misfiring in boost only now

[hillman]

before i changed the spark plugs, it was misfiring all the time. idling, acceleration, under boost really bad, and everywhere in between. now that i changed them out, it idles and accelerates great, but right when i get into boost, it still misfires. its definitely not as bad as it used to be when the old spark plugs where in there during boost, but i can still tell there is a missfire. any help would be great, i want to get this done by the end of the week since im on spring break.

[hillman]

and also, a week before it started misfiring, i put a 180 tstat in. the old one was sticking, but it was 160. i had it put it in when i got the pulley swap and everything. would this cause any of the misfiring?

[tiffo60]

sounds like spark blow out, what did you gap them at? TR6's? Should be gapped around .032

[hillman]

i put the br7's in b/c thats what the shop put in when i got my pulley swapped. i tried to gap them as close to .032 as i could get them, which is what the old ones where gapped at when i pulled them out.

[tiffo60]

if you just have a pulley thats really too cold of a plug(I was at 500hp with TR6's), I dont if its cold enough to cause your problems, but maybe someone else will chime in..

[hillman]

mods are: 6 pounder, cai, ftvb, and a tune
i took it out again and put some more gas in and now it seems to be misfiring, i guess you would say intermittently, from about 1-4 pounds of boost. anything after about 6 it just misfires. although, again, its not as bad of a missfire as it used to be. perhaps there might be some bad gas? i just thought i was done with it when i started it up and it wasnt shaking anymore.:hammer:

[dboat]

mods are: 6 pounder, cai, ftvb, and a tune
i took it out again and put some more gas in and now it seems to be misfiring, i guess you would say intermittently, from about 1-4 pounds of boost. anything after about 6 it just misfires. although, again, its not as bad of a missfire as it used to be. perhaps there might be some bad gas? i just thought i was done with it when i started it up and it wasnt shaking anymore.:hammer:

how old is the gas in it?

[hillman]

well it started misfiring the day after i put some gas in. at that gas station (this was about 2 weeks ago) it took like 5 minutes to put 3 gallons of gas in, but i really needed some gas and that was the closest station, so i think i got the oldest of the gas. but the gas thats in there right now, i got at college station about 2 days ago, and now i just added another 1/4 tank in there today. i think im gonna put some seafoam in there, maybe an injector is clogged a little and that will clear it up.

[BC Lightning]

my guess is the BR7's, mine never ran right with them in there

[joshc_guitar]

I have a buddy haveing the same problem with TR6s gaped at .034 and he has more mods than U. He's bringing it to the shop tomorrow to make them correct it b/c it didn't do it before they changed his plugs. So I will let you know what they did.

[L8 APEX]

Are the coils dry, maybe you got coolant in them when you changed the stat? Either the coil pack or plug. Anything under a 40 gap should fire on boost only.

[hillman]

yup the coils are dry. i changed the t-stat about 3 weeks ago. and did the spark plugs yesterday which were a pita. do you think a injector could be clogged a little? how could i check the coils when it idles perfect?

[joshc_guitar]

any codes? CEL?

[96mystic]

I have a buddy haveing the same problem with TR6s gaped at .034 and he has more mods than U. He's bringing it to the shop tomorrow to make them correct it b/c it didn't do it before they changed his plugs. So I will let you know what they did.
That would be me...I think I have a coil going out, or its not able to produce enough spark at higher RPM. I just changed my plugs, and I'm going to change my fuel filter, you never know, if could be the simplest of things. PLus it couldn't hurt it. If it's throwing a CEL then all the better (in a sense of diagnosing it) Good luck, I'll let you know what I find out. But I was having the same issue as you are, check the gaps on the plugs. Unplug your coil packs one by one, and see if you hear a misfire or a change in exhaust note, its what you want to hear. If nothing happens when you disconnect that coil then it could be a bad one. Hope this helps you out.

[In2deep]

Thermo is to cold 180 is sufficient and .34 is the correct gap, a coil could be out or maybe u did not tighten down a plug good enough!!

[hillman]

any codes? CEL?
nope nothing


That would be me...I think I have a coil going out, or its not able to produce enough spark at higher RPM. I just changed my plugs, and I'm going to change my fuel filter, you never know, if could be the simplest of things. PLus it couldn't hurt it. If it's throwing a CEL then all the better (in a sense of diagnosing it) Good luck, I'll let you know what I find out. But I was having the same issue as you are, check the gaps on the plugs. Unplug your coil packs one by one, and see if you hear a misfire or a change in exhaust note, its what you want to hear. If nothing happens when you disconnect that coil then it could be a bad one. Hope this helps you out.
hmmm if its idling like it should be, then wont each one that i take out create the same tone since it idles perfect? even if i had somebody rev it when i took it out, idk if that would work either since it only happens under boost. i also changed the fuel filter too. is yours only misfiring under boost too? deff let me know what you find out.


