Upshift indicator after gear change
I have a 1988 coupe with an automatic trans. It was originally equipped with 2.59 rear-end gears. After 15 years of tender-loving care and some minor mods, I'm happy to have finally swapped my gears.
I just replaced them with 3.07s and am pleased with the combination of increased performance, minor increase in engine RPM at cruising speed, and very slight decrease in fuel economy. This would be considered by some as a very mild change -- but that's just what I want.
With the 2.59's, I would tach appx. 1,400 RPM at 65 MPH.
After the change to 3.07's, I tach now at 1,900 RPM at 65 MPH.
Now after half a minute, the "upshift" indicator illuminates (and stays illuminated) after sustaining cruising speed (65 MPH).
The car does make it to overdrive and I was expecting a slight RPM increase. But is the upshift indicator supposed to stay on? Will it be necessary to replace the chip with an after-market chip to stop the upshift lamp from staying on?
Aside from the unwanted upshift lamp, by replacing the rear-end gears, is my ECM now getting "wrong" information and under-performing as a result of this gear change?
Any advice will be appreciated.
Thanks,
Norman
Last edited by NormanNoble; Nov 16, 2010 at 01:06 AM.
The swap to 3.07 gears was the last thing I'll be doing to my '88 so I'm ready to revisit another custom EPROM swap. I'm keeping my fingers crossed that I'll find a reputable programmer for this.
Some friends have said not to waste my money on another "custom" chip through the mail and say that the only worthwhile chip swap is following a dyno tune. I'm sure the dyno tune would be optimal but my mods are modest -- mostly street legal bolt-on and I wonder if I would still benefit from another mail order "custom" chip (any leads would be appreciated!)
Thanks again,
Norman
San Mateo, CA











