Pontiac Repair: 2000 Pontiac Bonneville only starts when step on the accelerator, fuel pressure regulator, pontiac bonneville

Question
Hi, I have 2000 Pontiac Bonneville (over 120,000) that has its check engine light on and often I have to step on the accelerator to start the engine; my auto-start also often didn't work to start the car. Can someone tell me what is wrong with my car? The funny thing, few times the check engine light turned on when I hit a pot-hole or big bump (sometimes it was on for days) and then when I hit another pot-hole, it got turned off. I am planning to take my car to the garage soon but looking for advice first since I got bad experience with another garage that gave me wrong diagnostic and charged me so high.

Thank you for your help and advice.

Answer
Hi Julie:

well first off with out knowing whay the sersvice engine soon lamp is on It's really hard to say for sure what the issue here is. You can go to any of the big box auto parts stores and theye will scan for codes for free and tell you what the lamp is one for. I'm sure they are related the hard start and the lamp being on. A guess would be possably a bad throttle osition sensor or a leaking fuel pressure regulator. You could have a dirty throttle plate on this car and that cause a hard start but not turn the lamp on. There could be a loose connetion to one of the snesors and that's why when  you hit a bump it acts up. The other factor here is the milage. when you have as many as this car has that adds a whole nother element to the mix being that parts wear out with high milage.. Good luck :)