Sounds like the same thing that happened to the 93 I bought. PO says he had a problem at a light and horsed it accross to a parking lot. It waS LOW ON FLUID, cracked torque converter. ANyway, after replacing the TC, it would act just like you're saying. It would move in reverse with a lot of objectiions. I think a clutch pack was toasted. Fluid was black, but didn't smell too bad. I drove it from Birmingham, Al to the house, about 300 miles without incident. Haven't torn it down yet, put my spare E4od in it.

 

If the forward clutch is bad all sensors/solenoids/electronics will work normally so the computer has no way of knowing about the clutch problem and so will not set a code or blink the OD light.
If you do need it rebuilt maybe drop the trans yourself and take it to a shop..
I hope I`m wrong about it (but don`t think so) so hang in there for other opinions.

 

Another dumb question:
Is the shift linkage actually moving the lever on the side of the trans correctly?

 

My understanding is that blinking the overdrive light was a feature added for the 1992 model year.

I agree this may be a welded clutch pack or at the very least some major internal issue. Reverse isn't really dependant on the computer working or not. You can pull every plug on the transmission and if its healthy, it WILL still drop into reverse (althought it may feel a little harsh).

 

Yep, any E4OD's before '92 had the overdrive switch on the dash, when they switched body styles at the end of '91 is when they moved it to the shifter. I don't think the error/blinking light happened until the shifter mounted OD button came along.