04-13-2015, 02:22 PM
Last edit by: IB Advertising
5.4L Misfire
Misfiring can be caused be many issues. Fuel filters seem to be the leading cause. Find out what other issues your truck may have to be cause these problems
Helpful Advice
Misfiring can be caused be many issues. Fuel filters seem to be the leading cause. Find out what other issues your truck may have to be cause these problems
Helpful Advice
5.4L Misfire/Hesitation Issues
#151
08-02-2014, 01:39 AM
Hi you all! this is my first time on this site and I really like it, there is a lot of helpful information, i have a problem with my 2003 F150 CC (4X4), 5.4L. truck kept giving me code cyl #4 misfire! Missing badly on idle! after replacing plugs, coil pack, injector, etc. mechanic said there was a coolant leak going inside the cylinder and suggested to do the heads and I did! Well I am still having same problem, visual inspection on block looked OK. How can I make sure block is Ok, I will really appreciate your assistance on this. Thank you all!
By applying compressed air to each cylinder in turn (with that cylinders intake & exhaust valves closed) isolating the faulty cylinder?
Did he remove the degas cap and look for bubbles?
Or did perform a leak down test.
Were there combustion gases in the coolant?
Perhaps a compression check....what?
You have to do something to confirm that, - ask him what he did. Can't just say you have a coolant leak in there without verification.
#152
12-15-2014, 09:09 PM
Depending on the mileage and how low you've run the fuel in the tank over the years, the fuel pump could be letting out. Its probably having trouble maintaining pressure when your engine requires it under a load but can push hard enough to run the vehicle under its own weight. I had one replaced in my 99 F150 before I sold her off, it was at 123k miles. It would run fine for the most part under light accel but if I got into it, she started bucking and around 55 to 60mph you could tell it was having trouble.
#153
12-15-2014, 09:52 PM
#154
12-23-2014, 12:22 PM
I know this is an old thread but need help. I have a '99 expedition with the 5.4L v8 and am having these same issues. Also I have had an issue with it just dying on the road while driving. After it stalls I just turn off the ignition and then it will start right back up???? Any help on this???
#156
01-05-2015, 05:25 AM
07 F-150 4x4 5.4L V-8 Multiple Misfire
I have an 2007 F-150 5.4L V-8 4X4 With just over 92,000 Miles on it. So at around 90,000 miles the truck started misfiring and hesitating on acceleration and at Idle all day long no matter how long I drove it. so I assumed it was time for Plugs, and within a week I went and bought Motor-craft OEM plugs and changed all 8 of them. As soon as I finished and started driving the truck the misfiring stopped and the truck ran great.
After about 3 months or so it has now started to misfire again only this time it will misfire when I start it up in the Morning for about 15-20 minutes until I stop somewhere and shut off the engine. Then when I Restart the engine it will run completely fine the rest of the day no problems at all until the next morning and so on. So this time It actually threw a code on the OBD with a check engine light, whereas previously no check engine light ever showed up. So I had the code read and it reads Multiple Misfire cylinders 3, 5 and 7. Since I had just changed plugs I figured it couldn't be plugs again but I pulled 3, 5 and 7 anyways and checked them only to find that they were completely fine and still sparking. So next I thought maybe it's a fuel problem, (Even though I would think if it was the filter it would happen all the time or intermittently not just in the morning or when the engine cold starts) so I changed the fuel filter and checked the pressure at the rails (The filter did look like it needed changed so I changed it but pressure was normal). Start it up and still no difference, it's actually getting worse.
I'm at somewhat of a loss here I just cant seem to understand whats going on under the hood. I grew up working on cars/trucks all my life, I have a fairly good idea of what I'm doing as far as working on the truck but it almost seems as if its a ECU problem or electrical but it doesn't say anything like that in OBD just multiple misfire. What doesn't make sense to me is that I start it in the morning and drive 5 miles, stop at the gas station, when I restart it I got no problems for the day(The check engine Light usually blinks during misfire but stays on solid after it starts to run normal).
Could a MAF Sensor or an O2 Sensor be causing this until its warmed up?
If anyone could give some insight to what may be going on I would really appreciate it. I am the original owner of the truck and its never been off road 4 wheeling or anything crazy it's towed a few things but mainly highway and city use.
After about 3 months or so it has now started to misfire again only this time it will misfire when I start it up in the Morning for about 15-20 minutes until I stop somewhere and shut off the engine. Then when I Restart the engine it will run completely fine the rest of the day no problems at all until the next morning and so on. So this time It actually threw a code on the OBD with a check engine light, whereas previously no check engine light ever showed up. So I had the code read and it reads Multiple Misfire cylinders 3, 5 and 7. Since I had just changed plugs I figured it couldn't be plugs again but I pulled 3, 5 and 7 anyways and checked them only to find that they were completely fine and still sparking. So next I thought maybe it's a fuel problem, (Even though I would think if it was the filter it would happen all the time or intermittently not just in the morning or when the engine cold starts) so I changed the fuel filter and checked the pressure at the rails (The filter did look like it needed changed so I changed it but pressure was normal). Start it up and still no difference, it's actually getting worse.
I'm at somewhat of a loss here I just cant seem to understand whats going on under the hood. I grew up working on cars/trucks all my life, I have a fairly good idea of what I'm doing as far as working on the truck but it almost seems as if its a ECU problem or electrical but it doesn't say anything like that in OBD just multiple misfire. What doesn't make sense to me is that I start it in the morning and drive 5 miles, stop at the gas station, when I restart it I got no problems for the day(The check engine Light usually blinks during misfire but stays on solid after it starts to run normal).
