Trim/Year: LX 2002
Engine: F23
Trans: Manual
Mileage: 136k
Symptoms:
- no check engine light during idle or light load
- light sputtering from exhaust
- noticeable hesitation under load between 1-2k rpm
- under load the check engine light will illuminate and blink resulting in a P1399 (random misfire), cyl 1
First level troubleshooting:
- Examined original plugs, no traces of burnt plugs or oil saturation
- Replaced spark plugs with NGK
- disconnected Alternator (green plug)
No noticeable improvement
Second level troubleshooting:
- while running at idle, disconnected spark plug
+ Cyl 4, when disconnected, spark seen, engine performance drops
+ Cyl 3, when disconnected, spark seen, engine performance drops
+ Cyl 2, when disconnected, spark seen, engine performance drops
+ Cyl 1, when disconnected, spark seen, engine performance drops
General maintenance done regularly and fairly on schedule (within 5-10k miles of recommendation). When I bought the car at 82k I replaced the spark plug wires with bosch platinum, plugs with NGK and distro cap with AutoZone house brand.
BTW, I've read a number of posts here and a few other sites so thanks for all the historical data. Nothing seems to directly point to a solution so it must not be a common issue. Most posts resulting in the following actions:
- replace distro
- replace rotor (rare)
- pressure test, resulting in bad cyl or exhaust valve
Other notes: Fuel injector cleaner (stp) was ran over the past 2-3 tanks prior to this occurring, also over the past 1-2 months I've driven 2k+ miles mostly highway, speeding of course.
I have access to Android Torque so any data that you want I can pull from the logs if needed. I can also post videos if that helps, I have a couple hunches but overall I'm at a loss and I don't want to walk each small fix if there is something that I'm completely missing before I take this thing in.
Thanks in advance 6ga.
Engine: F23
Trans: Manual
Mileage: 136k
Symptoms:
- no check engine light during idle or light load
- light sputtering from exhaust
- noticeable hesitation under load between 1-2k rpm
- under load the check engine light will illuminate and blink resulting in a P1399 (random misfire), cyl 1
First level troubleshooting:
- Examined original plugs, no traces of burnt plugs or oil saturation
- Replaced spark plugs with NGK
- disconnected Alternator (green plug)
No noticeable improvement
Second level troubleshooting:
- while running at idle, disconnected spark plug
+ Cyl 4, when disconnected, spark seen, engine performance drops
+ Cyl 3, when disconnected, spark seen, engine performance drops
+ Cyl 2, when disconnected, spark seen, engine performance drops
+ Cyl 1, when disconnected, spark seen, engine performance drops
General maintenance done regularly and fairly on schedule (within 5-10k miles of recommendation). When I bought the car at 82k I replaced the spark plug wires with bosch platinum, plugs with NGK and distro cap with AutoZone house brand.
BTW, I've read a number of posts here and a few other sites so thanks for all the historical data. Nothing seems to directly point to a solution so it must not be a common issue. Most posts resulting in the following actions:
- replace distro
- replace rotor (rare)
- pressure test, resulting in bad cyl or exhaust valve
Other notes: Fuel injector cleaner (stp) was ran over the past 2-3 tanks prior to this occurring, also over the past 1-2 months I've driven 2k+ miles mostly highway, speeding of course.
I have access to Android Torque so any data that you want I can pull from the logs if needed. I can also post videos if that helps, I have a couple hunches but overall I'm at a loss and I don't want to walk each small fix if there is something that I'm completely missing before I take this thing in.
Thanks in advance 6ga.
