missing engine
Thread Starter
|
New User
Joined: Oct 2013
Posts: 9
Likes: 0
missing engine
New here,although I have read a number of posts. Very good and interesting knowledge.
My problem? I have 1999 F250 Superduty,5.4 engine and it misses. New plugs boots, tried a new coilpack and moved it around to different cylinders. No luck. Was in the shop yesterday and they can't find the problem either. It doesn't throw codes and the check engine light doesn't come on. I had a mechanic drive it with a scanner hooked up and it is missing the whole time while driving and does not show anything. Sometimes it will go along time and run perfectly and then all at once start missing again. Would the ECM cause this or like a friend suggested the fuel injectors are causing problems? To me I am thinking the ECM is the problem. What else can I do?
My problem? I have 1999 F250 Superduty,5.4 engine and it misses. New plugs boots, tried a new coilpack and moved it around to different cylinders. No luck. Was in the shop yesterday and they can't find the problem either. It doesn't throw codes and the check engine light doesn't come on. I had a mechanic drive it with a scanner hooked up and it is missing the whole time while driving and does not show anything. Sometimes it will go along time and run perfectly and then all at once start missing again. Would the ECM cause this or like a friend suggested the fuel injectors are causing problems? To me I am thinking the ECM is the problem. What else can I do?
FTE Leadership Emeritus
Joined: Sep 2000
Posts: 23,174
Likes: 1,678
From: Stephensville WI
Welcome to FTE, Craig Minds.
Has anyone looked for pending codes? Not all scanners will pick them up, but if your truck is misfiring, it will show up in a pending error code.
The reason a misfire usually does not set a CEL and an error code is the PCM has a formula, "X" pending misfire codes over "Y" period of time will set a CEL and a code, but the cylinder has to be about dead for that to happen.
Has anyone looked for pending codes? Not all scanners will pick them up, but if your truck is misfiring, it will show up in a pending error code.
The reason a misfire usually does not set a CEL and an error code is the PCM has a formula, "X" pending misfire codes over "Y" period of time will set a CEL and a code, but the cylinder has to be about dead for that to happen.
Thread Starter
|
New User
Joined: Oct 2013
Posts: 9
Likes: 0
I don't know that for sure. When I asked if they found anything, he said they didn't. Their scanner showed #3 misfiring so they put a new plug and boot, then it told them multiple cylinders misfiring. The plugs are Champion and have 3500 miles on them. Don't try to tell me go to Autolite plugs. Had them in there for 15000 miles when this started. Thought it was the plugs and went to the Champions. That's where I am at now.
FTE Leadership Emeritus
Joined: Sep 2000
Posts: 23,174
Likes: 1,678
From: Stephensville WI
These engines don't like Champion plugs. We recommend Motorcraft Platinum plug, which is what they came with from the factory.
Multiple misfires? That sounds more like a vacuum leak or a fuel pressure issue.
Multiple misfires? That sounds more like a vacuum leak or a fuel pressure issue.
Super Moderator
Joined: Aug 2003
Posts: 25,479
Likes: 742
From: Isanti, MN
Most around here will insist that Motorcraft plugs are the only way to go, but I don't think that's your issue. If it's missing while you're driving then it's not a vacuum leak, so it's probably an ignition issue. Does it miss consistently at idle?
If so, simply unplug your injectors or COPs one at a time while the truck idles. With each one the idle should get worse as that cylinder will be misfiring; when you find the cylinder that doesn't get worse then you've found your problem. You can then swap the COP from that cylinder with the adjacent one and see if the miss follows the COP. If it does, then you know you have a bad coil. If not I would look at the injector and possibly compression.
If so, simply unplug your injectors or COPs one at a time while the truck idles. With each one the idle should get worse as that cylinder will be misfiring; when you find the cylinder that doesn't get worse then you've found your problem. You can then swap the COP from that cylinder with the adjacent one and see if the miss follows the COP. If it does, then you know you have a bad coil. If not I would look at the injector and possibly compression.
Thread Starter
|
New User
Joined: Oct 2013
Posts: 9
Likes: 0
missing engine update
Well, I put in all new Motorcraft plugs and it is still missing. Is it possible the ECM is not doing its job? Can that be checked? When it was in the shop and a new plug was put in the #3 cylinder and then it showed multiple cylinders misfiring, could that be the ECM?
Trending Topics
Super Moderator
Joined: Aug 2003
Posts: 25,479
Likes: 742
From: Isanti, MN
Hi Craig,
I moved your new thread into the old one. Having a separate thread with your update makes it virtually impossible for us to keep things straight with what was discussed previously. This way there's some continuity and we can better provide useful input.
It's possible that you have a bad coil driver in your PCM, but I don't think it's likely. Did you ever swap ignition coils to see if the bad cylinder moved with the coil?
I moved your new thread into the old one. Having a separate thread with your update makes it virtually impossible for us to keep things straight with what was discussed previously. This way there's some continuity and we can better provide useful input.
Well, I put in all new Motorcraft plugs and it is still missing. Is it possible the ECM is not doing its job? Can that be checked? When it was in the shop and a new plug was put in the #3 cylinder and then it showed multiple cylinders misfiring, could that be the ECM?
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
Thread Starter
|
New User
Joined: Oct 2013
Posts: 9
Likes: 0
missing engine
Updating once again on the misfiring 5.4. I did look at the video, have not followed through on it, yet. Called the local Ford service dept. and told him what was happening. He said to change all the coil packs at one time, the plug can take out a coil pack. Could change the ones that need to change, but then a week or so change another one. Best to change all of them. I will let you know how that turns out.
By the way, when I told him the plugs I was using, basically that was a mistake. Live and learn.
By the way, when I told him the plugs I was using, basically that was a mistake. Live and learn.
Elder User
Joined: Jan 2002
Posts: 780
Likes: 0
In the words of "MotorAge/TST", "Test, don't guess" In the video that I posted, the test will show weak or failing coils. I had a bad coil on my 2000 F350 V10 five (5) years ago. I replaced the one bad coil pack and I have had no problems since. There are other ways to test if you do not have an automotive scope, but with the scope, which all dealers and most good shops have, you can test for power, ground, signal from the cpu, and waveform. You can test injectors, coil packs, and any other electrical engine components. I know that some shops seem to charge a lot, but if they know what they are doing, the charges will be reasonable because it won't take long to identify the problem. Changing all of the coil packs at once is not necessary unless they test bad. You should test or replace the plug (s) with the coil pack(s) as a bad plug can damage a good coil.
Good luck with it. I hope you get it figured out soon.
Good luck with it. I hope you get it figured out soon.
Thread Starter
|
New User
Joined: Oct 2013
Posts: 9
Likes: 0
Changed all coil packs. Did not miss after driving it for 100 miles or so. When I talked to the service manager at the local Ford dealer, he said you could change the one or two coils, but eventually I will be replacing another in a week, for example, you just as well replace all now. I know the day is over working on it yourself,but sometimes you still want to tackle it yourself if possible. Any way thanks for the help and I will keep watching all the posts for good info.