fuel pressure is 10 psi like ed said, and that pressure is maintained by regulator behind injectors on fuel meter cover,check fuel pressure, there should be shrader valve on return line to attach gauge to,the delay in throttle plate movement sounds like worn governor activation gear, disassembly for inspection required to confirm condition-check fuel pressure 1st, also as truck is being cranked check tbi injector spray pattern with timing light, you should see a nice uniformed spray cone underneath injector, any excess dripping while cranking,running -bad regulator, dripping after shut off also caused by leaking injector or upper fuel meter gasket or cover, also check engine oil for excess fuel and change oil if oil is gas washed or engine damage will occur