So, I recently bought a '99 expedition XLT with the triton 5.4L for a great price because it was running rough (2 misfiring cylinders and rough idle) and had CELs. So, I hooked it up to a OBD II reader and it threw 4 codes: P0171 (Bank 1 System Too Lean), P0174 (Bank 2 System Too Lean), P0302 (Cylinder 2 Misfire), and P0307 (Cylinder 7 Misfire). I found the vacuum leak and I'm 90% sure that is why I'm getting the first 2 codes, what I'm concerned with are the 2 misfiring cylinders. I took the COP off of cylinder 2 and tested it with an ohmmeter like it listed in the Haynes manual (.55 ohms across the two connections on the top of the COP) and it passed that test. Next step is checking the spark plugs. Any thoughts on what else could cause these 2 cylinders to misfire consistently? Or could the coil still be bad even if it is within specs for resistance?
Cylinder misfire #2 & 7
- Thread starter zets101
- Start date
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walnuts4x4
Full Access Members
I know the COPs are very tricky little buggers... when was the last time a full tune up was done COPs and plugs? If you need good COPs cheap look on ebay for UNEEK or GlobalAutomotive.... both sell sets of 8 shipped for under 100 bucks and for plugs I would only use motorcraft or autolite double platinum... other plugs have been known to cause many problems like misfires....
walnuts4x4
Full Access Members
worse case pull out one plug and see what brand because these motors are very picky.. also check to see the condition of the plugs...
Turns out they did replace the plugs. They are Bosch platinum plus plugs, and they are in very good condition. I've read in some sources that the Bosch Platinums cause issues in V8 engines and in these Triton engines. Do you think they could be the culprit of my misfires? Anyone have any experience with Bosch Platinums causing issues for their Triton?
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walnuts4x4
Full Access Members
I had them in my old f150... big mistake... many problems... I would go with motorcraft or autolite double platinums.... both can be bought at autozone for fairly cheap.. but I'm fairly certain that those plugs are causing the problems... also you can get good deals on plugs from rockauto.com
autolite - APP103
motorcraft - SP-479
autolite - APP103
motorcraft - SP-479
walnuts4x4
Full Access Members
I have the autolite APP103 in mine for over a year now and they have had no problems
Coils & Plugs
Well I bought a set of 8 coils and autolite copper core spark plugs. I figured I'd keep it simple with the coppers as I'm trying to get rid of a misfire. I'll let you know how it goes after I install them and fire her up. Thanks for the input walnuts and you have a nice looking rig btw.
Well I bought a set of 8 coils and autolite copper core spark plugs. I figured I'd keep it simple with the coppers as I'm trying to get rid of a misfire. I'll let you know how it goes after I install them and fire her up. Thanks for the input walnuts and you have a nice looking rig btw.
walnuts4x4
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thanks and when you change the the plugs make sure you torq the plugs to spec... I believe 28ft/lbs... too much or too little contributes to the famous "plug spitting"... we only have 3 threads on our heads for the plugs
walnuts4x4
Full Access Members
also no anti-seize....
Don't use anti-seize? I thought everyone recommended it. Well, I found that in cylinder #7 the shop the previous owners took it to didn't feel like changing that plug. It still had an old rusty burned out Motorcraft plug. The shop probably felt that working around the fuel pressure regulator was too much work and the owners can go eff themselves. Yet another reason why I can't bring myself to trust a shop. If you want it done right, you have to do it yourself. Also upon inspecting all the other plugs that were actually changed (the bosch platinums) I see that they were burning too hot. Hopefully I'll have her all buttoned up by tomorrow and I can finally take her for a drive since I bought it. 
walnuts4x4
Full Access Members
from what I have read.... tons of sites...lol.... the common idea was without anti-seize the plugs were less likely to loosen up and cause the blow out... was also originally a torque spec of 14ft/lbs with anti-seize but later changed to the 28ft/lbs without... was less likely for the plugs to loosen and blow...
thats crazy about the old plug.... glad I helped (really watched) a friend change mine... also a member of this site DGray69... and if you haven't seen the other site http://fordexpeditionforum.com/ we are gonna combine that one and this one... many members are on both and the merger should be soon....
thats crazy about the old plug.... glad I helped (really watched) a friend change mine... also a member of this site DGray69... and if you haven't seen the other site http://fordexpeditionforum.com/ we are gonna combine that one and this one... many members are on both and the merger should be soon....
That makes sense about not using anti-seize, I'm glad you said something because I was going to use it. On the other topic: yeah I've seen the other forum and I've joined that one too just haven't posted there yet. After I get my expedition rolling I'll clean it up and get pictures of it on here and the story behind it. I'm learning a lot about these tritons and I'm not sure if that is a good thing or a bad thing lol. Hopefully I'll have enough knowledge to help someone else down the road.
walnuts4x4
Full Access Members
hope everything works out for ya... and some good people on here that have a lot more knowledge than I do... thats why I am hoping for the merger soon so we can get everyone on one page
rburch
Full Access Members
i have done alot of work on the modular engines and in my experience i have noticed that not using anti-seize causes the threads of the head to get stuck to the plug and when you remove them it strips the threads from the head. i have always used anti-seize even (on my own) and have never had the plug spitting issue.
i have done 3 plug changes on my expy with no problems at all.
i have done 3 plug changes on my expy with no problems at all.
Well, I finally finished the plugs and coils, and it fixed my misfires. It turns out only 2 out of 8 plugs were changed from the previous owner. The hardest part of changing the plugs and coils were cylinders #3&4 because of the heater hoses that go into the firewall. I wonder if anyone has a trick to working around the heater hoses for the next time I do it? I read a few write-ups on it and not once do they mention those evil hoses !
!Lcarvone
New Member
Are these examples of the ones you are referring to?
GlobalAutomotive
I have having a similar issue on my first Expedition (2003 EB with 5.4L) and am thinking about purchasing the COP's and plugs myself to take to the mechanic. I am more or less a novice to this type work and I assume it is better to change all at the same time versus piecemeal as they go bad...?
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walnuts4x4
Full Access Members
yes those are the COPs that I used from global... they also have a good customer service...
walnuts4x4
Full Access Members
Well, I finally finished the plugs and coils, and it fixed my misfires. It turns out only 2 out of 8 plugs were changed from the previous owner. The hardest part of changing the plugs and coils were cylinders #3&4 because of the heater hoses that go into the firewall. I wonder if anyone has a trick to working around the heater hoses for the next time I do it? I read a few write-ups on it and not once do they mention those evil hoses
easiest way... add a body lift...lol... body lifts off frame 3" and 3" of more room above the engine...lol but when we changed mine I held the hoses up while my buddy changed the plugs... glad you got it fixed
juanito198118
New Member
helllo i own a 1998 expedition at this moment i have a cylinder #2 and 7 misfire with P0174 code. she was running fine yesterday morning. went to the store shut it off when i went back into it. it was misfire plug in my scanner said at the time cylinder 2 misfire drove it home and scaned it again and it came out cylinder 2 and 7 misfire and the p0174 system too lean i need help...
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