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f-150 4.6l 1998 miss?

alright guys i just bought my first newer style ford for 1700 bucks it has 235000 km on it dont know how many miles that is lol. had a miss changed plugs and wires was good for a while started to develope a miss when you hit a hill doing 60km or so and you try to lug it along in 4th g ear. had a tranny guy check it over he doesnt believe it to be trans he thinks engine. changed coil packs it went away for about 2 weeks then its back again only when you hit a hill. i am outta ideas i did do a injector service to it. tranny service i am out of ideas. o2 censor? cam sensor? crank sensor? it never does it long enough to give off a code so i dunno lol it doesnt do it while i am towing either. and i put what i believe to be a heavy load on such a small engine. 3 snowmobiles 500 lbs each atleast. so i am really looking for help because mechanics around here dont like us do it yourselfers :p any advice would be appreciated. and from what i know it cant be that many options left except for a standard trans computer in an auto trans truck. thanks again
 

blacksnapon

Moderator
Staff member
alright guys i just bought my first newer style ford for 1700 bucks it has 235000 km on it dont know how many miles that is lol. had a miss changed plugs and wires was good for a while started to develope a miss when you hit a hill doing 60km or so and you try to lug it along in 4th g ear. had a tranny guy check it over he doesnt believe it to be trans he thinks engine. changed coil packs it went away for about 2 weeks then its back again only when you hit a hill. i am outta ideas i did do a injector service to it. tranny service i am out of ideas. o2 censor? cam sensor? crank sensor? it never does it long enough to give off a code so i dunno lol it doesnt do it while i am towing either. and i put what i believe to be a heavy load on such a small engine. 3 snowmobiles 500 lbs each atleast. so i am really looking for help because mechanics around here dont like us do it yourselfers :p any advice would be appreciated. and from what i know it cant be that many options left except for a standard trans computer in an auto trans truck. thanks again
Make sure there is no moisture getting in the "holes". I always use silicone dielectric compound on the inner part of the boots when changing plugs. This will prevent arcing to an extent, and assist in boot removal the next time you change plugs.
 

radialarm

Clown of Death!
smilieIagree smiliewhathesaid Except I put it on all electrical connectors.
 
thing is it was doing it before i did the tune up went away for a while did coil packs and its not even all the time now its only somtimes you hold it at around 60 and it will studder llike it loads up for a second but cleans out right away. it can do it some 3 times on a hill just studders stops studders stops its really weird. i am maybe thinkiing o2 sensor giving off wrong info havent checked to see how old it looks yet though will do that today
 
did flush the tranny but to no avail and the tranny guy said it didnt feel like torque converter chatter. i am at a loss. i was just out and its snowing so i wasin 4wd but it seemed to agrevate the miss m ore i dunno what eles it could be maybe a throttle positioning sensore? do they even have those. it just seems to be at certain points where you hold the throttle. like if i sit at an idle in park and slowly apply the pedal, stay at certain rpms on the way up what seems to be around 6 kinda has a shake to the enging or a miss. not a bad one or nothing but it is there? btw it was doing on flat ground while in 4wd this time its just odd to me. maybe the tranny is coming apart lol i dunno it does do good brake stands haha
 
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Sounds like coil packs to me I would do an ohms test on them just to make sure. A new one could be bad especially if aftermarket. If you do it yourself it doesn't cost anything but time. My 5.4 did this and after a week it finally threw a code # 8 cyl misfire
 

lil_dq

Let 'er eat boys!
6,933
265
Union, MO
Check your connections at the injectors, I know it sounds funny but, if your coils have all been replaced then I would run a scan on the puter, then check and see if it shows a miss. If it does then double check your injector plugs. I have had a plug loose on mine before and it stumbles like that. Also make sure that you don't have a crack right where the plug-in goes into the coil. I have found that little connector is a VERY weak spot on the coil. I will try and get some pics up tomorrow for ya. I just had to replace another coil yesterday due to this very issue. Luckily I bought lifetime warranty Borg Warners from Oreiley's! I never have to buy another coil again.
 
so as it seems my coil packs fried teh gel that goes in the boots of the wires to the plugs so my plugs are covered in black gunk and i went and put motocraft plugs back in (did 6 plugs already) and noticed a huge difference gonna do the other 2 and keep cleaning out the wires with some cleaner because it seemed to fix it for a couple days then its not near as bad and today it did it some more but not like before... should i take apart my mass air flow sensor and give it a good soaking and cleaning?
 

Bob Ayers

North Carolina Chapter member
1,474
111
Durham, NC
What kind of plugs did you replace the Motorcrafts with? If they were Bosch, that would explain your misfire problems. I went through the same thing with my Ranger when I bought it, the previous owner had installed Bosch! Bosch plugs and Ford's EDIS don't play well together........
 

d-kuzmen

Master Ford Tech
2,109
79
Connecticut
What kind of plugs did you replace the Motorcrafts with? If they were Bosch, that would explain your misfire problems. I went through the same thing with my Ranger when I bought it, the previous owner had installed Bosch! Bosch plugs and Ford's EDIS don't play well together........

Neither do Champion!
 
they were ngk at the time but now its got motocraft back in it and i am gonna take a closer look at my wires (ngk also) and maybe go pric e out new motocraft ones. because i somehow have a feeling the wires are burnt full of that dielectric grease stuff. i get pictures on tonight when i get home from work
 
alright another wquick question here. i kinda figured i would check the my wires to my injectors... not how tight are they supposed to be... not me spin them out by hand right? and do they spin in pop in or what. got me really thinking about this one. and the electronic conectors are pretty loose on them to .
 
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