V10 Miss after plug change
#1
V10 Miss after plug change
About a month ago I changed the plugs on my EX to see if I might pick up a few tenths on my mpg. There was no real issue, but I wasn't sure when they were done last. I used Autolite platinum's(AP103). Since I changed them The truck has a hard miss during acceleration. It feels like it is missing on multiple cylinders. It is most noticeable below 2000 RPMS. During hard acceleration it almost clears out, but the the truck feels like a pig. There is also a miss at idle, but it goes away if the truck is in park, or neutral. Thinking that it may be my choice of plugs I went back last week and replaced them again with motorcrafts. Still having the same issue. Have scanned the truck with both the Torque app, and an sct scanner and its not throwing any codes. I'm at a loss. In the last year I have replaced the fuel pump, and the filter so I'm ruling those out. any help would be appreciated
#4
If you had no issue with missing before the original plug change, it has to be something that happened with the change. Did you change the boots? They can develop small cracks and cause a miss, especially after they were disturbed. If the boots are new, try removing and reseating the COP/boots 1 at a time and see if you can track down the balky cylinder.
On edit, I see I am a little slow on the boot suggestion.
On edit, I see I am a little slow on the boot suggestion.
#7
If you don't have any codes from the Torque app or SCT you may need to use a live scanner. These will be more precise in identifying which cylinder is missing. May want to check fuel pressure just to rule it out. I would check mostly the idle pressure as that's where the issue is noticable.
Trending Topics
#8
Use the Torque app
Select "Test Results"
Wait a bit, then scroll down to TID $53
Look at CID $01-$0A (10)
Those are the misfire counts for cylinders 1-10 respectively. An engine with no misfires will show either zero count or the entry will be blank.
Once you know which cylinder(s) are the problem, it's a lot easier to narrow down the issue. Look in particular for connectors clips for the injectors and the COPs that are broken and not maintaining good connections. Then, as needed, you can swap COPS between "good" cylinders and "bad" cylinders to see if the misfire follows the COP or stays with the cylinder.
Select "Test Results"
Wait a bit, then scroll down to TID $53
Look at CID $01-$0A (10)
Those are the misfire counts for cylinders 1-10 respectively. An engine with no misfires will show either zero count or the entry will be blank.
Once you know which cylinder(s) are the problem, it's a lot easier to narrow down the issue. Look in particular for connectors clips for the injectors and the COPs that are broken and not maintaining good connections. Then, as needed, you can swap COPS between "good" cylinders and "bad" cylinders to see if the misfire follows the COP or stays with the cylinder.
#9
Use the Torque app
Select "Test Results"
Wait a bit, then scroll down to TID $53
Look at CID $01-$0 (10)
Those are the misfire counts for cylinders 1-10 respectively. An engine with no misfires will show either zero count or the entry will be blank.
Once you know which cylinder(s) are the problem, it's a lot easier to narrow down the issue. Look in particular for connectors clips for the injectors and the COPs that are broken and not maintaining good connections. The, as needed, you can swap COPS between "good" cylinders and "bad" cylinders to see if the misfire follows the COP or stays with the cylinder.
Select "Test Results"
Wait a bit, then scroll down to TID $53
Look at CID $01-$0 (10)
Those are the misfire counts for cylinders 1-10 respectively. An engine with no misfires will show either zero count or the entry will be blank.
Once you know which cylinder(s) are the problem, it's a lot easier to narrow down the issue. Look in particular for connectors clips for the injectors and the COPs that are broken and not maintaining good connections. The, as needed, you can swap COPS between "good" cylinders and "bad" cylinders to see if the misfire follows the COP or stays with the cylinder.
#10
It takes a while and you might get different results depending on if your truck is a california model or 49 state model.
I have a california model (obd2) and it reports all cylinders. Most are 0 but sometimes I get a low misfire count (usually less than 200)
Engine runs fine other than pinging at higher rpm under load so I might need new coils as well but for regular driving it runs great.
The non-california models (which are not obd2 compliant) might not report the individual cylinders)
I have a california model (obd2) and it reports all cylinders. Most are 0 but sometimes I get a low misfire count (usually less than 200)
Engine runs fine other than pinging at higher rpm under load so I might need new coils as well but for regular driving it runs great.
The non-california models (which are not obd2 compliant) might not report the individual cylinders)
#11
Pretty much. See https://www.ford-trucks.com/forums/1...bd1-obdll.html, especially post # 35 as I figured it out on my 01 OBD1 49-state Super Duty last fall.
In that case, cylinders #1 & #6 were the culprits. I replaced both COPs (about $13 each from Rock Auto) back in August of last year and it's been fine since then.
See thread referenced above for updated info.
In that case, cylinders #1 & #6 were the culprits. I replaced both COPs (about $13 each from Rock Auto) back in August of last year and it's been fine since then.
The non-california models (which are not obd2 compliant) might not report the individual cylinders)
#13
#15
Check your connectors on COPs and injectors, making sure all are intact. These are sometimes brittle and easy to break during plug changes.
A broken one can work loose and cause a miss.
Mine (2000 EX) has same issue in same RPM range. COPs help - have changed 3, am working through all slowly.
I'm using only the Motorcraft DG-508s due to some of the comments made on this board.
Some of my issues are surely the connectors (many broken) so I have purchased all new COP & injector connectors and intend to rework harness (no longer available new for my version of v-10). We'll see how it goes.
I can affirm some of the comments made about corrosion on the cylinders under the cowl. My #10 was heavy contaminated; cleaned it up and put in new COP and miss got "better". You can find the bad cylinder with a vacuum gage and a good ear by cycling through each, removing connector on injector and observing impacts.
great site for diagmostics on this issue -
Part 1 -Testing FORD Coil-on-Plug (COP) Coils.
Found this excellecnt site for Fords.
Part 1 -Testing FORD Coil-on-Plug (COP) Coils.
A broken one can work loose and cause a miss.
Mine (2000 EX) has same issue in same RPM range. COPs help - have changed 3, am working through all slowly.
I'm using only the Motorcraft DG-508s due to some of the comments made on this board.
Some of my issues are surely the connectors (many broken) so I have purchased all new COP & injector connectors and intend to rework harness (no longer available new for my version of v-10). We'll see how it goes.
I can affirm some of the comments made about corrosion on the cylinders under the cowl. My #10 was heavy contaminated; cleaned it up and put in new COP and miss got "better". You can find the bad cylinder with a vacuum gage and a good ear by cycling through each, removing connector on injector and observing impacts.
great site for diagmostics on this issue -
Part 1 -Testing FORD Coil-on-Plug (COP) Coils.
Found this excellecnt site for Fords.
Part 1 -Testing FORD Coil-on-Plug (COP) Coils.