The skipping is back!!!
FTE Leadership Emeritus
Joined: Jul 2002
Posts: 42,561
Likes: 423
From: Long Island USA
Definitely move the COPs first, changing the plugs will change too many variables and you'll never know what the real issue was. Until those possibly-marginal COPs start misfiring 20-30K miles from now 
Logistics Pro
Joined: Jan 2002
Posts: 3,733
Likes: 38
Intermittent vacuum leaks are know to cause the same sound feel as a missing cylinder
Be sure the IAC is good
Check them terrible rubber elboes on the hard plastic vacuum lines they deteriorate failry quickly on top of the V10
Make sure you are not feeding it crap fuel or have a loss of fuel pressure problem
chasing a bad COP is a pain... if you have one YOU KNOW is not fireing... a thermal gun temp probe can find the cylinder that is cooler on the exhaust header as a good clue
Be sure the IAC is good
Check them terrible rubber elboes on the hard plastic vacuum lines they deteriorate failry quickly on top of the V10
Make sure you are not feeding it crap fuel or have a loss of fuel pressure problem
chasing a bad COP is a pain... if you have one YOU KNOW is not fireing... a thermal gun temp probe can find the cylinder that is cooler on the exhaust header as a good clue
FTE Leadership Emeritus
Joined: Jul 2002
Posts: 42,561
Likes: 423
From: Long Island USA
Originally Posted by Fredvon4
chasing a bad COP is a pain... if you have one YOU KNOW is not fireing... a thermal gun temp probe can find the cylinder that is cooler on the exhaust header as a good clue
Senior User
Joined: Nov 2006
Posts: 425
Likes: 1
From: Brooksdale, ON
Mine has been playing games with me the last while as well. i have the code reader that will show that i have misses on 1, 2 , 6 ,7 some times one at a time, some times as much as 3 of them at once, i can also tell when i get a miss as the milage goes down, the truck starts to shake and the sound changes to sound like a diesel. I have changed coils around, new plugs and greased them all up, i am now starting to contac clean the plugs on the coils, but what i am wondering is will a COP start to break down like that or will it just quit completely?
FTE Leadership Emeritus
Joined: Jul 2002
Posts: 42,561
Likes: 423
From: Long Island USA
You have some other problem besides ignition, sewerat ...
The chances of having three COPs going out around the same time are pretty slim. Sounds more like you have a vacuum leak - check that rubber elbow in the PCV plumbing as it enters the throttle body. And all the hoses, anyway
The chances of having three COPs going out around the same time are pretty slim. Sounds more like you have a vacuum leak - check that rubber elbow in the PCV plumbing as it enters the throttle body. And all the hoses, anyway
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Freshman User
Joined: Nov 2004
Posts: 25
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From: Middletown CT
I only had time for the first 4 plugs tonight. The ones on the left are the passenger side front to rear and the right is the front drivers side. The electrodes are burned down to a point and white. They are motorcrafts and the truck has about 77,000 miles on it. Took it for a quick ride and it was smooth. I'll go for the others tomorrow, weather permitting.....
Logistics Pro
Joined: Jan 2002
Posts: 3,733
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Snake321
If the Speedo and ABS are still acting up... it usually is the tone ring sensor on the rear diff is failing...usual failure mode is loose connector or broken wire...occasionally there is some crud on the sensor face that a good cleaning will fix
For those interested... the 99 and up SuperDuty trucks take the speed signal as electronic pulses from a magnetic sensor in the rear differential. The signal is sent to the 4 wheel ABS computer first and distributed to the PCM where it is sent to the dash cluster... the loss of this signal will trigger a ABS fault and the speedometer needle will act erratic or dead
On this type system the speedo is claibrated electronically for any tire diameter changes by telling the compoter how many revs per mile the tires are.
Some of the Class C motor coaches and the E-series vans still take the speed reading off the tail shaft of the trany and still have a gear set to change for tire or gear changes to calibrate the speedo
If the Speedo and ABS are still acting up... it usually is the tone ring sensor on the rear diff is failing...usual failure mode is loose connector or broken wire...occasionally there is some crud on the sensor face that a good cleaning will fix
For those interested... the 99 and up SuperDuty trucks take the speed signal as electronic pulses from a magnetic sensor in the rear differential. The signal is sent to the 4 wheel ABS computer first and distributed to the PCM where it is sent to the dash cluster... the loss of this signal will trigger a ABS fault and the speedometer needle will act erratic or dead
On this type system the speedo is claibrated electronically for any tire diameter changes by telling the compoter how many revs per mile the tires are.
Some of the Class C motor coaches and the E-series vans still take the speed reading off the tail shaft of the trany and still have a gear set to change for tire or gear changes to calibrate the speedo
New User
Joined: Mar 2004
Posts: 22
Likes: 0
Well, I think my problems are solved. Changed the plugs and coil boots, swapped the COPS that showed a misfire, and cleared the codes. She is running smoothly now with no codes thrown. I will check again in a few days.
BTW, I had my mechanic do the work. Its been too damn cold and I have been too busy to tackle this one myself. Besides the Porsche thats in pieces in the garage takes most of my energy!
BTW, I had my mechanic do the work. Its been too damn cold and I have been too busy to tackle this one myself. Besides the Porsche thats in pieces in the garage takes most of my energy!
Freshman User
Joined: Nov 2004
Posts: 25
Likes: 0
From: Middletown CT
Originally Posted by Fredvon4
Snake321
If the Speedo and ABS are still acting up... it usually is the tone ring sensor on the rear diff is failing...usual failure mode is loose connector or broken wire...occasionally there is some crud on the sensor face that a good cleaning will fix
For those interested... the 99 and up SuperDuty trucks take the speed signal as electronic pulses from a magnetic sensor in the rear differential. The signal is sent to the 4 wheel ABS computer first and distributed to the PCM where it is sent to the dash cluster... the loss of this signal will trigger a ABS fault and the speedometer needle will act erratic or dead
On this type system the speedo is claibrated electronically for any tire diameter changes by telling the compoter how many revs per mile the tires are.
Some of the Class C motor coaches and the E-series vans still take the speed reading off the tail shaft of the trany and still have a gear set to change for tire or gear changes to calibrate the speedo
If the Speedo and ABS are still acting up... it usually is the tone ring sensor on the rear diff is failing...usual failure mode is loose connector or broken wire...occasionally there is some crud on the sensor face that a good cleaning will fix
For those interested... the 99 and up SuperDuty trucks take the speed signal as electronic pulses from a magnetic sensor in the rear differential. The signal is sent to the 4 wheel ABS computer first and distributed to the PCM where it is sent to the dash cluster... the loss of this signal will trigger a ABS fault and the speedometer needle will act erratic or dead
On this type system the speedo is claibrated electronically for any tire diameter changes by telling the compoter how many revs per mile the tires are.
Some of the Class C motor coaches and the E-series vans still take the speed reading off the tail shaft of the trany and still have a gear set to change for tire or gear changes to calibrate the speedo
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