2003 misfire code
Thread Starter
Racer
Joined: Sep 2005
Posts: 359
Likes: 0
From: Shoemakersville Pa
2003 misfire code
So I finally got to take the 03 corvette for a ride a couple of weeks ago . Started running real rough check engine light started flashing. So I assumed it was because the car was sitting for so long maybe one or two of the injectors were gummed up, kept driving and the longer I drove it seemed to get better. Flashing light went away and everything seemed fine. Then this past weekend went out again ran fine at first then same thing but this time check engine light stayed on. Got home connected to analyzer code P0308 comes up #8 cylinder misfire. Pulled plug, looked wet smelled like gas so figured its electrical not fuel related.
Swapped the #8 coil pack with #6 coil pack to see if that was the issue. Now I get code P0300 which mean it could be almost anything.
Car has 31K miles never changed plugs or wires, shouldn't have to with that kind of mileage. Any suggestions?
Swapped the #8 coil pack with #6 coil pack to see if that was the issue. Now I get code P0300 which mean it could be almost anything.
Car has 31K miles never changed plugs or wires, shouldn't have to with that kind of mileage. Any suggestions?
Le Mans Master
Joined: Mar 2011
Posts: 6,835
Likes: 302
From: Columbia SC
Here is the 2003 FSM diagnostic for P0300. I can not find anything on P0308 in any C5 FSM, does not exist. I am guessing your analyzer showed a misfire as plug 8 in P030"8".
https://www.dropbox.com/s/nldstblnu7...stics.pdf?dl=0
Mr. Sam
https://www.dropbox.com/s/nldstblnu7...stics.pdf?dl=0
Mr. Sam
Le Mans Master
Joined: Aug 2005
Posts: 5,375
Likes: 328
From: CA.
St. Jude Donor '13-'14-'15
Common sense dictates that not only mileage tells when plugs should be replaced-- but also age---your plugs are 12 years old---the plugs are simply past their usable life---I would change ALL of them---Also at 12 years old I would change all the plug wires---Either the stock GM wiresor the GM performance parts 'red wires"---
Also GM has changed the recommended plug gap from .060 to now a .040 make sure to gap them like that--The best plug choice is the NGK TR5 pre gapped at .040
It is rare to have a bad coil
Also GM has changed the recommended plug gap from .060 to now a .040 make sure to gap them like that--The best plug choice is the NGK TR5 pre gapped at .040
It is rare to have a bad coil
Thread Starter
Racer
Joined: Sep 2005
Posts: 359
Likes: 0
From: Shoemakersville Pa
Common sense dictates that not only mileage tells when plugs should be replaced-- but also age---your plugs are 12 years old---the plugs are simply past their usable life---I would change ALL of them---Also at 12 years old I would change all the plug wires---Either the stock GM wiresor the GM performance parts 'red wires"---
Also GM has changed the recommended plug gap from .060 to now a .040 make sure to gap them like that--The best plug choice is the NGK TR5 pre gapped at .040
It is rare to have a bad coil
Also GM has changed the recommended plug gap from .060 to now a .040 make sure to gap them like that--The best plug choice is the NGK TR5 pre gapped at .040
It is rare to have a bad coil