Could a MAF Sensor or an O2 Sensor be causing this until its warmed up?
If anyone could give some insight to what may be going on I would really appreciate it. I am the original owner of the truck and its never been off road 4 wheeling or anything crazy it's towed a few things but mainly highway and city use.
#157
02-08-2015, 10:46 PM
#158
02-09-2015, 12:32 AM
#159
03-13-2015, 06:38 PM
Misfires & hesitatiom
I also spent a lot of time trying to figure out a hesitating misfire problem on my v 8 van! Almost a yr and over 600 in parts! It ended up being the egr tube! My first van had 400,000 miles on it and one of the small lines had so much carbon in it no air was getting through its impossible to unclog! Part is 73.00 thru the dealership and incredibly hard to replace my husband use a half moon movable end to get it off in the end! My second van had the same issue tube was changed runs like a champ!
#160
03-17-2015, 12:25 AM
I've got to admit reading back through this topic is making me laugh. I came to this forum to learn. Some have taken the time to teach, others offered suggestions while others simply impathized with what's going on. All good stuff. Then there are those few that always seem to find a way to be critical and feel some need to put others down. What a complete waste of time and energy.
Just for the record I have already taken the truck to a well qualified, experienced, lifelong mechanic. I've also spoken to two other men who are well known locally for their mechanical know-how. So far all three are stumped. We've and or they have run all kinds of tests on this truck. Parts have been replaced, etc, etc, etc. and still no solution. I thought maybe, just maybe, if I kept coming back here someone might hit the jackpot but unfortunately that hasn't happened. In the meantime my truck is going back in the shop this week and we will start all over.
Finally, as of this post I am officially out of this discussion. It is obvious that I've received all the constructive insight and help I'm going to get. In all sincerity thank you so much for your help. We'll figure it out from here.
Just for the record I have already taken the truck to a well qualified, experienced, lifelong mechanic. I've also spoken to two other men who are well known locally for their mechanical know-how. So far all three are stumped. We've and or they have run all kinds of tests on this truck. Parts have been replaced, etc, etc, etc. and still no solution. I thought maybe, just maybe, if I kept coming back here someone might hit the jackpot but unfortunately that hasn't happened. In the meantime my truck is going back in the shop this week and we will start all over.
Finally, as of this post I am officially out of this discussion. It is obvious that I've received all the constructive insight and help I'm going to get. In all sincerity thank you so much for your help. We'll figure it out from here.
#162
09-21-2015, 05:18 PM
f150 hesitating and making small explosionsin the exhaustI
Hi I have 97 f150 5.4 liter it working fine.I took it yesterday to the car wash do a engine wash.on it and when. I left I noticed it was hesitating and backfireing a lil bit and lost some power what can it.be they told me not to worry tht maybe a sensor.got.wet.just let the engine dry and it should stop doing that any ideas thx in advance
#163
09-21-2015, 07:05 PM
You probably drowned the cops and possibly filled the plug wells with water. You should NEVER wash a cop-equipped engine.
Pull all the cops, dry them out, and blow out the plug wells with an air compressor. Reinstall using dielectric grease, and if it still misses start replacing cops.
"cop" = coil on plug
Pull all the cops, dry them out, and blow out the plug wells with an air compressor. Reinstall using dielectric grease, and if it still misses start replacing cops.
"cop" = coil on plug
#164
02-05-2016, 08:40 PM
#@%$&* Everytime I think I have this thing fixed....ARGGG
This morning on the way to work the truck starting missing badly and threw a code showing a misfire on #8. This follows a misfire on #7 and #4 all after replacing plugs & cops. Once I delete the code it shows a misfire somewhere else. While idling in park or neutral it is fairly smooth but when in gear it gets worse. While driving with no load (very easy) it's smooth but as soon as I gas it the miss reappears. On a hill it is horrible. When in gear and under the hood I hear a definite gasping for air at the air filter. I completely removed the intake; cleaned the MAF; checked the filter and reinstalled everything but no improvement. Looked over the TB and it appears relatively clean. Basically it seems to have to do with the air/fuel mix/vacuum but all the hoses appear to be good. Thought about the EGR and MAF but I don't want to just start replacing high dollar items without really having a clue what the problem may be. This is getting old quickly. Ideas?
One last thing...I'm getting a slight rich smell.
This morning on the way to work the truck starting missing badly and threw a code showing a misfire on #8. This follows a misfire on #7 and #4 all after replacing plugs & cops. Once I delete the code it shows a misfire somewhere else. While idling in park or neutral it is fairly smooth but when in gear it gets worse. While driving with no load (very easy) it's smooth but as soon as I gas it the miss reappears. On a hill it is horrible. When in gear and under the hood I hear a definite gasping for air at the air filter. I completely removed the intake; cleaned the MAF; checked the filter and reinstalled everything but no improvement. Looked over the TB and it appears relatively clean. Basically it seems to have to do with the air/fuel mix/vacuum but all the hoses appear to be good. Thought about the EGR and MAF but I don't want to just start replacing high dollar items without really having a clue what the problem may be. This is getting old quickly. Ideas?
One last thing...I'm getting a slight rich smell.
Depending on the year of your truck there is a module above the spare tire that tends to corrode and short out that can cause misfires. I forget the name of the module but I changed a few out on F-150's when I was a Ford tech.