From my understanding they don't reprogram your computer they just make a new chip for your specs and when you want to change it you have to have it done again. They typically reprogram the 0bdII computers. Other than buying a chip you could change your gears to match the tires.

88 S-10 Blazer 4.3l 2" body, torsion bar/shackle lift, 30" muds, custom front/rear bumpers, 4 KC daylighters, 3.73 Gears

 

Unless you have a digital readout for your speed, you can't reprogram ti.. its all mechincal.

Tim

88 blazer
Like A Rock

 

I was under the impression that JET or someone made a module that plugged into your electronic speedo and made the corrections based on the tire size and gears you input into the module?

Does anyone remember this? It's not part of the computer...

By the way, that 12 mpg you're getting is actually wrong. If you're speedo is off so is your odometer. You might be getting less due to tire changes, but not as bad as what you are seeing!

Hope that helps.

J.R. /wwwthreads_images/icons/cool.gif

http://members.nbci.com/desertride/index.htm

 

just thought of another way to change what your speedo tells you, find another speedo adapter for your transfer case that will match your actual speed. Probably a lot of trial and error involved.

88 S-10 Blazer 4.3l 2" body, torsion bar/shackle lift, 30" muds, custom front/rear bumpers, 4 KC daylighters, 3.73 Gears

 

There are companies that do speedo recalibration for you. They can determine what your average, um, offset (only word I could find to describe) in speed and put in an adjustment...

When I called my Chevy dealer here in San Diego they told me they don't do it there but refer people to a calibration place nearby.

Might want to see if the dealer has the same deal for you.

Hope that helps.

J.R. /wwwthreads_images/icons/cool.gif

http://members.nbci.com/desertride/index.htm

 

I found another company that makes chips, fast chip http://www.fastchip.com/. They can custom make chip too.

Craig

'89 S-10 4.3L 31" Yoko M/Ts (For Sale!)
'99 S-10 2.2L 2WD 5 Speed Totally Stock

'88 Kawasaki Mojave

 

The '89 is going to be something mechanical that needs replaced. It is going to take a calculator and a trip to the dealer to get it fixed. Fastchip cannot take this into account, I have one of their chips.

Should be very inexpensive, but maybe mathematically intense to get the correct gear reading on your speedo. The dealer is where to go.

Nich Kenny
'89 K1500 350/700r4