[Vwdiesel] New nozzles, compression and stealerships... (fwd)

[Val Christian]

Sounds like #4 should be checked for injector leakage/spray pattern.
Both of those can be responsible for the tip cutting of glow plugs.

It's probably been covered before, but you want to make sure that your
glow relay isn't cycling when it shouldn't be.  Dimming lights are 
a sign.  An indicator powered from the glow relay is another.  When
what gets into the glow relay, and it will, then the relays sometimes
get in a frequent cycle mode.  In an early VW, I simply ran a relay off
a fog light switch, and manually glowed the plugs.  (That's really a 
preferred way, in my book.) 

Also, if all you plugs are frequently failing, you need to eliminate
dripping injectors and poor spray patterns.  I've only had that 
problem a couple of times, and it was when I was new to VW diesels
(like when my 78 got 100K miles around 79).  

I'm not an expert on this, so tap the "injector team".

Val




> 
> Tonight I installed my new injector nozzles in my '85 Jetta 1.6NA (thanks 
> Jan! :-)
> While they were out, I observed a few interesting things: first, the #4 glow 
> plug was gone *again* - I just replaced them one *week* ago, after 3 were 
> bad. Hmmm. Then I noticed that #4 had *two* heat shields in the injector 
> hole, and the injector was coated with fuel/sludge. Coincidence...? I doubt 
> it. Then I did a compression check with new gauge - results were 
> 390,430,450,350, with #4 showing the lowest, again a coincidence? (I 
> noted the pulses on #2 & 3 were quite "sharp" and climbed quickly, while 
> #1 and 4 were sluggish)
> The interesting part is this: I have a full service history on this car, and *all* 
> service was done at the dealer, including a new injection pump at 250k 
> kms. This is the first time I've pulled the injectors, so it appears the #4 
> extra heat shield was done by the dealer, and has been that way for at 
> least 50k kms.
> 
> Before I plan on a tear down to deal with low compression on 1 & 4, I'm 
> waiting for my valve tools to arrive so I can adjust the valves. I know they 
> were out a year ago, and I doubt they've fixed themselves ;-)  ... so I'm still 
> hopeful an adjustment of the valves might even out /boost the 
> compression numbers. Engine has 290k kms with most of it (200k) done 
> in the first 5years of its life, then very little for 12 years until I got it with 
> 250k on it. Any thoughts are welcome - this is my first time playing with a 
> diesel compression gauge. :-)
> 
> --
> Shawn Wright
> I.T. Manager
> Shawnigan Lake School
> 
> 
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