1997 chevy blazer runs good until about 50mph and then doesn't want to accelerate.

I am all mixed up P0700 on ford mondeo
for blazer it's a code saying you have a transmission code set

Have you checked fuel pressure under various conditions ?

i would start by investigating the fuse box for a possible blown fuse.also double check the wiring connector is fully seated on the part you have replaced

SOUND LIKE A FUEL FILTER PROBLEM...

has anyone checked the front drive shaft u joints, play in the differentials? differentials would come and go as you accelerated and let off.

In my 1997 chevy S-10 The gauge dash lights wont turn on when I flip the switch but both turn signals come on solid instead?!!? please help

If there is no switch present then it is full time 4X4, it does not disengage, good for travel bad for fuel mileage.

It likely needs a fuel pump, hook up a fuel pressure gauge, it needs to be 11-13 psi

swng,
1) Is the service engine soon light ever on when engine is running?
2) Per your description I would look at the ECT sending unit. It sends coolant temperature information the the Engine Control Module for proper fuel delivery for cold engine start. It may have lost its calibration.
Let me know.
Regards,

I had that problem with my 96 blazer , than i smelled burning for a while ! It was my transmission!