Truck Jerking/Studdering Around 45-50 mph
#61
12-14-2012, 04:54 AM
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I also stumbled across this thread while doing a search.
I'm usually in the other "diesel" forums, but I'm now in the process of purchasing a 2002 F250 SD, Extended Cab, SB, with the 5.4 to add to my collection.
Will be posting pics of her when I get er, in another thread.
Anyway's, I was hesitant on this purchase because of this "exact" issue.
But the deal and truck are so sweet, I was going to take the gamble,
Bluegrass7, thanks for the informative write-up, reps given.
I'm usually in the other "diesel" forums, but I'm now in the process of purchasing a 2002 F250 SD, Extended Cab, SB, with the 5.4 to add to my collection.
Will be posting pics of her when I get er, in another thread.
Anyway's, I was hesitant on this purchase because of this "exact" issue.
But the deal and truck are so sweet, I was going to take the gamble,
Bluegrass7, thanks for the informative write-up, reps given.
#62
12-15-2012, 08:39 AM
Cargo Master
#63
12-15-2012, 12:39 PM
#64
12-15-2012, 01:11 PM
Cargo Master
Yes there is. Just started her up and she runs just fine....even after a few days of sitting. This is how it has been. Sometimes she does it and sometimes she doesn't. Not much rhyme or reason other than i can USUALLY correlate it to damp weather.
So i'm starting to hunt for cracked boots or cops first.
So i'm starting to hunt for cracked boots or cops first.
#66
12-15-2012, 03:07 PM
Hello all. Here's a little information about my truck. It's a 2000 F-150. Two wheel drive. 5.2 Liter V8. About 133,000 miles on it currently.
Here is the problem I have been having with it recently. Right around 45-50 mph, my truck starts to jerk or studder as I attempt to accelerate gently. It has not been too bad, but it has been prevalent for the past few months. Yesterday, after an 8 hour drive on highways, when I got back onto a regular road, the truck would jerk/studder around 45 mph and it was so bad that I could not drive past 45 mph.
It does not always happen when I drive, but now it is occurring more frequently. I want to bring it into the shop, but want to hear what you guys have to say about this problem first. Thanks!
Here is the problem I have been having with it recently. Right around 45-50 mph, my truck starts to jerk or studder as I attempt to accelerate gently. It has not been too bad, but it has been prevalent for the past few months. Yesterday, after an 8 hour drive on highways, when I got back onto a regular road, the truck would jerk/studder around 45 mph and it was so bad that I could not drive past 45 mph.
It does not always happen when I drive, but now it is occurring more frequently. I want to bring it into the shop, but want to hear what you guys have to say about this problem first. Thanks!
I too thought it was a transmission issue because it wouldn't do it when the overdrive was disengaged. After an exhaustive search for the problem over many days I finally decided to remove the aftermarket spark plugs and put in the plugs from Ford (expensive) and TADA the problem was solved.
One or more of the plugs wasn't putting out the spark that was needed at the point of upshift and caused the engine to bang etc. Even the dealership hadn't heard of this but several months later I found out someone else came in with the same issue and the tech I informed of this issue replaced the plugs he was the shop hero lol. Oh and I found out that the truck he worked on also had aftermarket plugs in it so I guess it pays to stick with OEM!
#67
01-19-2013, 07:56 AM
#68
02-10-2013, 05:42 PM
Note the large number of hits on this subject.
It's a wide spread issue.
Here is what the cause is.
When you get in an OD light throttle drive condition, the EGR opens.
At this point the air/fuel ratio goes very lean "by design intent".
This condition requires the coils to offer higher voltage they "are" designed to give.
If a coil developes shorted turns in it's winding the voltage available drops to a marginal or below level.
This causes a missfire on that cylinder as long as this driving condition exists.
.
As soon as you downshift, increase engine RPM or make any throttle up or down change that takes the EGR out of operation the missfire goes away.
It goes because the air/fuel ratio has richened to the point the faulty coil now has enough voltage to fire the cylinder reliabily such as going from OD to third gear.
Most often this coil condition does not set a DTC code because it comes and goes and in not a 'hard' fault. Once the fault conditon in not present, the record of missfires to set a code is cancelled so no code or CEL is set for you to see.
.
Finding the cylinder at fault.
Four ways;
1. To sub a known good coil in each position until you clear the missfire.
2. Replace all coils but you always have the possibility of a faulty coil in the replacement group.
3. Use a Scanner with a Trap function to freeze frame the live data while drivieng.
4. Have a dealer do a Stress test on all the coils to pick out any that are below limits.
.
Plug replacement:
Sometimes new plugs seem to clear the issue only to return several hundred miles later.
Why;
The new plugs are easier to fire by a 'marginal' coil until their tips begin to errode then the required voltage begins to rise and missfire lightly begins all over again. Yes errosion begins that quick with new plugs.
Bottom line is this kind of issue is quite dynamic and complicated involving several parameters that 'stack up' to cause the end result of studder and missfire.
It can get so bad the faulty coil can send interference back to the computer causing it to stop processing any engine data until it recovers.
This feels like the ignition was tuned off and on at a fast rate, a 'bucking' feeling.
And no, its not the transmission doing any of this.
Good luck.
It's a wide spread issue.
Here is what the cause is.
When you get in an OD light throttle drive condition, the EGR opens.
