Car Starts, runs 5 sec and then dies

I just installed my new Walbro fuel pump from JD's Performance and new fuel filter. My car starts right up and runs for about 5 sec and then dies. If I start the car and touch the gas at all, it dies immediately. I can start the car with the gas pushed slightly and it will run at 1500 or whatever I have the pedal pushed to and die about 5 sec into it also. For the record, this is a car that I got that needed to be finished putting back together after it was painted throughout. I also do not have the o2 sensors plugged in nor the MAF sensor plugged in. Do these have to be plugged in for the car to idle????

I recently bypassed the two sensors located on the passenger side strut tower and the egr and have not yet programmed the computer for this.

If anyone has had this problem, what do you think mine could be?

1991 LX 5.0 5 speed

Ok thanks. That is what I thought but wanted to make sure. There was a mass air meter in the car but I took it off and inspected it and one of the resistors was broken unfortunately.