16vhelp urgent!

[srboy]

i finaly have a 16v for my nova, at present it is still in the astra gte. the prob is that when i got it home it started first time and was running for 20mins then i turned it off. then i took out the plugs to check them then put then back in . then later on in the day i went to turn it over and it wont start!. it turns over fine but just wont fire up. there is a definit spark and petrol is going in so it shuld start! y wont it!. also when i click the ignition in i cant hear the fuel pump hum like on my gte nova should it hum or not? it isnt an in tank pump! i wouldnt mind if it never started but like i said it did first time till i took the plugs out!
any help apreciated

[CP]

Just a thought - since the only change you made was the plugs, have u reconnected everything right and all connections good? Soz if u have checked this but we've all been caught out and its easy to overlook basic details like is there enuff fuel etc etc

[srboy]

yes m8 ive done it before on my gte u think y is it running shite!!! nah the fireing order is correct and fuel is present i think its an immobiliser fault