f 250 ,4.6 engine
Fleet Mechanic
Joined: Aug 2008
Posts: 1,446
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From: NE Iowa JD Country
1st off you probably have a low grade miss fire..from a weak COP/COPs, very common.
any CEL present...scan for tripped codes??
what has been done to correct this so far?
Thread Starter
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Freshman User
Joined: Nov 2010
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i changed spark plugs,,,ran a test on the two coils ,they seem to be okay,this engine as 400.000 km on it
Lead Driver
Joined: Sep 2006
Posts: 7,907
Likes: 143
Lets stop here a moment and get a more clear idea what is happening.
What does a 'mess' mean?
Is it an actual backfire or a missfire. The difference is large in terms of causes.
Is there trouble light on?
Have codes been looked for?
What have 'you' done?
Until there is some clairity, no amount of guessing will be useful.
What does a 'mess' mean?
Is it an actual backfire or a missfire. The difference is large in terms of causes.
Is there trouble light on?
Have codes been looked for?
What have 'you' done?
Until there is some clairity, no amount of guessing will be useful.
Thread Starter
|
Freshman User
Joined: Nov 2010
Posts: 31
Likes: 0
Lets stop here a moment and get a more clear idea what is happening.
What does a 'mess' mean?
Is it an actual backfire or a missfire. The difference is large in terms of causes.
Is there trouble light on?
Have codes been looked for?
What have 'you' done?
Until there is some clairity, no amount of guessing will be useful.
What does a 'mess' mean?
Is it an actual backfire or a missfire. The difference is large in terms of causes.
Is there trouble light on?
Have codes been looked for?
What have 'you' done?
Until there is some clairity, no amount of guessing will be useful.
Lead Driver
Joined: Sep 2006
Posts: 7,907
Likes: 143
You have to have a code set if there is a constant missfire.
Why; the crank sensor measures the rotation time of each cylinder after fireing it.
If one cylinder is slower no matter the cause than the average of the other 7, that cylinder is IDed with a code.
Why; the crank sensor measures the rotation time of each cylinder after fireing it.
If one cylinder is slower no matter the cause than the average of the other 7, that cylinder is IDed with a code.
Thread Starter
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Freshman User
Joined: Nov 2010
Posts: 31
Likes: 0
for some reason i have no check engine light......what test can i do to find out if its the crank sensor ,,thanks for your input
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Lead Driver
Joined: Sep 2006
Posts: 7,907
Likes: 143
I didn't say it was the crank sensor.
I explained how the system detects a missfire using the crank sensor to measure rotation time.
Re read the explaination.
Obviously a missfire will not apply power to the crank for that rotation duration and will be slower.
If you feel it the system will detect it.
Maybe you have some other issue you think is a missfire.
Does the CEL lamp light just before you crank the motor?
If not the lamp is blown so you won't see it.
I would still put a Scanner on and see if there are any codes set.
I explained how the system detects a missfire using the crank sensor to measure rotation time.
Re read the explaination.
Obviously a missfire will not apply power to the crank for that rotation duration and will be slower.
If you feel it the system will detect it.
Maybe you have some other issue you think is a missfire.
Does the CEL lamp light just before you crank the motor?
If not the lamp is blown so you won't see it.
I would still put a Scanner on and see if there are any codes set.
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Lead Driver
Joined: Sep 2006
Posts: 7,907
Likes: 143
The only way to test coils is either by substitution or 'stress' testing.
Simple meter testing will not do.
A hard failure will set a code for an open primary or secondary such that testing is already done by system detection of the hard fault and shows as a code for that cylinder..
Intermitant failures are usually shorted turns that lower voltage output and can be temperature sensitive.
Simple meter testing will not do.
A hard failure will set a code for an open primary or secondary such that testing is already done by system detection of the hard fault and shows as a code for that cylinder..
Intermitant failures are usually shorted turns that lower voltage output and can be temperature sensitive.
Lead Driver
Joined: Sep 2006
Posts: 7,907
Likes: 143
Now you have something to work with instead of wandering around.
Code 141 is Ox sensor bank 1 rear heater circuit fault.
171 is bank 1 system lean.
402 is EGR system excessive flow detected.
1409 is EGR vacuum regulator open or shorted.
302, 303, 304 are cylinders 2,3,4 missfires.
You have a number if issues all at the same time.
.
Who or what happened to cause all these issues?
************************************************** *******
Some troubles may be causing other unintended issues, so clearing some out may also clear others that were being affected.
Get any cylinder missfires corrected first to protect the cats from burning out.
141 may be an open in the harness going back to the rear sensor on that bank.
The 1409 and 402 likely are related.
171 is usually an intake air leak.
I would power down the PCM a minute or two, reconnet, run the truck a few miles, then see what codes come back so you have the latest trouble history and not chase old trouble codes.
.
You understand now why I came in and said stop with the guessing?
Your dealing with a computer system.
Good luck.
Code 141 is Ox sensor bank 1 rear heater circuit fault.
171 is bank 1 system lean.
402 is EGR system excessive flow detected.
1409 is EGR vacuum regulator open or shorted.
302, 303, 304 are cylinders 2,3,4 missfires.
You have a number if issues all at the same time.
.
Who or what happened to cause all these issues?
************************************************** *******
Some troubles may be causing other unintended issues, so clearing some out may also clear others that were being affected.
Get any cylinder missfires corrected first to protect the cats from burning out.
141 may be an open in the harness going back to the rear sensor on that bank.
The 1409 and 402 likely are related.
171 is usually an intake air leak.
I would power down the PCM a minute or two, reconnet, run the truck a few miles, then see what codes come back so you have the latest trouble history and not chase old trouble codes.
.
You understand now why I came in and said stop with the guessing?
Your dealing with a computer system.
Good luck.
Lead Driver
Joined: Sep 2006
Posts: 7,907
Likes: 143
Sounds good.
1506 is an operational fault with the IAC.
May be stuck to far open.
Remove it and get spray cleaner to free the pintel and flush out all the carbon and gum.
Hold the throttle open and spray clean all around the inside of the throttle body and plate until it runs out on a cloth or paper towel clean
then reboot the PCM.
Do a cold start with the lights on and the fan running so the PCM has about the worst case starting conditons to adjust to.
After the motor is fully warmed, go for a drive and do several hot restarts and it should be perfect starts both cold and hot from then on unless there is some other issue.
Hot idle should be around 650 rpm.
Good luck.
1506 is an operational fault with the IAC.
May be stuck to far open.
Remove it and get spray cleaner to free the pintel and flush out all the carbon and gum.
Hold the throttle open and spray clean all around the inside of the throttle body and plate until it runs out on a cloth or paper towel clean
then reboot the PCM.
Do a cold start with the lights on and the fan running so the PCM has about the worst case starting conditons to adjust to.
After the motor is fully warmed, go for a drive and do several hot restarts and it should be perfect starts both cold and hot from then on unless there is some other issue.
Hot idle should be around 650 rpm.
Good luck.
Thread Starter
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Freshman User
Joined: Nov 2010
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i m back ,,go to take the ford far a drive and its spiting and kinda back firing with no power ,when i take of its like a whistling sound can hear it from in side the cab than it will disapear and come back when i take of,,,would a code 1506 cause this ? thanks