No, don't worry about pins 13 and 14. It's tough when it's intermittant and not throwing a fault code. Do you have a stethoscope to listen to the injectors firing? I'd guess it's spark just because of timing. I'm scared to put anything but Bosch F8DC4s in the car but that may be an irrational fear. These things - http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=36258 - are nice for checking spark if you're close to a Harbor Freight. They also have cheap stethoscopes.

Could be a loose spark plug connector, or maybe a connector that is starting to go. An ohm meter with long probes would be handy to have.

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It is a truism that almost any sect, cult, or religion will legislate its creed into law if it acquires the political power to do so. Robert A. Heinlein


09 Jetta TDI
1985 300D

Well, this weekend I found the source of the heavy engine missing. (Loose spark plug connector...wasn't seated in all the way ) Now comes the issue with how the engine performs under heavy acceleration. The engine lags and gives a jerking motion from missing. At idle it's dead quiet and when revved up in Neutral is perfect as well. It's only when the engine is under stress from the transmission. The only thing that I can think of is that the Techron that's currently running through the system is causing it. Has anyone had any similar symptoms? (I still have NGK plugs in as well)

Keep me posted!

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1995 E420
1998 SL500 Sport
2009 E350 Sport
1995 S500 Coupe
1992 500 SEL

I'm also considering widening the spark plug gap on the NGKs to around 1mm to help smooth out the idle. Is there a major caveat to this?

Found the culprit for the heavy missing this weekend. (Loose spark plugs (2)...gaskets weren't crushed all the way so two of them were loose..Lesson learned: Triple check everything when you're doing plug wires, caps and rotors because there's a lot of crap going on there and it's easy to space out on something. Kind of embarrassing if you ask me )

Now comes the question posed earlier about stabilizing the idle a little bit more. In the morning the car DOES still idle rough (sometimes it can even miss) and I'm considering widening the gap on the spark plugs. (0.9mm vs 0.8mm). Do the ignition coils on the 119 have enough juice to support this and would this resolve this issue? (Techron has been run through the system already so the injectors should be fairly cleaned out)

Keep me posted.

Carefully inspect all sparkplugs for cracked insulators,They are hard to see but will give you fits!
Wrong wrench or improper tightening can crack the insulator.
Mike

If you're spending that much with the pkugs...scrap them...get the OE Bosch Supers.

Plugs swapped out for the OE Bosch Supers. Car ran flawless for about 20 min. then dropped back into the missing cycle again. Now I'm dreading that something got disturbed with the wiring harness throughout the process of replacing the plugs and wires .

As of now, plan A is to double check all of the vacuum lines to ensure that nothing is screwy there. If that checks out then it's time to inspect the wiring harness in further detail. I'm planning on posting pictures of the areas of concern (wiring harness exposure areas in the engine compartment) to see if anyone can help to provide me with some insight to the problem. (I've read all of the posts so I know which areas to closely inspect)

With the car's history of roasting in the southern Texas heat for 13 years, I wouldn't be surprised if this was the cause of my problems.

Definitely keeping everyone posted...

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1995 E420
1998 SL500 Sport
2009 E350 Sport
1995 S500 Coupe
1992 500 SEL