Misfire question
Thread Starter
|
Senior User
Joined: Apr 2006
Posts: 331
Likes: 0
Misfire question
I have done some searching and think that I have a good grasp on this issue.
Recently I have found my truck - 2003 supercrew lariat 5.4 - to misfire. This ONLY happens when there is some load on the truck like going up hill and WOT in 2nd gear. It only starts at high RPM too, like starting at 4500 or so. If I keep in it it will continue to misfire through third gear.
I read on a thread that this may be from an EGR issue - like clogged ports. When I pull the vacuum off of the top of the EGR nothing happens - this leads me to believe that it may be plugged - will this cause my problem?
The only codes I have been getting is random misfire as per my diablosport predator. This issue happens with the tune and without. I am currently driving it back tro stock till I figure this out.
I would like to get this fixed asap as I have a good 7 hour each way trip planned for early August and don't want to be left stranded 7 hours away from civilization.
Thanks in advance.
Recently I have found my truck - 2003 supercrew lariat 5.4 - to misfire. This ONLY happens when there is some load on the truck like going up hill and WOT in 2nd gear. It only starts at high RPM too, like starting at 4500 or so. If I keep in it it will continue to misfire through third gear.
I read on a thread that this may be from an EGR issue - like clogged ports. When I pull the vacuum off of the top of the EGR nothing happens - this leads me to believe that it may be plugged - will this cause my problem?
The only codes I have been getting is random misfire as per my diablosport predator. This issue happens with the tune and without. I am currently driving it back tro stock till I figure this out.
I would like to get this fixed asap as I have a good 7 hour each way trip planned for early August and don't want to be left stranded 7 hours away from civilization.
Thanks in advance.
Thread Starter
|
Senior User
Joined: Apr 2006
Posts: 331
Likes: 0
Hmm, is there a way that I can test the coil packs?
Today I changed out my fuel filter and all of the spark plugs (very tedious work.... for a first timer for me on this truck).
Could this be a fuel issue? like my pump going out? it only starts at 4500 rpm in 2nd gear. There was no difference after changing the filter and plugs... The truck does seem kinda sluggish all around, but really noticable in 2nd gear, sometimes I can barely get out of the gear because it runs out of power and starts misfiring.
Still the only code I get is a "Random Misfire Detected"...
Does the PCM monitor fuel pressure? Can it be viewed using the trip counter like other functions?
Today I changed out my fuel filter and all of the spark plugs (very tedious work.... for a first timer for me on this truck).
Could this be a fuel issue? like my pump going out? it only starts at 4500 rpm in 2nd gear. There was no difference after changing the filter and plugs... The truck does seem kinda sluggish all around, but really noticable in 2nd gear, sometimes I can barely get out of the gear because it runs out of power and starts misfiring.
Still the only code I get is a "Random Misfire Detected"...
Does the PCM monitor fuel pressure? Can it be viewed using the trip counter like other functions?
Thread Starter
|
Senior User
Joined: Apr 2006
Posts: 331
Likes: 0
We don't have any Auto Zone's up here that I know of unfortuneatly otherwise I would - the price sure is right 
Trending Topics
Freshman User
Joined: Nov 2004
Posts: 32
Likes: 0
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
Top 10 Fords at 2026 Carlisle Ford Nationals
Joe Kucinski
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
Thread Starter
|
Senior User
Joined: Apr 2006
Posts: 331
Likes: 0
No one checks codes for free that I know of. I just use my tuner to check them. All that I get is a P0300 - Random Misfire Detected with it.
I used antiseize on the plugs and dielectric grease on the boots.
http://www3.telus.net/jmarling/plugs/
Here are some pics of the plugs, maybe they will tell the story better then I am. Some looked not too bad and some were just gross. Any way to tell if they were original?
By looking at the pics do they describe what may be going on inside my engine. Soon it will going in to Ford to check it out if I can't get this fixed on my own.
The truck has 138000 KM on it now, I bought it with 110000.
I'm thinking a fuel problem or maybe some coils are starting to act up...
I used antiseize on the plugs and dielectric grease on the boots.
http://www3.telus.net/jmarling/plugs/
Here are some pics of the plugs, maybe they will tell the story better then I am. Some looked not too bad and some were just gross. Any way to tell if they were original?
By looking at the pics do they describe what may be going on inside my engine. Soon it will going in to Ford to check it out if I can't get this fixed on my own.
The truck has 138000 KM on it now, I bought it with 110000.
I'm thinking a fuel problem or maybe some coils are starting to act up...
Thread Starter
|
Senior User
Joined: Apr 2006
Posts: 331
Likes: 0
So I think that my problem is due to coils. I will have the dealer do a coil stress test this next weekend to find out. Is it worth it to stick with Motorcraft coils or do aftermarket ones work just as well.
The dealers around here want about $180 per coil, I can get some aftermarket ones from Summitracing for much cheaper, they have Jacobs, Accell and their own brand of Summit ones. They seem to be $25-$35 a piece. Should I just order some up? or do they not work as well as Ford ones? I need to have this fixed up within 2 weeks.
The dealers around here want about $180 per coil, I can get some aftermarket ones from Summitracing for much cheaper, they have Jacobs, Accell and their own brand of Summit ones. They seem to be $25-$35 a piece. Should I just order some up? or do they not work as well as Ford ones? I need to have this fixed up within 2 weeks.
Thread Starter
|
Senior User
Joined: Apr 2006
Posts: 331
Likes: 0
I took it to the dealer to have it checked out. my friend works there so we hooked it up to their computer system. Everything seemed to look fine, all the sensors were within range. But when we did a power balance test #1 and #5 would drop off a little. They did not seem to be too worried about it. They seemed to think that since everything checked out that it may be just carboned up and suggested doing a full cleaning using a flush system they have for the fuel injectors and such.
I think that once my set of 8 coils get in from Summit I will replace #1 and 5 and see how it runs. I really want to get this fixed in the next few days as I am going on a 7-8 hour trip each way on thursday and would like it to be running optimally for it.
I think that once my set of 8 coils get in from Summit I will replace #1 and 5 and see how it runs. I really want to get this fixed in the next few days as I am going on a 7-8 hour trip each way on thursday and would like it to be running optimally for it.