Thermo is to cold 180 is sufficient and .34 is the correct gap, a coil could be out or maybe u did not tighten down a plug good enough!!
each plug is at 13lbs. and i gapped them as close to .032 as i could get. i could only find a feeler guage that went from .032 to .035. i made sure the .035 couldnt fit but the .032 could.

so what would you guys do? does ford have some kind of computer that can say which cylinder is causing it? or get a new coil pack and swap it out with a old one, take it for a spin, and repeat until i find it? geez that would suck:crying:

[96mystic]

nope nothing


hmmm if its idling like it should be, then wont each one that i take out create the same tone since it idles perfect? even if i had somebody rev it when i took it out, idk if that would work either since it only happens under boost. i also changed the fuel filter too. is yours only misfiring under boost too? deff let me know what you find out.


each plug is at 13lbs. and i gapped them as close to .032 as i could get. i could only find a feeler guage that went from .032 to .035. i made sure the .035 couldnt fit but the .032 could.

so what would you guys do? does ford have some kind of computer that can say which cylinder is causing it? or get a new coil pack and swap it out with a old one, take it for a spin, and repeat until i find it? geez that would suck:crying:
all you have to do is disconnect them from the harness individually, they will cause a misfire, therefore creating a different tone. (kinda like idleing weird) Yes mine only does it after 10lbs or so, I'm thinking that one of the boots is allowing spark to travel through and slightly send spark somewhere else, or maybe a coil is just giving out.

[hillman]

all you have to do is disconnect them from the harness individually, they will cause a misfire, therefore creating a different tone. (kinda like idleing weird) Yes mine only does it after 10lbs or so, I'm thinking that one of the boots is allowing spark to travel through and slightly send spark somewhere else, or maybe a coil is just giving out.
ya i unplugged the first three on each side and all 6 did the same thing. after about 5 seconds the rpms would drop to about 600. i was too lazy and the truck was too hot to get to the last two. ill get to those tomorrow. but since it is idling like it should be, without any problems, wouldnt i have the same result from each of them? its weird we have the same problem at the same time....

[99WhiteBeast]

yup the coils are dry. i changed the t-stat about 3 weeks ago. and did the spark plugs yesterday which were a pita. do you think a injector could be clogged a little? how could i check the coils when it idles perfect?

Are you sure you have everything connected right? I've seen some strange things after a plug change when an injector or coil pack connector was not firmly seated. I always made sure to turn down the radio in the garage so I could hear that positive click of the connectors.-Just a thought.

[hillman]

Are you sure you have everything connected right? I've seen some strange things after a plug change when an injector or coil pack connector was not firmly seated. I always made sure to turn down the radio in the garage so I could hear that positive click of the connectors.-Just a thought.
im gonna triple check that tomorrow too lol. i think i might redo the last COPs on each side too, make sure theyre in all the way. although if they werent i dont think i would be able to bolt them in all the way...

[joshc_guitar]

nope nothing


hmmm if its idling like it should be, then wont each one that i take out create the same tone since it idles perfect? even if i had somebody rev it when i took it out, idk if that would work either since it only happens under boost. i also changed the fuel filter too. is yours only misfiring under boost too? deff let me know what you find out.


each plug is at 13lbs. and i gapped them as close to .032 as i could get. i could only find a feeler guage that went from .032 to .035. i made sure the .035 couldnt fit but the .032 could.

so what would you guys do? does ford have some kind of computer that can say which cylinder is causing it? or get a new coil pack and swap it out with a old one, take it for a spin, and repeat until i find it? geez that would suck:crying:

Some shops will have the computer you're thinking of. It's called the "Brick". It's a little hand held device that views all possible parameters of the engine.

Edit: Said shops may charge to use it.

[99WhiteBeast]

You can get a coil tester to see if they are working-cool item:cool:
http://www.tooldiscounter.com/ItemDisplay.cfm?lookup=WAE76560

[hillman]

is there an auto parts store where i can get this miracle item lol

[99WhiteBeast]

is there an auto parts store where i can get this miracle item lol

maybe-I think you would have better luck at some automotive tool supply.

You could also flag down a SnapOn, MAC tool truck but expect to pay big bucks.

[hillman]

welllllll..... she runs like a champ again:burnout:. i took it to ford and they did their little diagnostic thing that said what cylinder is not working. the culprit was the #7 cop. bought a new one and put it in and everything is better now:banana:. thanks for all the help.