Funmart6
my name is mud
If you have an engine miss/stutter due to possibly a bad coil, how do you test the coils to find which one(s) is causing the problem?
How Do You Test Coils?
- Thread starter Funmart6
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NebraskaSHO
Harumph!
Buy a new one from AZ, AAP, or Ford.
Take off front vanity cover and replace one old coil with the new one at a time. If miss continues, replace old coil to original position, and install new coil in another's place. Repeat.
If it still misses after checking each front (5-8) coils, then drive it until the SES light starts blinking. This may take a while...
Another option is to buy 4 new coils, replace back coils with new ones, and to change rear plugs at the same time. Also allows you to clean intake and lower butterflies (if they are still in place). If miss continues, try the tip earlier in my post.
My .02
Take off front vanity cover and replace one old coil with the new one at a time. If miss continues, replace old coil to original position, and install new coil in another's place. Repeat.
If it still misses after checking each front (5-8) coils, then drive it until the SES light starts blinking. This may take a while...
Another option is to buy 4 new coils, replace back coils with new ones, and to change rear plugs at the same time. Also allows you to clean intake and lower butterflies (if they are still in place). If miss continues, try the tip earlier in my post.
My .02
midnightauto
THE CHOP SHOP
pull the vanity cover start the engine unplug one coil at a time see if the miss gets worse if it does the coil is firing move on the next one. you can not do this to the back but you can unplug the back 4 injector's one at a time it will have the same effect. whatever cylinder does not make the car run worse is the culprit. best if done with engine at operating temp.
nothingtoseehere
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As was mentioned, unplug one front coil at a time. If this does not reveal the culprit, swap the front to the rear and do the same thing. Also, while the intake is apart, inspect the wires going to each coil in the rear. I had one that needed re-insulating against the heat as it began melting through the wires ... repaired that and I have no more misses
Funmart6
my name is mud
Thanks for the tips, how do you unplug the injectors for the rear? I just wonder if this will work, my engine skip doesn't occur until the engine has warmed up, usually idling at a stop light.
So I should probably drive around until it starts to skip then let it idle and do the injector thing.
So I should probably drive around until it starts to skip then let it idle and do the injector thing.
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midnightauto
THE CHOP SHOP
Long fingers... you can get too them most of the time with one finger on each side of a intake runner to depress the clips and they pop right up. A 99 is even easier but your then pulling the plenum anyway to fix the dumb a$$ clips that break.
You can wait for the check engine light and just have it scanned
Funmart6
my name is mud
My SES light is on now. I had it scanned once at Autozone, but their scanner didn't display a code for a coil, that was some time ago. The tranny guy that rebuilt my trans said it was showing a code for the IMRC, but I knew that because the box had gotten plugged back up when they put the trans back in. They had the engine cover off in order to get to the exhaust guards and manifold I guess, (I unplugged the box and wired the secondaries open several months ago). Anyway, I will have it scanned again.
Thanks Ray
Thanks Ray
ThatShoGuy
SHO Member
this is what im gonna try
check all the fronts by unpluging them and pluging it in then if they all test good (i got 4 other good ones from a yard car) im gonna move the fronts to the rears (hope the heat dont **** them and then if one from the back was dieing it will now be in the front...
check all the fronts by unpluging them and pluging it in then if they all test good (i got 4 other good ones from a yard car) im gonna move the fronts to the rears (hope the heat dont **** them and then if one from the back was dieing it will now be in the front...
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MYSHO1
PiCkLe DaNcE!
Put the coil on the ground, and get on a table and jump on it... of your feet touch the ground with the coils under its not good... if it send you flying they are good.... oh ya get a video of it to...
NebraskaSHO
Harumph!
Mysho1
j/k :laugh_ti:
The light should blink, that's how long it had to go until it threw a code. Should be P030x (x = 1-8) I think...
j/k :laugh_ti:
The light should blink, that's how long it had to go until it threw a code. Should be P030x (x = 1-8) I think...
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Funmart6
my name is mud
Okay, I just finished. I unplugged the coils one at a time on the front of the engine. As I unplugged them, the engine would die down a little, then when I would plug them back up the engine would run normal. I also unplugged the injectors one at a time with the same result. I did have one coil on the front, the one closest to the battery that when I unplugged it, it didn't have as much difference as the rest, wonder if this one could be the culprit. I don't think I could get that lucky.
