Sputters in the morning
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Joined: Oct 2008
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Sputters in the morning
OK - here's what I thought was going to be easy. Truck acted up one morning and it kind of cleared up..... missing sputtering. I got a code for Cylinder 4 misfire, so I swapped out he coil (5.4 in a 2003). thought that fixed it, but 2 days later same thing? It runs fine after about 600 ft or so of driving and I'm good the rest of the day. Next morning same thing..... I put new plugs in her about 4000 or 5000 mile ago and it was fine for many months. kind of at a loss here? Why is it clearing up..... bad new coil pack? I guess I could swap it with another one and see if it moves huh..? Weird.
Senior Member
Joined: Jan 2002
Posts: 5,994
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From: Wilmington,NC
clogged injector could cause a misfire too. Try a bottle of Gumout for high mileage engines.
My 02 on rare occasions misses really bad for a few seconds when I first start it and then smoothes out. The first time it did it was several years ago. May be related to first start after sitting a few days or wet weather. Could be moisture related in my case.
My 02 on rare occasions misses really bad for a few seconds when I first start it and then smoothes out. The first time it did it was several years ago. May be related to first start after sitting a few days or wet weather. Could be moisture related in my case.
Senior Member
Joined: Jul 2004
Posts: 6,200
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From: Easton, Pa.
If you have cold start and cold drive-away issues then clears up, there is a fault with CHT or IAT sensor.
Cold start uses these sensor to determine the cold start setuo and fueling and ignition timing advance until OX sensors the motor begins to heat.
The best way is to use a Scanner to look at these values before starting and watch them during warm up for improper operation.
A misfire or stumble is lack of fuel 'richness' for a cold engine.
Same a not choking a carbed engine when it's cold.
Good luck.
Cold start uses these sensor to determine the cold start setuo and fueling and ignition timing advance until OX sensors the motor begins to heat.
The best way is to use a Scanner to look at these values before starting and watch them during warm up for improper operation.
A misfire or stumble is lack of fuel 'richness' for a cold engine.
Same a not choking a carbed engine when it's cold.
Good luck.
Last edited by Bluegrass; Dec 1, 2016 at 08:08 PM.
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I have a 03 f150 5.4 that was doing the same thing I put a bottle of Lucas injector cleaner in it and I haven't noticed it do it lately. I had put a new set of motorcraft platinum plugs in it before the gas treatment and it still done it. I think it's got something to do with the injectors when it's cold. I'm not really sure but I would like to know myself.
Last edited by Lucas Phillips; Nov 30, 2016 at 12:24 AM.
Thread Starter
|
Member
Joined: Oct 2008
Posts: 18
Likes: 0
If you have cold start and cold drive-away issues then clears up, there is a fault with CHT or IAT sensor.
Cold start uses these sensor to determine the cold start setuo and fueling and ignition timing advance until OX sensors the motor begins to heat.
The best way is to use a Scanner to look at these values before starting and watch them during warm up for improper operation.
A misfire or stumble is lack of fuel 'richness' for a cold engine.
Same a not choking a carbed engine when it's cold.
Good luck.
Cold start uses these sensor to determine the cold start setuo and fueling and ignition timing advance until OX sensors the motor begins to heat.
The best way is to use a Scanner to look at these values before starting and watch them during warm up for improper operation.
A misfire or stumble is lack of fuel 'richness' for a cold engine.
Same a not choking a carbed engine when it's cold.
Good luck.