At this point the air/fuel ratio goes very lean "by design intent".
This condition requires the coils to offer higher voltage they "are" designed to give.
If a coil developes shorted turns in it's winding the voltage available drops to a marginal or below level.
This causes a missfire on that cylinder as long as this driving condition exists.
.
As soon as you downshift, increase engine RPM or make any throttle up or down change that takes the EGR out of operation the missfire goes away.
It goes because the air/fuel ratio has richened to the point the faulty coil now has enough voltage to fire the cylinder reliabily such as going from OD to third gear.
Most often this coil condition does not set a DTC code because it comes and goes and in not a 'hard' fault. Once the fault conditon in not present, the record of missfires to set a code is cancelled so no code or CEL is set for you to see.
.
Finding the cylinder at fault.
Four ways;
1. To sub a known good coil in each position until you clear the missfire.
2. Replace all coils but you always have the possibility of a faulty coil in the replacement group.
3. Use a Scanner with a Trap function to freeze frame the live data while drivieng.
4. Have a dealer do a Stress test on all the coils to pick out any that are below limits.
.
Plug replacement:
Sometimes new plugs seem to clear the issue only to return several hundred miles later.
Why;
The new plugs are easier to fire by a 'marginal' coil until their tips begin to errode then the required voltage begins to rise and missfire lightly begins all over again. Yes errosion begins that quick with new plugs.
Bottom line is this kind of issue is quite dynamic and complicated involving several parameters that 'stack up' to cause the end result of studder and missfire.
It can get so bad the faulty coil can send interference back to the computer causing it to stop processing any engine data until it recovers.
This feels like the ignition was tuned off and on at a fast rate, a 'bucking' feeling.
And no, its not the transmission doing any of this.
Good luck.
One thing I think might be also be making this shaking / cutting out so bad, is when the bad COP is misfiring the computer might be thinking from the unburned fuel in the exhaust that it is running to rich and leaning out the mixture even more.. Makeing even more cylinders misfire..
#69
02-10-2013, 06:26 PM
A problem like this can have far reaching effects at any given time depending specifically on how the coil acts.
It could indeed affect the A/F ratio on that bank.
Very often it can result in a violent jerking as if the ignition were turned off then on very fast such that all cylinders stopped firing for an instant.
What that is is the PCM actually stops processing the whole show for an instant until it recovers control of the action. As the crank is still in rotation the crank sensor is telling the PCM there is still rotation and to process the action as that of a running engine.
Sometimes there is more than one issue at the same time, fooling one who is thinking in a singular fashion.
Sometimes you have to out think the computer when it sneaks these thing in and by you.
Good luck.
It could indeed affect the A/F ratio on that bank.
Very often it can result in a violent jerking as if the ignition were turned off then on very fast such that all cylinders stopped firing for an instant.
What that is is the PCM actually stops processing the whole show for an instant until it recovers control of the action. As the crank is still in rotation the crank sensor is telling the PCM there is still rotation and to process the action as that of a running engine.
Sometimes there is more than one issue at the same time, fooling one who is thinking in a singular fashion.
Sometimes you have to out think the computer when it sneaks these thing in and by you.
Good luck.
#70
02-10-2013, 08:56 PM
A problem like this can have far reaching effects at any given time depending specifically on how the coil acts.
It could indeed affect the A/F ratio on that bank.
Very often it can result in a violent jerking as if the ignition were turned off then on very fast such that all cylinders stopped firing for an instant.
What that is is the PCM actually stops processing the whole show for an instant until it recovers control of the action. As the crank is still in rotation the crank sensor is telling the PCM there is still rotation and to process the action as that of a running engine.
Sometimes there is more than one issue at the same time, fooling one who is thinking in a singular fashion.
Sometimes you have to out think the computer when it sneaks these thing in and by you.
Good luck.
It could indeed affect the A/F ratio on that bank.
Very often it can result in a violent jerking as if the ignition were turned off then on very fast such that all cylinders stopped firing for an instant.
What that is is the PCM actually stops processing the whole show for an instant until it recovers control of the action. As the crank is still in rotation the crank sensor is telling the PCM there is still rotation and to process the action as that of a running engine.
Sometimes there is more than one issue at the same time, fooling one who is thinking in a singular fashion.
Sometimes you have to out think the computer when it sneaks these thing in and by you.
Good luck.
, It was when the engine shut off on the Xway at 75 MPH and I coasted to the shoulder with no power that was the thing that worried me.. Oh yea and the other day when I had my wife with me and the left bank shut down and we drove the last 10 miles in limp home mode in the snow. This was because #7 COP decided to join the party.. And she told me I have to go buy a new truck before I can go back up to the cottage...
#71
02-17-2013, 07:58 PM
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#72
02-17-2013, 08:14 PM
#73
02-18-2013, 11:48 AM
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#74
02-18-2013, 08:37 PM
#75
02-18-2013, 08:45 PM
One thing I think might be also be making this shaking / cutting out so bad, is when the bad COP is misfiring the computer might be thinking from the unburned fuel in the exhaust that it is running to rich and leaning out the mixture even more.. Makeing even more cylinders misfire..
), so as you pointed out, the misfire effects the situation, but it doesn't see the unburned fuel, it sees the UNUSED oxygen, so it ADDS fuel, possibly making more cylinders misfire, etc, etc.