Aftermarket trip computer for OBD1??

[Vettepilot]

Hi,

Restoring a 1994 GMC K1500. I would love to add a trip computer that shows mpg, etc. I know these were available from the factory, because my 1987 Corvette has one.

Does anyone know of any aftermarket - add on trip computers that work on older cars with OBD1 systems??

Thanks!
Vettepilot

[Blue Bowtie]

The '93/94 Y-body or D-body trip computer might be supported by the PCM in the '94 C/K, but would require programming and a bit of creative wiring and mounting to adapt to the truck. The Cadillac version could be a little easier than the Corvette version.

There might be some out there, but I don't recall ever seeing any aftermarket items like that for anything pre-OBDII, probably due to the programming and data link required to operate one.

[Vettepilot]

I know a little bit about computers, and a little bit about electronics, but not near enough to create what I want unfortunately.

Even with simple OBD1, we have fuel use information via the EFI. Combine that with the distance covered via the in place speedo electronics, a super basic computer to do some 2nd grade math and a driver for a digital display and voila, an OBD1 Trip Computer.

If only...

:~(

Thanks,
Vettepilot
PS: I bet someone well versed with Arduino could pull this off. I just have too many "must finish" projects to stop and learn Arduino, though it interests me.

[Blue Bowtie]

It's a reasonable assessment, but unfortunately the market for such a device is shrinking daily, and the time/cost of development might never get recovered.

AFAIK, the factory DIC systems would use already-existing ECM/PCM functions, including current cycle run time since start, RPM, load factor (LV8), injector pulse width, and VSS input to do the relatively simple math, along with some NVRAM to store between cumulative data resets.