MK4 Golf 1.4 (1J1) wont start after timing belt replacement.

Hello! I have a MK4 Golf with the 1.4 miten petrol engine. We just did the timing belt and water pump on it. Now it wont start. It will crank as usual, but wont kick over. Spark is good, and so is the fuel. The timing is 100% correct, checked mutliple times. Compression also good on all cylinders. What could cause this? Does the knock sensor control timing/spark? Could it be bad? Please, any advice is good, since im not that good with engines.