Toyota Repair Problems? Ask a Mechanic for Answers ASAP
Considering a mechanic has checked the pressure and is telling you it drops off intermittqntly then I would lean more toward a fuel delivery interuption as the cause of missing or jerking. Make sure to check the crankshaft position sensor. I have seen a bad sensor cause this, also seen a slight water pump leak onto the Crank sensor cause this. If that is all good then with the pressure dropping intermittantly, I'd look to the fuel pump as the culprit.