I can't connect those dots at all.

 

I can't either. But in case my question made no rational sense... what i was trying to ask was in relation to your note about the 'wasted spark coils' and once side having some relation to the other.

I didn't think the dots would connect either, but that what i was trying to ask about.

 

My comment about wasted spark was to make the point that there are really 3 coils, and if one is bad it should affect a cyl on each side.


If you really want to play out your theory, soak all the oil out of the plug holes on the driver's side. I'm sure your gasket leak isn't bad enough that they're going to fill right back up in a day. See if it affects your miss.

 

Hi,

Received some awesome help from another forum member and did more testing (THANK YOU). We were able to rule out wires/plugs/coil/compression as possible problems. Also were able to determine that injectors were electrically functioning fine. We quit for the day feeling like my problem was probably due to a clogged injector in #2. Since this day of diagnostic testing, I have ran "TECHRON" through it (in gas), have let it idle and also taken it on several test rides, started out only short ones, but have gone on one that was ~ 15 miles. Here is what I've found:

Initially was still throwing same codes almost immediately upon driving, sometimes even just idling. seems to be running better and better, especially after it warms up. If I get it up to speed 55mph and clear the codes, I can drive seemingly forever without throwing a code it i keep it on cruise at approx mid 2xxx rpms. However, if stop and then accelerate from stopped, it will typically throw same codes.

Questions:

- Is this improvement a good enough reason to just wait, keep driving, and hope/assume that the Techron may eventually solve problems?

- Could the ECM be the problem, such that it is causing #2 misfire, but doesn't have its own code to identify ECM as problem? (i've read other threads of similar problems which ended up being ECM). If so, any diagnostic tests I can do?

- If I wanted to buy used ECM, would I just need one from an AHA that had a 5 speed, OR, do I also need to make sure it also came out of a Quattro too?

Any suggestions would be appreciated. thanks.

 

Since it's just throwing the code at low RPM's when the throttle is open, I still wonder if there's a vacuum leak somewhere. What kind of shape are all the vacuum hoses in above the throttle body?

 

OK, thanks I'll get on that. I need to order up some Vac line first.

For my ref later (or anyone else that may need it), some reference info for redoing the lines:

B5 30v Vacuum Lines DIY with pictures.

 

Are there 2 ignition coil modules sitting on top of the air filter box? If so...swap those 2 and check your misfire to see if it moved.

 

I'm not there to look now, but pretty sure the icm is part of the coil (built in) on this model.

 

It's a V6. Coils are on a bracket right over the PS pump up top on the front.

 

UPDATE:

At time of last posting I had thought I had it narrowed down to a vac leak. Since that time, here is what I've done (note: nothing repaired related to vac system):

- Used Techron
- drove/used up gas and put in new 93 oct fuel with more techron

ran better but was still getting same codes when put under load.
drove it on a regular basis. would run crappy at startup, then got a lot better once warm (but still threw codes)
NOTE: we'd had sub zero temps pretty much consistently for weeks around here.

Yesterday, temps reached approx 30 degrees.

Went out for drive and car ran "like new". No error codes. Scanned many times while driving, put it under load a lot, etc. NO CODES.

SO, now i'm wondering what was my last issue, was it temp related (bad coolant temp sensor CTS ). Or was it a fuel / injector issue that was solved over time ( by using techron , high oct fuel etc ).

Any theories or suggestions ?