Pontiac Repair: egine misses and injector problems, fuel pressure regulators, vacuum leak

Question
recently i have to do a top end rebuild. well close. lifters rods all the gaskets. anyway. i got the motor put back together after a week of work. now its missing. like timing. i think its a vacuum leak not. but my real question is why the injectors keep leaking. they wont leak for a while then they do...then they will stop again. i think it gas to do with the vacuum and the fuel regulator. what do you think. the car is a 96 grand prix with the M CODE 3.1

Answer
Hi chris:

You may have an issue with a vacuum leak these cars have a fule rail that is tricky to put back in. If you rolled an o-ring over on the tip of the injector where it presses into the intake manifold it will have a vacuum leak. If you had a hard time getting the fule rail out when you took it apart you may have damaged one of the o-rings on the top of the injectors where they press into the fule rail thus the fuel leak. The dealer sells a kit that hass all the upper and lower o-rings in it. I suggest you take it apart and replace ALL of the o-ring seals. The kit is pretty inexpensive like less that $30.00. The fuel pressure regulators as a rule fo not leak on these cars unless you distrubed them when you had the fule rail off. They sell a seal kit for that as well for where the regulator goes into the rail and where the line goes into the regulator. It's a different kit though.  Good luck