ok i have a 99 f-150, 4.6l, 2wd. its parked outside overnight, everynight, i know go ahead and call me an *******, lol. anyways aftera night of heavy rains i start my truck up and it dosent rev as quickly, if at all, to 2k rpms like normal. and i think nothing of it but then i put it in drive and under heavy acceleration it misfires(feels like it but no service engine soon light, well yet) but at a moderate to light acceleration it feels fine, smooth as glass at idle, and after it runs at operating temp. it goes away. now i know that ppl are gonna say wires right away, well geuss again, lol, cuz i have sprayed water on the wires and watched for arcs but nothin, no suprise i knew this wouldnt be that easy, c'mon these trucks make ur brain smoke to diagnose em', lol. now for the first time on sunday the light came on after a day long of rain, checked it at work - "cyl #2 misfire detected" and when the light was on the misfire went away, but it still had the startin symtom, even when dry. cleared the code and now its back to normal. but im sick of this **** and wanna get rid of this problem from my head and not worry bout it after a night of rain or soon to be snow, any and all help will be greatly apprieciated
josh

 

Have you checked the #2 plug? How are the coils? If the wire is cracked inside it may not ark but it will cause the miss.

JMC

 

thanks, but if the wire is cracked inside the insulation wouldnt misfire when dry as well? same wit the plug. i'll have to look into the coil packs, i was thinkin of gettin the msd coil packs but they say it only works on 95-98? i called my parts store and checked wit them and they said its the same part #s for 97-99. wuts up wit that? here are those coil packs on truck performance.com - http://truckperformance.com/products/?productID=726975

 

Ok guys, the the few girls, i am bringin this one outta the crypt to update everyone here. i got so sick and tired of driving around and having a misfire in the engine so i got a set of motorcraft wires and a set of autolite double platinum plugs pcv and fuel filter. installed em all and it ran smoother than wut i thought was possible. took it on a trip to columbus in a thick snow and developed the miss agian! pulled over poped the hood and the k&n filter was covered wit snow. after a while more of driving and it still missing, traffic got real slow cuz it was 3 inches of snow on the highway. the miss just seemed to dissapear. it did trip the cel but it went away after days of not missing. after that i had no work done to it, but no porblems. i have recently installed msd coil packs, msd super conductor wires, nkg plugs and a msd dis-4 ignition. while installin the coil pack on the drivers side, i noticed a purple wire with a white tracer half assed spliced into one of the wires feeding the coil. i traced it to my remote starter i had done at best buy. i will have them re-connect it and water proof it better( it had a small amout of electrical tape and thats all!). i think that be a major reason problem for it cuz that coil feeds geuss wut cylinder? yep #2. i am kinda dissapointed here, almost 150 views and onle one person responds? and my other thread where i was askin for some help as well on installin my ignition got no replies. even if u have a jacobs ignition it wuda let me known that ppl carebout newbies, and are willin to let ppl know wuts goin on here. it is all good though this board has help many other members and im not one to jusdge on my randomized misfortunes.

 

In defence of the people here you have to understand that this board is composed of mostly shadetree mechanics.
Misfires are not easy to trace so not a lot respond. If I may suggest, adding your signature listing mods to your truck helps in knowing what could be wrong with the truck. Knowing that you had an aftermarket remote starter would have made it a lot easier. I should have asked but your profile lists your occupation as a mechanic so I did not. regardless your problem seems to be taken care of so alls well that ends well.

Regards

Jean Marc Chartier