My completely stock '99 LX (D16Y7 with automatic) is suddenly having the following problems I would appreciate any input on:

1.) The speedometer works but it always displays between 10 to 20 mph higher than actual speed (as verified by GPS). From a start the needle jumps up to about 20 mph and is offset from there on up. Sometimes when I floor it at highway speeds---the speedometer jumps up to say 120 mph and then drops back down to 15 or 20 mph too fast.

2.)The car shifts kind of hard and then it feels like it slips a little bit. I'm not sure if the transmission is suddenly shifting hard and slipping or if maybe the torque converted is locked up during the shift and then unlocking a little afterwards causing the slight slip.

3.) When it is warmer than 70 or so, the car dies. I get no CEL or anything. On cold days, everything is good. Also, it seems to only do this when I first start the car or at stop lights---so when the engine is idling with the car in gear. If I put it in neutral at every light, it makes it.

I thought I read the VSS controls speedometer readings, torque converter lockup timing, and fuel injection duration. I was thinking about replacing it. Since I'm at about 100k miles, my friend changed belts, fluids, filters, cap and rotor, plugs and wires, set ignition timing, and told me my fuel filter was dirty as sin. I also was thinking maybe my fuel pump was damaged by such a fouled up filter(yes I'm aware of the debate whether they die suddenly or slowly). Maybe that has something to do with the dying.

I'd appreciate any thoughts or help.

 

bump for any ideas