My 1996 3.4 liter (manual) T-100 loses power in all gears at 3000 rpm and unitl yesterday has been getting harder to start. If I put the truck in neutral and let the RPMs drop below 1000 I can re-engage the gears and continue on as long as I stay below 3000 rpm. I changed the fuel filter which made no difference, I began thinking it was then either the fuel pressure regulator or the fuel pump but my local mechanic checked out my fuel pressure system and didn't see any issues. I lost total power on the highway yesterday and couldn't re-start, had to be towed to Toyota service shop. Any ideas on what the issue may be?