Toyota Repair: intake valve stuck open, simpal, intake manafold

Question
i have not done a comprestion test yet i parked it went it a store when i came out started it and it was poping back up the intake manafold and had no power it has a hard time starting when hot before this happend cold start is good iam about to get it back running was just hpoeing for somthing simpal before i took it apart  o and it has shifting problem have to clear gear first before shift or shift slow at low rpms it idals ok pops in intake when i give gas

Answer
Take a compression reading before taking it apart so you know which cylinder is causing the problem, if all cylinders have the same compression and are all low then the timing belt may be the problem, if only one cylinder is low then it's that cylinder that has a leak.