1999 Pontiac Sunfire PO200 & PO300 codes

1999 PONTIAC SUNFIRE
160,000 MILES
Avatar
FREMONT
  • MEMBER
  • 8 POSTS
looked at almost everything that relates to these codes and i can't find anything wrong but i got a bad miss. what is the chance i got a bad PCM? GOOD wires,plugs, coils, ICM, New crank sensor, Cam Senor ? did unplug and did get code , so i believe it is good? Injectors are good, i did a noid check on all 4 and that looked good. high speed runs good, low speeds and idle a real bad miss?
Jul 13, 2013 at 8:36 PM
Advertisement
Avatar
JACOBANDNICKOLAS
  • CERTIFIED EXPERT
  • 110,175 POSTS
Are you able to narrow it down to which cylinder is missing?
Jul 13, 2013 at 9:01 PM
Avatar
FREMONT
  • MEMBER
  • 8 POSTS
no i am not able to, it is so random. the spark plugs #3 & #4 were blackened(rich) #3 was more then #4. #1 & #2 looked good.i also hooked up my test light to see witch cylinder is missing and they all are. the car starts up with no problem. i tried a leak down by pulling sprk plug wires and it so hard to see a difference? i thought a about a compression test? the car has been running fine,so something went out just like that?
Jul 14, 2013 at 12:01 PM
Advertisement
Avatar
FREMONT
  • MEMBER
  • 8 POSTS
One other thing. I need to make up a fitting so i can check the fuel preasure. Do know if they sell that fitting/tool to hook up my fuel gauge tester? i will look on line for one. this is one thing i havent checked. i can hear it run when i turn the key i just don't know the PSI?
Jul 14, 2013 at 12:06 PM
Avatar
JACOBANDNICKOLAS
  • CERTIFIED EXPERT
  • 110,175 POSTS
I'm not sure what type you have, but you should be able to find an adapter.
Jul 14, 2013 at 8:16 PM
Avatar
FREMONT
  • MEMBER
  • 8 POSTS
Fuel PSI/regulator is good. So what do you think?
Jul 15, 2013 at 10:21 AM
Avatar
JACOBANDNICKOLAS
  • CERTIFIED EXPERT
  • 110,175 POSTS
The ignition has new parts, the fuel pressure is correct and we have a misfire. Have you checked engine compression?
Jul 15, 2013 at 8:39 PM