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View Full Version : i really need some help before waterfest



king
07-12-2010, 08:14 PM
Ok I have a 2.8 12v lately I've been having random misfires on pitsons 3 and 5. After changing. Myplugs abd wires the problem never went away. Then today my friend and I were taking a look at my coil pack and the car started running like crap out of nowhere. Tomarro I was goin to get a new coil pack but I wanted to know if its actually rhe coil pack ir if somthing else is causing the misfires. I really need to get this done before Friday so if some one could help me that would be great. Thanks

king
07-13-2010, 04:19 AM
Anyone??

turbo_bootin
07-13-2010, 04:27 AM
Try switching the coilpacks around and see if the misfires follow.

king
07-13-2010, 07:14 AM
I tried that and when I did its started running even worse

somebody5788
07-13-2010, 07:57 AM
How are we supposed to know if its your coils? It could be that or the plugs could be wrong or it could be your MAF or a bad injector or 2 or even bad gas. There are soooo many reasons your car could misfire.........

There are proper steps to take to test parts. If you are excluding plugs and wires due to replacement then your next logical step is to test the spark output of the coil. You need a spark tester.

Daft
07-13-2010, 08:24 AM
I tried that and when I did its started running even worse

Since you have a 12v 2.8, you only have one main coilpack. (it is segmented into two halfs N128 & N158 but, they are specifically wired to fire specific cylinders) You cannot just move the plug wires around as this will just create more misfires.

http://www.daftsgarage.com/diagrams/AFC_coilpack.jpg

Here's what you need to do.

#1. Figure out what cylinder has the initial problem. Disconnect one plug wire at a time until you disconnect one that does not cause the motor to run worse. This will tell you which one is the issue.
#2. Check that plug wire and the spark plug for issues. (cracked wire, loose connectors, fouled plug, loose connector at top of plug, etc..)
#3. If everything looks ok, you can try swapping out that plug wire for another one. Do not change the positioning, fully remove a non-problematic plug wire and use it at that position just to see if anything improves. If not, you may have a coil issue.

Please bear in mind that you also have a power output stage that is connected to the coilpack (N122). If it has failed it usually will loose one portion of it's output. The only thing that makes me think that it isn't that is that the loss of one half of that output stage would probably cause 3 of the plugs to stop getting spark.

Start with the tests above and see what you can figure out first. You might also have a CEL related to the coils. It would be good to have a look and see what is there.

king
07-13-2010, 02:32 PM
Today I plugged up a code reader to the car abd it said that I have random misfires on cylinders 3 and 5. I checked all the plugs gap, I checked the wires for cracks and I looked to make shure everything had connection. I had my ol wires aswell and I swapped them out. The randpm misfires didn't go away

Urtorsen
07-13-2010, 05:27 PM
Please bear in mind that you also have a power output stage that is connected to the coilpack (N122). If it has failed it usually will loose one portion of it's output. The only thing that makes me think that it isn't that is that the loss of one half of that output stage would probably cause 3 of the plugs to stop getting spark.
id go with that being your problem...60 bucks to change but just buy it, keep the slip ,and try iit out.....and return it if it isnt doing the trick?

scottb2240
07-14-2010, 02:05 PM
im gonna have to say that its ur icm. I have a 1.8t but i had this same problem. esctuning has them for 140. if u do replace that make sure that u use thermal compound in order to prevent it from over heating.

brockallentaylo
07-14-2010, 04:10 PM
Probably the ICM, I usually take a piece of ground wire and ground it to the frame and pull off one spark plug wires at the coil, start it and note the maximum distance you can get the spark to jump over to your ground wire, put that plug wire back on the coil and move to the next. If you notice one cylinder has a weaker spark then it's probably the coil. If they seem roughly the same and can jump a 1in spark it's probably the ICM firing intermittently or something else. This is just the redneck way I would test it if I did not have the proper tools, make sure the ground wire is well insulated and that you hold it a good 8in back from the tip so you don't get the crap shocked out of you.

You can move the coils around but you have to cut and splice the wires going to the coils as there are no plugs on the wires to disconnect right in the front where the coils are on the 12v.

If you need a coil I think I have 2 off of a 12v. PM me.

Also make sure your connections at the ICM on the top of the air filter housing are not corroded.