Just a quick question. If there is an intermittent failure with the coil(s), injectors, ignition, or transmission locking and unlocking (maybe something with the torque converter,) will these problems show up when the codes are read?
My Grand Marquis is still bucking and skipping at all speeds and acceleration demands and NOTHING is showing via the computer. I would think that the error codes would come up and be saved, or whatever, but there is no indication at all that something is amiss.
Just wondering if these sort of symptoms and/or system failures would show up as an error code?
Thanks !
TC
panthers won't error code for JUST a misfire, most of the time. Only if the ECU thinks it knows why. I'd be inclined to check the ignition. mmmmmaybe check the EGR, but only after spark.
Ford has pretty much useless misfire detection from a code setting point of view. If whatever you are scanning with will show misfire counters, you may be able to test drive, and watch the counts build up on a particular cylinder.
If you don't have a good scanner, track it down this way: Take the retainer bolts out of all the coils, (I presume you are COP. If with wires, the same basic story applies, but you need to test continuity of the wires too.) put on your rubber gloves, idle the engine and lift each coil away from the plug. You should be able to hear the snap of the spark quite clearly, and you should be able to lift each coil 3/4 inch or so before the engine starts to miss. Don't do this for too long. If you hear a weak one, change it. If the idle doesn't change with one coil, but you can hear the snap, dig into compression and injectors, or look for a broken spark plug. If it doesn't show up a weak coil, and you have no miss at idle, pull the plugs and look for a carbon track on the ceramic where the coil boot covers it. If you see a carbon track, change that plug AND THE COIL, because the carbon track will be burnt into the boot as well, and it will run well for about 3 days, then start misfiring again.
Years ago my dad's truck (2001 F150 with a 5.4) had the same intermittent symptons on a road trip, and it turned out to be a coil pack. To me, it felt like the torque converetor was unlocking and locking, but it was a misfire. No CEL came on.
"To me, it felt like the torque converetor was unlocking and locking . . . "
EXACTLY ! ! And no check light as well.
I'm going to look into the coil packs, thanks guys ! I always thought that a skipping spark would turn up in an error code, nice to know that it doesn't and that I'm not going nuts or just imagining this problem.
Really, thank you ! !
This may not help you at all but my truck has been having random misfires without codes for a long time. When it gets bad it can just stall and not restart until it comes to a stop. This only happens between 3/4 and 1/4 full tank and is worse when driving level after climbing a large hill. It has a dizzy, so no coil pack problems. The next thing I am going to look for is a build up of nonburnable liquid in the gas tank from the mixture of ethanol.
chada75
New Reader
4/11/14 4:35 a.m.
My Crown Vic does what your are saying when in runs on 87 Octane. Make such you replace all 8 plugs at the same time as well.
When one of my Crown Vic's coils were failing, it was kicking hard on a heavy acceleration only. That was with one cylinder not firing. How many coils does that Grand Marquis have?
