misfire with no check engine light or codes
Thread Starter
|
Freshman User
Joined: Dec 2003
Posts: 27
Likes: 0
misfire with no check engine light or codes
I have a 98' Expy and it is misfiring now at idle and under acceleration. I do not get a check engine light and when I use a code reader, it does not find any codes. 126K on the 5.4L and I have changed the #4 COP twice and the #1 COP once. Original plugs changed at 90K, leaking heater hose over #4 changed 2 years ago and the tranny was serviced 12 months ago.
Any ideas on how to narrow my troubleshooting efforts? The check engine light illuminates on start up. Any ideas on why the check engine light is not functioning? Any ideas would be great, this forum has saved sooo much time and money. All of your thoughts are greatly appreciated.
Rodney
98', 5.4L, 126K, Uni-Filter, Amsoil
3" cat back w/ FlowMaster, Nokian WR
Any ideas on how to narrow my troubleshooting efforts? The check engine light illuminates on start up. Any ideas on why the check engine light is not functioning? Any ideas would be great, this forum has saved sooo much time and money. All of your thoughts are greatly appreciated.
Rodney
98', 5.4L, 126K, Uni-Filter, Amsoil
3" cat back w/ FlowMaster, Nokian WR
Hotshot
Joined: Jan 2004
Posts: 19,762
Likes: 1,079
From: St Louis
Hotshot
Joined: Jan 2004
Posts: 19,762
Likes: 1,079
From: St Louis
Originally Posted by Thrower20
The link did not connect to another thread.
Rodney
Rodney
What I did was enter "MISFIRECNT" into the SEARCH box...
Looks like the forum software only saves the SEARCH results for a short time.... Try that explicit SEARCH to return previous posts.
Steve
New User
Joined: Mar 2007
Posts: 14
Likes: 0
I am having a similar problem with a vehicle at work. It misses at idle and under a load. It is an intermittent problem. I replaced the spark plugs and boots and the problem remained. After a little research on the internet I am leaning toward a bad DPFE (differential pressure feedback EGR). I ordered a new one but the part did not show up by the time I got off of work. I am sure that is the problem and I will post back with the results. This is the first time I had this problem. Usually replacing the spark plugs and boots take care of the problem.
Senior User
Joined: Dec 2003
Posts: 141
Likes: 0
From: kansas city kansas
had same problems with mine. i would replace plugs and would still get misfire. found out that i had a bad coil i also put on a nice set a plug wires and the expy runs like a champ. 
Trending Topics
Thread Starter
|
Freshman User
Joined: Dec 2003
Posts: 27
Likes: 0
Thanks for the replies, yesterday I got the enigine light to flash once per second. I got a P0300 code random misfire and in the freeze frame section I got:
Fuel sys 1 - CL; Fuel sys 2 - CL-Fault; Calc Load (%) - 56.08; ECT (F) - 192; STFT B1 (%) - -3.91.
I understand the misfire, which does not help a whole lot, but does anyone understand the freeze frame information and how can I use it.
Thanks,
Rodney
Fuel sys 1 - CL; Fuel sys 2 - CL-Fault; Calc Load (%) - 56.08; ECT (F) - 192; STFT B1 (%) - -3.91.
I understand the misfire, which does not help a whole lot, but does anyone understand the freeze frame information and how can I use it.
Thanks,
Rodney
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalytic 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
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
Thread Starter
|
Freshman User
Joined: Dec 2003
Posts: 27
Likes: 0
Here's the rest of the data; LTFT B1 (%) - 10.94, STFT B@ (%) - -4.69, LTFT B2 (%) - 10.94, RPM 1987, Vehicle spd 66 mph. This reader can not read mode 6 data. I will check with a neighbor, he might have one that will.
Thanks,
Rodney
Thanks,
Rodney
New User
Joined: Mar 2007
Posts: 14
Likes: 0
Ok got back to work today and the DPFE sensor I ordered showed up. I verified that the misfire was still happening. Of course it was. I installed the DPFE sensor and checked for a misfire-it was gone. The truck ran perfect.
Hotshot
Joined: Jan 2004
Posts: 19,762
Likes: 1,079
From: St Louis
Originally Posted by mallen88
Ok got back to work today and the DPFE sensor I ordered showed up. I verified that the misfire was still happening. Of course it was. I installed the DPFE sensor and checked for a misfire-it was gone. The truck ran perfect.
Try not to hijack threads...
Steve
Thread
Thread Starter
Forum
Replies
Last Post
PEPpfts
1997 - 2006 Expedition & Navigator
35
Jan 29, 2012 11:53 PM
