on the F/IC (intercept). The OUT wires connect to the ENGINE side of the wiring, and the IN wires connect to the ECU side of the wiring. This is different from all the other sensors becuase the ECU is sending the signal to the injectors, not the other way around like the other sensors in the car.

2V - Injectors 2 and 4 - See the 2U instructions. This is the same except you will connect the wire to the "INJ 2 OUT, INJ 2 IN, INJ 4 OUT, and INJ 4 IN" wires on the F/IC (intercept).

One tip that AEM suggests is to only wire in one sensor at a time, and then test the F/IC to make sure that sensor registers. I would suggest that you do the Injector wires last, and make sure you set the proper size of injectors you have in the F/IC software. Another tip that I suggest is to not do all the wiring in one sitting. The F/IC includes a little loop cable that plugs the wires into themselves, thereby bypassing the F/IC. This allows you to run the stock ECU when either all or some of the F/IC wires are connected to the ECU. Also, the F/IC is USB powered, so you can update it outside of the car by simply installed the lastest F/IC software, and then plugging it into your computer. Anyways, I hope this guide helps, and enjoy your F/IC!

Magnevik

Thanks! I'm trying to get a fic to work on a 94, 1.8. But as soon as I plug it in it runs rich on idle, and I don't know why though. Without it it works fine on idle. It must be something with the injectors that fic modifies, eventhough it shouldn't since there is no supercharging present.

dustinb

You have to make sure to set up the F/ic properly. You'll want to set the proper injector size, and then zero out the fuel chart.

Magnevik

Thanks for your reply!
I have installed the slave firmware z110 and the main firmware x300.
I have installed the software 3.04 and upgraded it to 3.05.
I have a Miata 1994 1,8, but used your wiring scheme because it looked exactly the same as the wiring on the originall workshopmanual for 94.
I connected the injectors as batch just as you described that AEM suggested.
But it runs very uneven when the fic is connected, but when I disconnect the AEM and put the bypasswireharness supplied with the fic it runs original and good.
I have put on a MP62 BRP S/C and I have dual throttlebodies that are syncronized, and as far as I can tell I have done the welding of the wires correctly.
I have followed your advice to leave out the O2-wire, and use the MAF and TPS wires.


I have some questions though:

1. The fic, does it engage even when the boostpressure is nonexisting, isn´t it suppose to just let the ECU- values go through unmanipulated?

2. I have tried putting in the values of the injectorsize by rightclicking in the fuelmap and set the sizes there. The thing is that I have the original injectors so I just put in the original size on both "old" and "new" injectorsize inputfields. There is however no differece in how the car runs. I´m suspecting that the injectorsize is only nescessary if you increase the sizes, not if you keep original, is that so?

3.The injectorsize I guesstimated to be 265cc, I found this info on this url: http://miataturbo.wikidot.com/fuel-injectors
...and it should be the tan ones, although I think that mine looks a bit browner.
My question is; it says 254cc at 3bar fuelpressure, but uderneath it says 265cc, I tried both sizes and put them in on the injectorsizechange I described above but no difference. What do you think I should consider to be the appropriate size and do you think it matters?

4. Is there any other input that I don´t know of where you can put the injectorsize other then the one I described?

I appreciate any info you can help me out with.

Regards
Magnus

dustinb

Ok lemme see what I can do. The f/ic begins working all the time. It uses its built in MAP sensor to run vacuum and boost. Make sure the vacuum line is not blocked in any way, and where have you taken the source for the vacuum line?

Once again, make sure you zero out the fuel table chart (if there are any values in there). It sounds like you have setup the injectors properly.

Magnevik

The fuelmap is zeroed out, as it is from a new installation of the fic software.
The vacuumhose is the hard plastic tube that followed along with the fic. It looked alright to me, no kinks on it what I could see.
I´m taking the vacuum from the intake plenum chamber, and that vacuum splits so it operates the bypassvalve on the compressor as well.
Is there a way other then trying to blow air through the hose to see if it lets air through?

Magnevik

Do you think that the injectors are sequential after all?
I might have been wrong I think.
Check this out:
http://static.summitracing.com/globa...vm-30-1710.pdf
It actually says that up until 93 it´s batch but after that it´s sequential.
What do you think of it?

