1989 f150 302ci 5 speed manual. Loose power when motor gets under a load ( any slight incline). I would be driving in overdrive hit a inclince and start loosing speed drop down to 4th still loosing speed drop down to 3rd and so on. Rpms dont increase stays very steady around 1300 (if gauge is correct). push in clutch and she'll rev when I hit the gas. What do ya'll think it could be I have thought of the firing order being wrong and possible a clogged cat or collapsed muffler, will look in to those two tomorrow. Any other ideas of what I should look into?
Thanks

 

If the firing order were wrong, it would be running rough, if even running at all, and probably knocking like crazy.

 

figured out the problem cruise control cable was sticking. Did not know the pedal moved that much haha. Now to a few other small things

 

Im sure it needs a tune up was told by PO that it just had one but the cable used to go from coil to distributor is in wrong place and just by driving it feels like it has a little lag. probly from a few vaccaum leaks and tune up done wrong ( timing probly needs a little adjusting too). thanks