1996 z28 fuel pressure drops after turning key, need to turn over usually 3 tries then runs fine, with a gauge on it after you turn the key on the pressure bleeds of quickly, pretty much stock car with headers and cold air kit. I replaced the regulator and re did o rings on injectors, not sure if injectors are leaking but think it may be the check valve in the fuel pump. car runs fine after starting just hate cranking it like that. and body have any suggestions on what to check to be sure. thank you ahead of time this is a great site and is always helpful, Allen

 

Did you replace the regulator with a stock one or aftermarket one. The aeromotive ones for LT1's wont hold pressure after the pump shuts off.

 

If you are having problems with your fuel system not holding pressure, then start the engine right at the end of the prime and it should start fine. If the pump can't presurize the system in that time, then you got a problem with pump or injectors, and starting will be more of a chore. Put your gauge on there and see if it reaches pressure before the end of the prime (before it bleeds off). If it does, then the car should start. If it doesn't, then maybe the prime doesn't really squirt any fuel through the injectors. You can pull the whole rail off and see what hapens when you turn on the key - whether they squirt or leak - at least look at that (be careful doing it)

There's a million posts on this type of problem if you look for them.

 

My car was doing the same thing...had to turn the key to the off position, then back on, then back off, then back on to start it. Turned out it was the first sign of a fuel pump going bad. Replaced the fuel pump and havent had an issue since.