ScanGauge?
 

My '91 Festiva was built prior to OBD I and OBD II, does this mean I can't use any sort of ScanGauge? Is a vacuum gauge my only tool to use?

You could pick up a superMID from Matt, which is what I use on my crx. You'll prolly have inaccurate instantaneous but you ought to be able to dial in the long term fuel trim. I don't really mind it being inaccurate, relative performance is all that really matters.

What year is your CRX?

91, originally pre-OBD (OBD0 as we call it), but now it's OBD1.

What is the significance of "SVOboy"? Straight vegetable oil?

I ask because I own a Comp Prep SVO Mustang...........

Veggie Oil, my main man.

Is your CRX a diesel ? lol

Nah, I just carried the name over from when I was into dubs three years ago.

As SVOBoy mentioned, a SuperMID should work.

I see no reason why it can't be accurately calibrated. I'm going to be sending off for a batch soon. I'll make an annoucement when they are available.

If by chance your have a carburator, I would recommend looking for a Zemco Computer on ebay.

SuperMid
 

Matt,

I was reading a thread about the SuperMid. It looks like it needs two connections? One to an injector and one to a speed sensor? The injector is no problem for me, but I believe a Festiva speedo uses a cable to drive it and it doesn't have cruise control. So I'm not sure a SuperMid would work for me? Any other alternatives besides converting over to the electronics from an Aspire and then run a ScanGauge (to much work for me)?

Kraig: Can you give us a better idea of what the Festiva has. Is it fuel injected or carburated? If it's fuel injected, is it MPFI or something else.

I'm fairly sure it'd be some Fordy/Mazday version of MPFI.

Yoshi told me that he found a magnetic alternative for the supermid. It seems like it would work, but it woudl cost a little extra to get it working (Yoshi needs to add an extra sensor to the SuperMID to get it to function properly).

Mid 80's chrysler products had a device that hung on top of the transmission, where the speedometer cable comes out. It was basically an adapter that received the cable and then had a cable replacement to go into the speedometer. The sensor had 2 wires off of it, so that it could be used for cruise control. I wonder if something like that might work on the Festiva?

Mpfi
 

The Festiva does have MPFI with a vane air meter etc (not speed density). I'm sure it is Mazda derived as is the rest of the drivetrain. The body and final assembly was by KIA (made in Korea sticker on 'em). The motor is a 1.3 liter four banger with 63 hp and like 58 ft lbs of torque.

Hello from Japan,

Yes. I got some sample speed sensors as a picture below.
It has a lead switch and produces four ON-OFF signals per revolution which is the same number of digital SPD signal required for the SuperMID M-1.
We need some circuit to clean up noises and chattering of the lead switch.
Anyway, it should work on the Festiva.

Yoshi

https://image.www.rakuten.co.jp/iida/img1022181952.gif