97 5.4L-Misfire Under Load
#1
10-08-2010 | 08:22 AM
Thread Starter
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Junior Member
Joined: Feb 2005
Posts: 3
Likes: 0
From: Maryland
97 5.4L-Misfire Under Load
Ok,
I'm sure the consensus is going to be to replace the COPS but before I order them I want a final opinion from the experts. Our 97 Expedition now has 202,000 miles, original COPs, I've finally changed all of the plugs- yes the last 2 back plugs went 202k before I got up the nerve to change them out. They actually didn't look too horrible either. Anyhow, I replaced them and within a couple of weeks developed a hesitation when accelerating. This problem really seems just like a vacuum leak when the PCV boot failed. The idle is good on the car. I've checked the vacuum lines for leaks, replaced the PCV line for the second time so thats good- no other leaks found. Also, I was on a long day trip when this thing started acting up. The engine light came on after running for about 3 or so hours. A scan later produced a P301 code- cylinder 1 problem. I've since pulled the #1 COP and tested for spark- it still fires ok. I haven't checked the injector to see if that affects the operation, that's next. Any wisdom here is greatly appreciated!
I'm sure the consensus is going to be to replace the COPS but before I order them I want a final opinion from the experts. Our 97 Expedition now has 202,000 miles, original COPs, I've finally changed all of the plugs- yes the last 2 back plugs went 202k before I got up the nerve to change them out. They actually didn't look too horrible either. Anyhow, I replaced them and within a couple of weeks developed a hesitation when accelerating. This problem really seems just like a vacuum leak when the PCV boot failed. The idle is good on the car. I've checked the vacuum lines for leaks, replaced the PCV line for the second time so thats good- no other leaks found. Also, I was on a long day trip when this thing started acting up. The engine light came on after running for about 3 or so hours. A scan later produced a P301 code- cylinder 1 problem. I've since pulled the #1 COP and tested for spark- it still fires ok. I haven't checked the injector to see if that affects the operation, that's next. Any wisdom here is greatly appreciated!
#2
10-08-2010 | 08:26 AM
Senior Member
Joined: Feb 2004
Posts: 10,390
Likes: 9
Ok,
I'm sure the consensus is going to be to replace the COPS but before I order them I want a final opinion from the experts. Our 97 Expedition now has 202,000 miles, original COPs, I've finally changed all of the plugs- yes the last 2 back plugs went 202k before I got up the nerve to change them out. They actually didn't look too horrible either. Anyhow, I replaced them and within a couple of weeks developed a hesitation when accelerating. This problem really seems just like a vacuum leak when the PCV boot failed. The idle is good on the car. I've checked the vacuum lines for leaks, replaced the PCV line for the second time so thats good- no other leaks found. Also, I was on a long day trip when this thing started acting up. The engine light came on after running for about 3 or so hours. A scan later produced a P301 code- cylinder 1 problem. I've since pulled the #1 COP and tested for spark- it still fires ok. I haven't checked the injector to see if that affects the operation, that's next. Any wisdom here is greatly appreciated!
I'm sure the consensus is going to be to replace the COPS but before I order them I want a final opinion from the experts. Our 97 Expedition now has 202,000 miles, original COPs, I've finally changed all of the plugs- yes the last 2 back plugs went 202k before I got up the nerve to change them out. They actually didn't look too horrible either. Anyhow, I replaced them and within a couple of weeks developed a hesitation when accelerating. This problem really seems just like a vacuum leak when the PCV boot failed. The idle is good on the car. I've checked the vacuum lines for leaks, replaced the PCV line for the second time so thats good- no other leaks found. Also, I was on a long day trip when this thing started acting up. The engine light came on after running for about 3 or so hours. A scan later produced a P301 code- cylinder 1 problem. I've since pulled the #1 COP and tested for spark- it still fires ok. I haven't checked the injector to see if that affects the operation, that's next. Any wisdom here is greatly appreciated!
1. OEM Motorcraft plugs used?
2. NEW boots?
3. Proper application of Dielectric grease on all boots?
4. ALL NEW COPS highly recommended.
5. Good luck!
6. Paging Jbrew
MGD