Misfiring Again..already

[SLOW98NB]

As the title states only 2 weeks and 1200 miles later since i replaced all 4 coil packs it started misfiring progressivly worse on the way home 2day. CEL flashed once but for a lot longer than it had a few weeks ago when this first happened. I put Denso spark plugs in this past summer and pack just a few weeks ago. Is there anything i missed??? It only misfires when i get into the throttle 50% or more than 3-4 psi of boost. The first time it happened 2day was only at full boost then started happening more often and at less throttle. On a side note could it just be shotty fuel. I did fill up this morning at the same Sunoco I always do with 93. The problem started about 40 miles after that. Coincidence??? Who knows?
I will check connections and torque on the bolts as soon as the engine and myself cool off. I really don't want to see the dealer about this since its 30 miles in the opposite direction that I work in.
Sorry for the long rant post but your input is appreciated

[Too Cold NB1.8T]

The symptom(s) you describe could be the result of a number of causes (both fuel and electric), aside from scanning to identify what DTC's have been stored, I would take a good volt meter and check the output voltage at the alternator terminals as well as at the battery terminals.

[SLOW98NB]

Originally Posted by Too Cold NB1.8T

The symptom(s) you describe could be the result of a number of causes (both fuel and electric), aside from scanning to identify what DTC's have been stored, I would take a good volt meter and check the output voltage at the alternator terminals as well as at the battery terminals.

I do have a good meter but it's at work. Should be 14 volts?? Engine running or off? Where are the terminals on the alternator?? I was thinking the alternator and/or battery might not be up to par when my headlights have seemed dull lately. Maybe it's just me. I'll definitly check tommorow night tho.
Sad as it is I'm just considering taking it to the dealer since there are no constant cel's to go by and no VAG-COM user's closeby. If it is the alternator it looks like a pain to change out anyway. It's funny how good the car ran since i changed the coil packs 2 weeks ago now only to have something else happen.
Thanks TooCold, if it wasn't for members like you on the site I prolly wouldn't still own a vw

[Too Cold NB1.8T]

You should first check the battery charge level with the engine and all accessories "off", then with the engine running, you want to carefully connect the volt meter + probe to the + output post on the Alternator and the -probe to a known good ground.

With the engine running, you want to also check the voltage output at the battery terminals, be sure that the meter is set to DCV measurement and don't forget to write down the results of each of the three tests.

With a fully charged battery you should see about 12.5 volts at the battery with everything "off", with the engine running you should see about 13.5 volts to around 14 volts depending on alternator temperature.

You are very welcome SLOW98NB, I hope this isn't anything serious, keep us posted.

[zeusenergy]

Originally Posted by SLOW98NB

As the title states only 2 weeks and 1200 miles later since i replaced all 4 coil packs it started misfiring progressivly worse on the way home 2day. CEL flashed once but for a lot longer than it had a few weeks ago when this first happened. I put Denso spark plugs in this past summer and pack just a few weeks ago. Is there anything i missed??? It only misfires when i get into the throttle 50% or more than 3-4 psi of boost. The first time it happened 2day was only at full boost then started happening more often and at less throttle. On a side note could it just be shotty fuel. I did fill up this morning at the same Sunoco I always do with 93. The problem started about 40 miles after that. Coincidence??? Who knows?
I will check connections and torque on the bolts as soon as the engine and myself cool off. I really don't want to see the dealer about this since its 30 miles in the opposite direction that I work in.
Sorry for the long rant post but your input is appreciated

You're in PA, so that means some cold temps and nasty roads during the winter. I'd double check the coil pack harness and make sure there are ZERO cracks in any of the wires and make sure the ground connection is in good shape, maybe even take that bolt off and look under it for corrosion. It's a quick fix that may help your problem if the alt/battery is fine. You can get a new harness to replace that one, it's a job but from what I hear most people can handle it.

[SLOW98NB]

I pulled all the COP's and plugs. One plug is MISSING a center electrode but must still be firing enough to run ok with no boost. I hope it didn't affect the new pack in any way. You think running one different brand plug would have any performance issue's. I will check the A/A auto and Auto Zone on my home tommorow to see about getting a new Denso IK20.
As for the alt/batt issue. I'll check that anyway seeing as how she's got 123500 miles already. Both are Bosch parts.
Thanks for the help and I'll keep you posted

[SLOW98NB]

Originally Posted by zeusenergy

You're in PA, so that means some cold temps and nasty roads during the winter. I'd double check the coil pack harness and make sure there are ZERO cracks in any of the wires and make sure the ground connection is in good shape, maybe even take that bolt off and look under it for corrosion. It's a quick fix that may help your problem if the alt/battery is fine. You can get a new harness to replace that one, it's a job but from what I hear most people can handle it.

I like quick fixes^^ but the harnesses look good

[sb_beetle]

Originally Posted by SLOW98NB

I like quick fixes^^ but the harnesses look good

Make sure the plugs have the proper torque. Too loose and coils will start popping, plugs will start burning odd, etc, etc. Just speaking from experience :-)

[SLOW98NB]

1 New Denso IK20 - $14.00
The feeling of having your car running like a champ again - priceless

Also a round trip to work costs $20 in my truck or $10 in the NB. My wallet is glad to be able to drive the NB again