i just put in a fuel pump and it don't want to start it ran when i did it but it keep losing presser for fuel so i put a new one in and now it wont work i hooked every thing up right. what is going on with it now

my 1995 camaro doesn't want to start. I've gotten it checked out but they found nothing wrong with it. After it starts and I shut it off it doesn't want to start any more.

I've done took it to the auto shop and they can't figure out why the first piston is not registering to start the car. Sometimes it will work fine then after you turn it off it won't start. It is pissing me off and I've done tried to fix the problem but could not. At first I thought it was the timing chain so i replaced that but it still is doing the same thing.