I have a 74 FJ40 that wont run and if I can get it to run it idles really rough and wont let me accelerate to higher rpms without dying or backfiring. It is acting like it jumped time but is that even possible with timing gears? I can turn the crank a significant amount before the rotor in the distributor moves. It has lots of blowby and the lowest cylinder is 90psi. The carb idle screw rpm adjustment is all the way in just to keep it running if it does run. Its an autolite carb that has been gone through. Any ideas of what this could be?