Misfire under load... COP or Plug? Gryphon tuner?
01-31-2011, 02:05 PM
#1
Misfire under load... COP or Plug? Gryphon tuner?
I have an 04' XLT Screw with the 5.4L. When I am at highway speeds and the cruise is set (or not set, its more common with it set) the truck will miss randomly, chug for a second, then run okay for a second or two then miss again. This happens several times while going uphill for any distance. The truck never throws a code, the CEL never comes on or even blinks. It bogs down in od trying to accelerate and misses multiple times before finally downshifting to 3rd.
I have a Gryphon with canned tunes (no custom ones yet) LV: 2, 87 Tow tune, but I am running 89 octane. I increased the timing +1.0 to compensate for the increase in octane points. The tune most likely has nothing to do with it, it did this before the tuner. I need thoughts, is it the COP's (perhaps more than 1) or just garbage plugs? Plugs were done about 30K ago, and COPs I have no idea when they were last done. Truck has 177K on it.
(A.D.D. moment... 177K? This ol' bi*ch needs to choke and die)
I have a Gryphon with canned tunes (no custom ones yet) LV: 2, 87 Tow tune, but I am running 89 octane. I increased the timing +1.0 to compensate for the increase in octane points. The tune most likely has nothing to do with it, it did this before the tuner. I need thoughts, is it the COP's (perhaps more than 1) or just garbage plugs? Plugs were done about 30K ago, and COPs I have no idea when they were last done. Truck has 177K on it.
(A.D.D. moment... 177K? This ol' bi*ch needs to choke and die)
01-31-2011, 02:09 PM
#2
I'm on my second 5.4 triton. Had to change one coil & plug on my old one, current motor is doing the same exact thing. I ran some sea foam in my fuel and it helped, so I'm guessing/hoping I just need to replace my plugs and maybe one coil.
CEL never comes on for me, haven't checked for misfire codes yet.
try some google searches on "5.4 misfire under load"
CEL never comes on for me, haven't checked for misfire codes yet.
try some google searches on "5.4 misfire under load"
Last edited by LaAngler; 01-31-2011 at 02:12 PM.
01-31-2011, 02:14 PM
#3
Mine is doing the same exact thing. I ran some sea foam in my fuel and it helped, so I'm guessing/hoping I just need to replace my plugs and maybe one coil.
CEL never comes on for me, haven't checked for misfire codes yet.
try some google searches on "5.4 misfire under load"
CEL never comes on for me, haven't checked for misfire codes yet.
try some google searches on "5.4 misfire under load"
I ran some seafoam through mine just a few days ago and I got some HORRIBLE ping at 2000rpm or more. I was too scared to goose it and burn it off so I just limped it back to the shop and let her idle for a while. So, seafoam is a GREAT product, but perhaps on my worn out motor it's not the best of things. BTW it didnt help at all, the miss is still very much so present.
Anyone have an idea?
01-31-2011, 02:49 PM
#4
^ drinks KC Tea
drive the **** out of it. on my truck ive replaced every coil 2 times at a minimum. the miss isnt gonna wreck anything if ya just drive it a bit. when it started to miss bad i just hammered on it as much as i could and the cel will start flashing and eventually find which cylinder misses. i just check every so often as im driving till i get a code cuz sometimes the computer will get a code but not flash the light
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MyBigRed89 (10-20-2022)
10-17-2022, 12:58 PM
#5
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drive the **** out of it. on my truck ive replaced every coil 2 times at a minimum. the miss isnt gonna wreck anything if ya just drive it a bit. when it started to miss bad i just hammered on it as much as i could and the cel will start flashing and eventually find which cylinder misses. i just check every so often as im driving till i get a code cuz sometimes the computer will get a code but not flash the light
10-17-2022, 01:25 PM
#6
