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i have a 99 f150 4x4, 4.6L w/128,000 mi. i hooked a timing light to the plug wires to check the plugs and not all of them sparked at the same speed.. some were faster than others. is this normal. if not, is it a plug problem? or wire or coil pack problem? or something else that i would rather not know about...i can notice that there is a small miss when at idle and can feel it under acceleration..if anyone has any ideas, lets hear them...thanks guys
i have a 99 f150 4x4, 4.6L w/128,000 mi. i hooked a timing light to the plug wires to check the plugs and not all of them sparked at the same speed.. some were faster than others. is this normal. if not, is it a plug problem? or wire or coil pack problem? or something else that i would rather not know about...i can notice that there is a small miss when at idle and can feel it under acceleration..if anyone has any ideas, lets hear them...thanks guys
Since your thread is on page three with no response let me take a crack at this. What I think is happening is the plug wires are leaking. You say they are firing at different speeds? I believe you mean one or two plugs are firing twice when they should have fired only once.
This sounds like the insulation on the wires may be cracked and the voltage is jumping from one wire to the next causing a misfire. Just my uneducated guess.
I would question if your timing lite is fireing reliably first.
Some lites don't work right on some systems. Yous is a waist spark ignition.
I have seen top of the line Snap-Ons not work on MSD systems where my low end Sears Craftsman will.
In fact, it will trigger off the primary leads to the coil on a COP system and can check timing on a 4.6. There are even timing marks to check with.
Something to look at as a possible reason before deciding there is a problem..
I would question if your timing lite is fireing reliably first.
Some lites don't work right on some systems. Yous is a waist spark ignition.
I have seen top of the line Snap-Ons not work on MSD systems where my low end Sears Craftsman will.
In fact, it will trigger off the primary leads to the coil on a COP system and can check timing on a 4.6. There are even timing marks to check with.
Something to look at as a possible reason before deciding there is a problem..
Good information concerning timing lights but you forgot cneagle87 stated in his original post he can feel the misfiring while driving the truck.
If the..truck..has not had plugs and wires, it would be a good tuneup to put them in.
The..boots..get and old and can crack from drying up.
Use di-electric grease inside the ends of the new boots so they seal to the plugs and make it easy for the boots to slip on and seat.
Change them out one at a time so you keep track of where the plug wires go on the coils.
The miss you see will probably go away provideing the coils are fault free.
Then address problems that may be left.
Last edited by Bluegrass 7; Dec 12, 2006 at 09:06 AM.
i appreciate the advice bluegrass, but the thing that has me confused is the plugs and wires are less than two years old...so, that is why i am thinking that the problem goes a little deeper..
Well, best I can do for you. You have to start somwhere.
I have experience with this and a lenghty investigation has revealed some interesting things.
I have tested different plug makes, special insulation tecnques that keep moisture out, coil resistances, plug resistances, boot faults etc. But not ready to release any info unless some one really wants the help because it is subject to to much controversey by prople that have not done any investigations but have lots of opinions..
I have seen factory OEM plugs fail in less than 1000 miles so there is a lot going on besides just banking on plugs and wires that have low mileage on them.
Without some effort, the problems don't go away by themselves.
I don't pretend to know what problems you have but
Good luck.
Last edited by Bluegrass 7; Dec 12, 2006 at 06:45 PM.
Well, best I can do for you. You have to start somwhere.
I have experience with this and a lenghty investigation has revealed some interesting things.
I have tested different plug makes, special insulation tecnques that keep moisture out, coil resistances, plug resistances, boot faults etc. But not ready to release any info unless some one really wants the help because it is subject to to much controversey by prople that have not done any investigations but have lots of opinions..
I have seen factory OEM plugs fail in less than 1000 miles so there is a lot going on besides just banking on plugs and wires that have low mileage on them.
Without some effort, the problems don't go away by themselves.
I don't pretend to know what problems you have but
Good luck.
i did not mean to be disrepectful Bluegrass. i just didnt state earlier in the post the age of the wires and plugs. thinking that it may make a difference in your opinion..again, no disrespect intended..so, do you think that i should start with OEM plugs and wires?? Then Coil packs if need be? Is this the starting point, then go from there???
Don't worry about it. I have to go with whatever your position is.
Try plugs first. A low cost plug is the BOSCH #6241. A single plat that work fine. Nothing fancy. I run them without a problem.
Pay close atttention to boot seal and condition. If the boots are enlarged and not a snugg fit, leakage to the body can result as well as moisture getting inside the top seal area.
Speaking of the boot seal..i discovered last week that the heater hose above the plug next to the fire wall on the passenger side was leaking.. it leaked right on top of the plug, so i changed the plug.. and the plug had antifreeze on it and the wire boot did as well.. i used compressed air to clean the boot as best i could and used air in the plug well too..now after replacing the plug and cleaning the boot and well, could there still be a problem here?? do i need to replace the wire??
and you mentioned the bosch plugs. so these work just as fine as motorcraft? i've just heard alot of different things on these post about brands of plugs....
and you mentioned the bosch plugs. so these work just as fine as motorcraft? i've just heard alot of different things on these post about brands of plugs
I've heard a lot as well. Every parts store I checked said use only motorcraft or autolite plugs. Personally, I would stay away from Bosch, because I've been told by numerous people to use only OEM or autolite (here and at least 4 parts stores). Ultimately the choice is yours though.
Must be some sort of conspiracy against bosch out there then, The guys at advanced auto, auto zone, pep boys and the small local shop I usually get my parts at all told me the same thing without me even asking them which brand I sould use. The girl at the autozone looking it up probably would have sold me bosch until the manager at the terminal next to her said autolite or motorcraft only.