Izzy problems!

[crzdylan]

I have a 1.8l 1zzfe that has been rebuild because of the oil consumption problem. Right before it was rebuilt, it became extremely sluggish and was popping po300, po302, and po171 constantly. When the motor was torn down #2 cylinder had a burnt valve, rings were stuck, and carbon everywhere. All bearings were in spec, but they were still replaced. Pistons, rings, timing set, and plugs were replaced. I am still getting a sluggish acceleration, and popping codes po171, and po300. I have tested the injector resistance, seemed ok. Tested spark, seems ok. Tested the wiring harnesses, cleaned the maf, intake, and checked all of the vacuum lines. Not sure what to try next as its the first yota i've worked on.. any tips would be much appreciated.

[crzdylan]

Update. Today i cleaned the IAC and rechecked all of the vacuum lines. After i did that without change i started pulling connectors off while the car was running. Started with the IAC, idle smothed out but jumped from 750-800 to 1k, also popped code po505. Next i checked the TPS, the car would idle fine, but if i turned the accel, it was fairly rough through the rpm range. I also disconnected all of the injectors (one at a time), each making the car run obviously worse than before. I also disconnected the coil packs (one at a time) having the same effect as pulling an injector wire. I havent seen any po171 codes in the last day or so. I am thinking that SeaFoam cleared that problem up, but im still getting a po300 (random misfire) and the engine still has the same sluggishness. Last night, just because i feel like im beating my head against a wall, i pulled the valve cover, lined up all the timing and checked that everything was correct (it was correct as per the downloadable Toyota repair manual). Anyone see anything that im missing? Connections seem good, all the harnesses seem good, injectors, coils and sensors seem fine. Im at a complete loss as to what to do next.

[crzdylan]

Update, So after testing, checking lines, checking everything over and over i decided just to swap out the injectors. It wasn't cheap but with 180k original miles, and no documentation of maintenance when we bought the car i figured this would be something that wouldn't hurt to change anyways and would help narrow down the list of suspects. All four of them tested fine but as soon as i swapped them OMG! This car came to life like never before! I would be willing to bet that they in fact were original and the previous owner did not take care of his fuel system. I think that i will still try to replace the coil packs soon, as well as the O2 sensors. My reasoning is that since i don't know what has been maintained on this vehicle and to prevent future breakdowns, poor mileage, etc. These are bound to be standing in line to fail.