86-95 Trucks & 4Runners 2nd/3rd gen pickups, and 1st/2nd gen 4Runners with IFS

Monitor OBD-1 Data stream

Old 07-12-2018, 07:52 PM
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Monitor OBD-1 Data stream

The '92-95 4runners/pickups generate an early data stream through the VF1 port when TE2 is grounded. LOTS of interesting stuff, like the injector open time, and so on. It's not standard RS232 -- close, but not close enough to read with a UART. User RJR wrote a program to read these codes (by "bit-banging"), but it requires a laptop with a parallel port (yes, the '90s are calling to get it back!) and some electronic assembly. Whew!

Enter Francois. He developed a box that plugs directly into the Diagnostic port, and connects to your Android phone via BlueTooth. Everything you can want and more! Works very well.

Now, he's released a new and improved version (making the one I've got obsolete. Darn!) For the money, you can't beat it.

He used to offer a unit with open wiring, that you could splice into the wiring at the ECU. Splice??! Not for the faint of heart, so he now only offers the direct-plug-in version. Easier to use, but then the box is left under the hood, where it is pretty hot. Mine worked fine under the hood, but I would take it out rather than leave it permanently installed. I worried about the heat.

Don't get TOO excited about accessing all this data; it comes out in a 90's era format, which means it only refreshes about once every 1.2 seconds. But with that in mind, it's irreplaceable.

If you're the kinda girl who would plumb in a fuel pressure gauge (and have a 92+ vehicle -- sorry Rad4runner), then this is the box for you.

I'm just a satisfied customer; I don't get any swag for this. But wait, Francois, are you listening?
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Old 07-12-2018, 09:23 PM
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That device looks pretty sweet!

Even though the refresh rate of early diagnostic systems are slow by today's standards, having any data showing you what the computer is seeing opens up a whole new world when diagnosing engine-related problems. The data could give you some insight as to why the Engine Control Unit is setting a particular code. It wasn't until recently that I knew you could extract more than just codes from the Engine Control Unit on these trucks.

Do you know what type of data (if any) you could get from 1987-1991 EFI system? I am sure it is more limited than later Engine Control Units. Toyota started using the Diagnostic Box in 1987 to replace all of the separate connectors in earlier EFI versions.

^^ This question is mostly for curiosity. It won't do much good for my 22R. I am the diagnostic port for my truck!

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