a few weeks ago my car was having missfires so i replaced the coils, wires, and plugs. it solved it for about a few days then it would have missfires again, it would always crack the spark plug... so i got the deep dish socket as told, replaced it... still having missfires and the plugs are still good. So i replaced the fuel injectors. I bought 39lb and tuned the pcm to work with the bigger inj. Now it is still having very bad misses and it is running very rich. It is random misses with a P0300 code. please help, i am at a total loss! thanks.

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2004 Black GTP Comp-G.... SOLD
NEW RIDE:
-99 Trans am
* midnight blue
*6sp manual
*t-top
* ls1 (305hp 350tq stock)
* B&M ripper short shifter
* hooker long tube headers (not installed yet)
* slp air lid
* corvette Z06 rims 17"/18" staggered

What scanner are you using to diagnose the problem? Which cylinders are misfiring exactly? Did you double check your fuel pressure & compression in each cylinder?

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Thanks
Scott McKinney
http://www.motortopia.com/cars/16218" onclick="window.open(this.href);return false;

i am using an aeroforce scan gauge, all the cyl are missing, i didnt check the fuel pressure and cyl compression.... will do that. my aeroforce can tell me fuel press but i might have to go to someone for the compression.

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2004 Black GTP Comp-G.... SOLD
NEW RIDE:
-99 Trans am
* midnight blue
*6sp manual
*t-top
* ls1 (305hp 350tq stock)
* B&M ripper short shifter
* hooker long tube headers (not installed yet)
* slp air lid
* corvette Z06 rims 17"/18" staggered

my car is the same thing... but i still didnt change anything

can you feel the misfiring or is it just reading it?>

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05 Bonne GXP, click for cardomain


somethings just cant be replaced ... good times...

i can deff. feel it! the car shakes and you can even hear it missing.

_________________
2004 Black GTP Comp-G.... SOLD
NEW RIDE:
-99 Trans am
* midnight blue
*6sp manual
*t-top
* ls1 (305hp 350tq stock)
* B&M ripper short shifter
* hooker long tube headers (not installed yet)
* slp air lid
* corvette Z06 rims 17"/18" staggered

Definitely check fuel pressure and cylinder compression, then go from there. Also a common issue with misfiring is a defective ignition control module on these vehicles, overlooked a lot too. The ICM is under the coil packs, give it a test too. Let me know what you find out.

_________________
Thanks
Scott McKinney
http://www.motortopia.com/cars/16218" onclick="window.open(this.href);return false;