Troubleshooting

have 1995 nissan king cab xe/se and put new fuel pump in and relay ok and it’s fuel injection and it wont start on it’s own, but when i put my hand over the air intake it starts and when i put my hand off it shuts off.

Did you put the new fuel pump in because of this problem or did the problem start after you put the fuel pump in?

the truck woulded start before and then tested the fuel pump no pressure and replaced the pump then had pressure then it woulded start.

There has to be a major vacuum leak somewhere on the engine. If you can get the engine to run when blocking off the throttle body, it means air is entering the engine somewhere else and is allowing the engine to run. When you uncover the throttle body there’s now too much air entering the engine leaning the fuel mixture out which causes the engine to stall.

Tester