Pontiac Repair: 1999 Bonneville, fuel pressure regulator, gas milage

Question
Hi,,I have a 99 Bonneville and am having some problems,1st the car idels rough,,slow take off with rough running and getting poor gas milage. I have replaced spark plugs & wires,,,injectors,,and 1 of 3 coil packs, The check engine lite is on blinking,,can you help me,,also,can you tell me where i can find the vaccum line diagram so i can check those also.  Thank you so much for your help, Geoff

Answer
Hey Geoffrey:

the lamp on blinking is because it's misfiring bad enough to cause catilitic converter failure which is not good. Now what is the engine missing that it's misfiring?? Is it spark or fuel My guess is spark that's why you replaced the coil and wires. It may have a plug that carbon tracked on the outside and it's causing the misfire. If not then maybe a plugged injector?? The diaphram your looking for is the fuel pressure regulator it's loacted on the fuel rail. Hope that helps. Good luck :}