Hello everyone. I have a 2004 Buick Rainier 6 cylinder 4.2 liter AWD. After changing the spark plugs and oil I now have a crank but no start condition. I disconnected the negative side of the battery before changing the spark plugs, there for there are no codes set. It is getting spark at the plugs and there is fuel up to the regulator. When i spray a little fuel in the throttle body opening the vehicle will start. Could it be the fuel regulator that is not allowing fuel to pass into the fuel rail and if so how could changing the spark plugs and oil make that go out. i would gladly welcome any insight that anyone May have to my problem. Thank You.

What is the fuel pressure while you are attempting to start it?

*Fixed title of thread to reflect actual problem*

I finally found out what the problem was with my Buick. it turns out that I fried the computer somehow by disconnecting the negative side of the battery. That is the only thing I can come up with. Purchased a computer from the junkyard and programmed it. I also had to put a fuel pump on it.it'* crazy how all this went bad just by changing the spark plugs and oil. What a day. If anyone has any insight to how that could have happened I would love to hear it. Thank you

You changed the pump because you thought it was bad, but it ended up being the PCM instead?

I replace the PCM first. Then after trying to start it I came to the conclusion of the fuel pump. When I turned the key switch on, I could hear the pump priming up. It would start up at first and only stay running for a moment. I tested the fuel pump pressure and found it to be 10 lb at best. I purchased a new fuel pump, installed it and now it seems that all is well.

I would like to give a shout out and thank you to Mike for fixing the title of this thread and to CathedralCub for the heads up on the fuel pump. Thanks guys.

Thanks!

Glad you got it figured out!

I may have spoke too soon. I came out the next day and it'* doing the same thing sgain. Cranking but not starting. I have no idea what could be causing this.

Even though the fuel pump was replaced, I would verify correct fuel pressure with a gauge and spark by using an appropriate spark tester. I would not replace any parts until the tests are made.