[s-cars] Stumbling saga......quick pressure test question.....

[Mike Sylvester]

The f5pdor plugs have a very small conductor compared to a typical spark
plug.
I've seen ok looking plugs be bad.

I believe that one of the reasons our coils fail is due to bad plugs and
boots.
When the plug has a high resistance and you add boost, it can't spark so
the voltage spike inside the coil will cause it to break down
internally.
That is why when you do a compression test, you're suppose to short the
coil outputs to ground.

Mike

www.urq20v.com

> -------- Original Message --------
> Subject: Re: [s-cars] Stumbling saga......quick pressure test
> question.....
> From: "Jim Fleischer" <jim at almgt.com>
> Date: Wed, December 02, 2009 3:35 pm
> To: "Mike Sylvester" <mike at urq20v.com>, <djdawson2 at aol.com>
> Cc: <s-car-list at audifans.com>
> 
> 
> Hey guys,
> 
> Very timely response, Mike.....I just pressure tested the system and was 
> losing an incredible amount of air out the oil filler cap.  When I pressed 
> on it, I only heard some air coming out of the rear of the top end....I do 
> have a little bit of oil seeping out the rear valve cover gasket, and I 
> think that is where the air was coming from.  Everything else seems buttoned 
> up.  Is there supposed to be that poor of a seal on the filler cap?  The car 
> stumbles, but keeps running when I remove it.
> 
> I also took a look at the spark plugs this morning.  They are the preferred 
> Bosch model, and the tips looked very worn, down to a needle-like tip.  Not 
> sure what they are supposed to look like (I didn't put these in) but I've 
> never seen a plug look like that before.  On Dave D's suggestion, I have 
> some NGK's coming to me tomorrow and will put those in and see if there's a 
> difference.  Hopeful.....
> 
> There was a very minimal seepage of oil in sparkplug wells 3 and 
> 5......mostly dry, with plug #3 having a little oil on the threads and 
> around the casing.  No puddling or really any wetness, mostly very little 
> dried around the well walls.  Very easy to clean up.  Can't imagine that 
> this is the cause of my stumble, but I defer to the list.
> 
> I also unplugged each injector, and the car ran worse in each instance.  I 
> could feel the miss much more immediately upon starting out, and was very 
> consistent everytime, whereas my usual stumble is intermittent, and getting 
> more severe every day it seems.  So, at least for the moment, it seems like 
> there is no problem with the coils.
> 
> On a lighter note, took the ur down to the FLAPS down the street.  Nice 
> excuse to wake her up before a long winter nap.
> 
> Feedback welcome as always.  I'm hanging it up for the day until the plugs 
> come in tomorrow AM.
> 
> Thanks for the help!
> 
> Best regards,
> 
> Jim Fleischer
> '95 s6 avant
> '83 ur
> 
> 
> ----- Original Message ----- 
> From: "Mike Sylvester" <mike at urq20v.com>
> To: <djdawson2 at aol.com>
> Cc: <jim at almgt.com>; <s-car-list at audifans.com>
> Sent: Wednesday, December 02, 2009 12:49 PM
> Subject: RE: [s-cars] Stumbling saga......quick pressure test question.....
> 
> 
> If you don't block the crankcase breather then you loose air out the oil
> fill cap, therefore the pressure never gets high enough to expand the
> MAF hose.
> 
> Mike
> 
> www.urq20v.com