If all the coils were okay and the engine skip was still there, what should be checked next? Could the rear wiring harness be causing the skip? Could it be that the plugs just need to be replaced?
If all the coils were okay and the engine skip was still there, what should be checked next? Could the rear wiring harness be causing the skip? Could it be that the plugs just need to be replaced?
midnightauto
THE CHOP SHOP
You just did the poor mans power balance test. I would flop in a new coil on the week cylinder you found. the coil may still be working a little but is on it's way out. you can flop it with another up front to see if the change follows the suspect coil. I would not over think the problem coils are a common failure. (I carry 2 in the trunk)
ThatShoGuy
SHO Member
carry 2 in the trunk huh lol thats funny i got 4 spares but dont carry them
if they go bad its not like i can really change them on the side of the road...
nothingtoseehere
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carry 2 in the trunk huh lol thats funny i got 4 spares but dont carry them
if they go bad its not like i can really change them on the side of the road...
Sure you can. Basic hand tools get the vanity cover off, and basic hand tools can get the surge tank off as well. I have one in my center console.
ThatShoGuy
SHO Member
if you wanna do all the work on the side of the road tho lol i know its possiable
anyways i do that poor mans balance test because my car has a miss feeling.. and in OD at about 2300rpms it shutters really badly but not all the time . i really really doute it being the trans its been rebuilt and has maybe 5,000miles on it (but it did get rebuilt like 3 years ago..)
what i did was pulled the coil plugs in the front let it run like that for a few sec's, then for all 4 rears i pulled the injecter plugs (which wasnt to bad) and i didnt really get any diff in the way she's running besides one for the injecter had a very very slight change in it (i beleave its #4 cyc) back closet to the trans...
im thinking i got a vac leak also because my intake might not be sealed that well i had this spray gasket shit that came with my gasket kit from b4 and i reused it put it on the old gaskets and reused them. well i think they didnt seal well and have some leaks
idk if im just gonna rtv them with no gaskets or rtv on the gaskets what do you guys think..
ThatShoGuy
SHO Member
well i think i figured out my shutter in od one coil had a very weak spark changed it out so far so good..
Funmart6
my name is mud
I remember (it has been over a year ago & it is posted on here somewhere), I changed my coils around on the front (not new ones just moved them), after I moved them, I had all kinds of shifting problems, of all things. I would leave from a stop light and when the trans would try to shift into second, it wouldn't shift and when I would hit the gas, the engine would rev and fall, like it was on the rev limiter. It was strange. I would pull over, shut the car off, crank it back up and everything would be normal again. Someone on here said it was a bad coil making an interference with the shift module or something like that. Sounded weird, I moved the coils back to their original locations and the problem has never occurred again. Anyone ever have weird things like this happen from just moving coils around?
Maybe this is related also, maybe not.
Something else that I have going on. When the engine studders/skips, if the a/c is on sometimes it will kick the compressor off and I won't have cool air anymore until I cut the car off, turn it back on and it all works again. Also at night with the lights on, when the skip occurs, the lights will dim just a bit (interior and exterior), and also, my radar detector will chirp (it is hard wired into the fuse box) and the sub in the trunk will thump. Could a engine skip cause all of this? Or does it sound like toasted wires? I want to replace the weak coil that I found yesterday, but I just can't see all of this caused by a weak coil.
Maybe this is related also, maybe not.
Something else that I have going on. When the engine studders/skips, if the a/c is on sometimes it will kick the compressor off and I won't have cool air anymore until I cut the car off, turn it back on and it all works again. Also at night with the lights on, when the skip occurs, the lights will dim just a bit (interior and exterior), and also, my radar detector will chirp (it is hard wired into the fuse box) and the sub in the trunk will thump. Could a engine skip cause all of this? Or does it sound like toasted wires? I want to replace the weak coil that I found yesterday, but I just can't see all of this caused by a weak coil.
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NebraskaSHO
Harumph!
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midnightauto
THE CHOP SHOP
carry 2 in the trunk huh lol thats funny i got 4 spares but dont carry them
if they go bad its not like i can really change them on the side of the road...
FORD = Tool box in trunk
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