missing/ breaking up

[aa1320]

87 gn, I replaced mass airflow / o2 sensor and has new plugs and wires after running fine for about a week now it his back fire and missing when it is under full throttle for more that a second or 2. it has never done this before and is only running about 15-16 boost mostly stock car. I was thinking it may be the coil pack? or something related to that? Any idea or info would be appreciated before I start tearing apart. It still runs fine under normal conditions and even above 1/2 throttle but if running hard for any period starts the missing break up issue? Thank you for any and all help

 

[slick6732]

could be weak coil pack! Know it sounds crazy but check vacum line running to wastegate, had similar problem and mine had a hole in it and was doing about the same thing under boost!!

 

[slick6732]

Also what plugs did you use?

 

[slick6732]

one more thought! You may check the maf hose for holes between the mass air sensor and the turbo inlet, may be letting unmetered air in..

 

[bosted86]

had same problem. i changed the module with ac delco unit and the car is a beast now.

 

[DONNIE BROOKS]

had same problem

turned out to be a cracked spark plug ,i changed every thing else first of course ,good luck with it

 

[aa1320]

thanks for all the help I am going to try to get to look into it this weekend

 

[turbojd]

Check the coilpack