Finally registered
 

Hello all,
My name is Jessie, I got into hypermiling after my lead foot and turbo started costing too much, thanks to my 1990 ford probe gt (turbo 4 cyl) I discovered an instant mpg gauge as well as average mpg gauge. eventually it became a game to me to see just how much mpg I could pull out of an all stock 1990 Probe GT. Much to my surprise my best city mpg is 42 and highway is 51. I get yelled at alot for my granny like take offs from lights and forever long accelerations around town, but I just keep watching that digital gauge go up numerically haha.

However, now that the Probe has spoiled me with a DRO (digital read out) style mpg gauge, I have grown quite accustom to it and really dislike my other cars for not having one. I have since discovered the MPGuino and been hooked ever since and am currently attempting to build one myself. (I am mechanically inclined not software inclined though) when reading codes I get lost very easily and feel like a caveman with a craftsman wrench!
I am so happy to be part of this community and finally registered instead of lurking around like I have been for about a year or so now.

all the best
Jessie

Welcome to the site Jessie.

Welcome, I think that you would love a vacuum gauge because of the instant feedback it gives you.

I already have one of those but it's not the same as a read out

What other vehicles do you have, that you can't hook up a Scangauge or Ultragauge? Or are you just that determined to roll your own?

I know the older vehicles don't use OBDII, so those over the counter solutions don't work. They have to have the standardized protocols to interface with the cars; MPGuino and possibly other solutions will allow you to talk to the engine computer even if it's using a different protocol.

Well all of my fun projects/toys are pre-95
1992 Plymouth Laser
1994 Mazda RX-7
1980 Mazda GLC (f2t engine swap underway)
1990 Toyota pickup (355ci swap)
1980 Toyota pickup stock

I am not aware of any other computer based system for OBD1 cars besides the MPGuino and oem manufacturer systems.

*on a side note is there anyway to wire an OBD2 port into the harness of an OBD1 car to get the values needed for say a "scan gauge" OBD2 tool to work with the prehistoric OBD1?

I don't believe so because the obd2 standards required are built into the computer.
If the computer is the same, between obd1 and obd2 cars for that model than I would guess the wires for the plug would be there. I'm not sure I never really looked into it.

Welcome. I've had an MPGuino in my car for years and I love the instant feedback. It has really helped me hone my driving technique. I bought one preassembled though. I wouldn't feel comfortable building my own, especially the software side of things.

Unless you added EFI to it, I know that 1980 Toyota PU is only going to be measured tank-to-tank.

I have looked into analog fuel computers. They're spendy and you usually have to add a flow meter to them for instantaneous feedback. For that I just recommend a vacuum gauge.

I don't think the OBD1 protocols are the same as the OBDII, so even constructing a wiring adapter still wouldn't serve your purposes to hooking anything up to it, not anything that was expecting to read OBDII. In that instance I reckon the customizability of the MPGuino is your friend, you can make it talk to pretty much anything with an engine computer.

The 80 Toyota pickup is planned to get a 2jz (supra) engine in it down the road at which point would be fuel injected. (sorry didn't give that info prior)

as far as the OBD2 port wired to the OBD1 harness, after reading your post I believe you're absolutely correct. the system is speaking English while the OBD2 scan gauge is trying to read German (figuratively)

So back to the drawing board with the MPGuino. I finished my MPGuino and now time for install and testing.