4.6 misfire underload
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4.6 misfire underload
Ok so I've got a 01 f150 xlt crew cab 4.6 2wd it misses from bout 5 mph to it shifts at 3500 rim or pulling a hill it is driving me crazy cops are good plugs good truck has 280xxx on it have had it almost 3 yrs just started this problem after timing chain started rattling tore it down replaced timing Tensioner And change oil help bout to loose mind
Lead Driver
Joined: Sep 2006
Posts: 7,907
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Use a Scanner to look at the misfire counts for each cylinder.
Go to test mode 6, test 53.
If it shows misfire counts out of limits for any cylinder, check the coil connector and change that coil.
You at a point that just looking at it from the outside is not good enough.
You must use more involved diagnostics.
This is why Scanners are able to look at live data.
Good luck.
Go to test mode 6, test 53.
If it shows misfire counts out of limits for any cylinder, check the coil connector and change that coil.
You at a point that just looking at it from the outside is not good enough.
You must use more involved diagnostics.
This is why Scanners are able to look at live data.
Good luck.
Posting Guru
Joined: Jun 2009
Posts: 1,908
Likes: 20
From: Fort Smith, Arkansas
He is talking about a live data scanner, not a code reader. The scanner is able to read real time data from the engine computer. A code scanner only tells you what codes are set.
If it is actually misfiring, it will have a code set, usually more than 1 code. If you are code scanning it after a misfire and there is no code set, the PCM fuse may be open. Does the "service engine soon" light come on when you first turn the key to "run"?
If it is actually misfiring, it will have a code set, usually more than 1 code. If you are code scanning it after a misfire and there is no code set, the PCM fuse may be open. Does the "service engine soon" light come on when you first turn the key to "run"?
Lead Driver
Joined: Sep 2006
Posts: 7,907
Likes: 143
I specifically said Mode 6, Test 53 to look at the misfire counts for each cylinder.
These counts will not result in a CEL or a regular misfire code, for specific reasons.
This is the first place to go looking when you have no codes set to point you in any direction for misfires.
I don't want to get into the reasons why if you seem not to know the difference between a Reader and Scanner.
Now even with a Scanner you will have to learn how to use it and interpret the data displayed.
You have to understand this is a computer system and you cannot service beyond the code level without a Scanner unless you happen to have a 'stroke' of luck your way.
Chasing with parts drives the cost up, causes you frustration and does not result in solving the problem.
You have to see the problem, and have good proof before you know what to do about it.
Good luck..
These counts will not result in a CEL or a regular misfire code, for specific reasons.
This is the first place to go looking when you have no codes set to point you in any direction for misfires.
I don't want to get into the reasons why if you seem not to know the difference between a Reader and Scanner.
Now even with a Scanner you will have to learn how to use it and interpret the data displayed.
You have to understand this is a computer system and you cannot service beyond the code level without a Scanner unless you happen to have a 'stroke' of luck your way.
Chasing with parts drives the cost up, causes you frustration and does not result in solving the problem.
You have to see the problem, and have good proof before you know what to do about it.
Good luck..
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