Pontiac Repair: 97 pontiac grand prix gt, fuel pressure regulator, upper intake manifold

Question
i have a 97 pontiac grand prix gt v6 3800 3.8l.
it drove fine all day then pulled in front of store and it started sputtering and bucking then died started back for 10 seconds and died and wont start.scanned trouble code p0300 (random,multiple cylinder misfire) was wondering what you thought it was? also when i turn the ignition off there is a clicking noise coming from around the throttle cable area.thanks for advise....

Answer
Hi Bill:

well a p0300 is a random misfire. On this engine it could be a lot of things. If it has a lot of miles on it I would suspect possably an upper intake manifold that is starting to leak coolant into the engine and making it misfire. If it was wet/damp out you could have plug wires that are starting to arch and leak voltage. You could have a fuel pressure regulator that is leaking gas into the vacuum line for it causing the misfire. As for the clicking noise Is it under the hood? If it's near the throttle cable it could be the idle control valve starting to go bad. More than likely would not cause a misfire if that were going bad it would cause an erratic idle a low idle,fast idle or stall at a stop.