Regards
Magnus

Magnevik

Hello dustinb! It was that the injectors were sequential. The contact Y=injector3 and Z=injector4.
Now I have another issue; the fic won't make a basemap in ignition when the pressure is measured in KPA, set in the system setup. However if I change that to PSIA then it creates a basemap. Must be a programming hick-up, right?

ForAllMankind

This is pretty useful, good work

dustinb

Hey sorry for taking so long to reply. I'm guessing that is just a programming hickup because it doesn't really matter. Glad you got it figured out!

Magnevik

No worries!
It seems to be a programing hickup, I got a reply from Henry at AEM and he said he had the same issue when his regional/language settings weren´t set to US-english.

Magnevik

No worries!
It seems to be a programing hickup, I got a reply from Henry at AEM and he said he had the same issue when his regional/language settings weren´t set to US-english.

Magnevik

Hi Forallmankind!

I´m glad you find it useful.

G. Jay

Thanks for sharing Dustinb, this is a big help.

A pending rules change for SCCA autocross will make piggy backs legal for STS Miatas like my 1.6. There is only a CAI and exhaust allowed for other engine mods.

I'm thinking that your wiring scheme while using the WOT switch in the TPS (the TPS from the auto is not allowed) would work out fine. We're not allowed to mod the harness so an extension will be used and spliced into.

What's weird is that while I only see a cam sensor on the car my manual shows two crank sensors and you label one as a cam sensor.

For my purposes I'll be using an overclocked ECU and only need to modify fuel and spark at WOT. I'm trying to figure out where to wire the WOT switch signal to. I expect to use the TPS line for that.

If possible I'd like to pick you brain on a couple items.

Can the spark and fuel can be modified based on the TPS as well as the AFM or is the TPS only used for transient fueling? If so I'd probably wire the WOT switch to the HALO signal and just use it as a switch.

If it can only retard the spark then I'll need to run 20-22 degrees of static advance I imagine. I'm concerned about cranking and starting with that much spark. Do you know whether it will retard crank spark?

Was there any issue with it correctly calculating the engine rpm?

Where and how did you mount the unit?

Does the AEM F/IC seem like a good solution for this limited application or would you suggest anything else?

Thanks.

Jay

dustinb

OK i'll try to pick through a few of these. There is definitely something weird with the "two" crank sensors on the miata. I remember having to do a bunch of thinking/research about this when I was wiring it up. It's something to do with the car having two crank sensors, but they are both fed into one or something...

The spark and fuel are only determined by the built in MAP sensor. It uses the kpa/psi on one axis of the chart, and RPM on the other axis.

I don't think there was an option to retard the crank spark. That's available on the full AEM EMS standalone, but I don't think it was an option on the f/ic

It had no problem reading the engine RPM. worked fine right away.

As for mounting, I made the wires long enough that I could mount the F/iC in the glove box.

For the price and the features, I would say the f/ic is the best piggy back solution.

dustinb

Oh right, here's the info about the CAM sensor:
2G - Cam Angle - HALL Type. The Cam angle sensor is actually deduced internally in the crank angle sensor. It's sort of a confusing setup.

G. Jay

Thanks for the response Dustin. I wouldn't be allowed to use the MAP sensor and would need a work-around or a different devise. This could be a problem. It sounds like the software is relatively limited.

Thanks again for the help.

dustinb

Yeah it def won't work for you then. Probably next best option is a greddy e-manage.

dustinb

If you have a 96-97 or a 01-05 Miata and you want to use the F/ic, Boomslang makes a custom plug and play harness.
http://www.boomslang.us/aemfic.htm

G. Jay

Dustin, using your recommendations plus a couple ad-libs I have the FIC-6 working well on my STS 1.6 Miata now. I used the WOT signal as a sort of binary TPS for fuel adjustment using the beta 3.06 version software. I'm getting really good lambda control now. I've got a roughed in spark curve and the improvement in low to midrange torque is quite noticable.

The only issue I've not solved yet is the long crank time. It starts reliably but it consistantly seems to take ~5 seconds of cranking time. Did you have any similar issue?