Diagnose This: Episode 2 - a tribute to Cathy (very long)

[sukchew at cox.net (Chuck Blue)]

    I've been greasy and pissed since Sept when I decided to make a few 
improvements???????????
But I'm smilimg now.The gathering of the clan approachs.
 Everything is loaded except me.
ole blue
----- Original Message ----- 
From: "Eric S" <scirocco@vintagewatercooleds.com>
To: <scirocco-l@scirocco.org>
Sent: Monday, May 29, 2006 12:09 PM
Subject: Diagnose This: Episode 2 - a tribute to Cathy (very long)


>
> Ok, here is a reminder, see under the quote for changes/current state, and
> a "Boykoish" story of CIS woes.
>
> Eric S said:
>>
>> On this episode of Diagnose This we bring to you one sluggish VW Fox.
>>
>> Patient details:
>>
>> 1990 VW Fox Wagon
>> 1.6 liter, Heron Head 8v, 9.5:1 compression
>> Stock CIS-E
>> Stock Exhaust
>> Iginition timing at 8 degrees
>> Cam timing advanced 1 tooth, this rasied our compression to 160 psi a 
>> cyl!
>>
>> Symptoms:
>>
>> 1. Slow to rev even just idling and bliping the throttle
>> 2. Super slow, can barley maintain 80 mph, making maybe 60-70 hp on the
>> butt dyno
>> 3. Runs excellent, idle smooth, a soft miss when under load, more of a
>> surging really
>> 4. Plugs show proper mixture, O2 system not having to do any adjustments,
>> and confirmed its operating correctly (ground the O2 wire, it idles up,
>> then loads up and starts to falter, give it 12vs it dies, no change in
>> idle speed with O2 unhooked or hooked)
>> 5. Car just feels like it can't breath, similar to how the previous 1.8
>> acted, but now much more pronounced with the 1.6
>>
>> Possible causes (feel free to add on here and "vote" for your diagnosis):
>>
>> 1. Cam timing? I am already 1 tooth advanced, this got me to the proper
>> comression
>>
>> 2. Cat clogged? This could explain why I hated the 1.8 so much, and the
>> sluggishness to rev
>>
>> 3. Intake/Injection issues?  Fox intake is one of the best flowing from
>> what I have heard?  Its all the stock Fox CIS-E stuff, just with the
>> shrouds knocked off the injectors.   Cannot check DPR current (don't have
>> the harness).
>
>
> OK, so, here is what has been done/discovered:
>
> Thanks to Timbo, he reminded me of the retarded restrictor just before the
> cat that VWoA installed.  That has been removed and the cat um...de-catted
> we shall say (mmmm, platinum dust, cough cough).  This brought some
> improvement in driveability/power.
>
> Next, my mechanic told be of a restrictive screen in the main fuel inlet
> banjo bolt on the Fox CIS-E distributor.  Damn right its rescritive,
> removed that banjo bolt and replaced it with a normal one without screen
> from CIS-E-Motronic.  This made the car more rev happy and peppy for sure.
> So...still think something is wrong with fuel.
>
> Cue Cathy drama:
>
> I decide to do the spray pattern test as well as volume test on the
> injectors.  Spray pattern is crap on #3, and it flows a full %25 percent
> less at full spray than the other 3...the other 3 injectors have not the
> greatest spray patterns, but ok anyway.
>
> So I swap #3 and #4 injector (sound familiar yet Cathy?) and guess what,
> crappy spray pattern follows the injector, but the low flow sticks with
> the #3 spot, lovely.  So, clogged line or bad fuel dist are my only
> choices.
>
> Hmmm, I have no spare Fox CIS-E fuel dists now do I?  Nope, a friend had a
> set of injectors that we managed to find a good one, so solved the spray
> pattern issue....but what to do with the low flow on #3?
>
> Oh, ok, its time to get experimental!  So, I have this spare
> CIS-E-Motronic dist from my old 2.0 16v Caddy....hmmm, part numbers are
> different, but what the hell, lets give it a shot.  Bolt the spare dist on
> to the fox air flow plate....wierd, injectors spray even with plate all
> the way down, BUT the injectors all flow within 1% of each other now (and
> quite a bit more volume too!!!).   So, we adjust the Fox air flow plate
> all the way down, injectors STILL spray when plate at bottom...thats no
> good.  Time to inspect the fuel dists and air flow plate differences.
> Sure enough, the piston on the CIS-E-M dist has a good 1/2 inch more
> movement in it than the Fox CIS-E one...and you can visually see the
> differences in the pivot points of the air flow plates between the two.
> Ok, so I rip the whole fuel dist and air flow plate out and put the
> CIS-E-M dist back on its plate and re-install.
>
> Moment of truth, test the injectors and flow one last time, all looks
> good.  Pop the injectors in, and fire her up.  WOOT!  Fires instantly,
> smells way rich, lol.  Lean it out a bit, idles beautiful, smooth, no more
> missing.  But it wont rev at ALL, just bogs if you give it ANY gas.  Shit
> I think, this won't work, I'm gonna have to put the fubared Fox dist back
> in.  Oh wait, KNUCKLEHEAD!  Helps if you remember to plug the DPR back
> in...LOLOL.
>
> Plug it in, and REV BABY!  Oh, you can hear the difference just revving it
> at idle...no more boggishness and slow to rev, it SNAPS to life with just
> a little twist of the throttle!  NICE!  Still wierds me out to have some
> frankenstein fuel dist setup, but the Fox ECU seems to be happy with it
> when in closed loop, open loop is just way too rich (maybe I'll just
> unhook the cold start injector).
>
> So, its over fueling in open loop mode (cold start), but runs AWESOME
> onced warmed and into closed loop mode.  I still have more power to find,
> I can tell its still not quite breathing right, and maybe could use a
> little more ignition advance, but I can actually do 90 mph + now, and have
> a little bottom end torque I never had.  I think she can make it to Cincy
> now...she really still isn't fast yet, but am hoping a free flowing
> intake, exhaust and maybe a little ignition timing fixes that.
>
> So thats my story for the weekend...lemme know if you have any other ideas
> of where I can find my missing power, or comments about my hackage ;).  In
> the mean time, its time to do the little crap (stereo, new sport Quantum
> seats, fix exhast leak at cat, etc, etc, etc, etc)
>
> Cincy approacheth, are you greasy and pissed at your car yet? ;)
>
> -- 
> Eric
> www.vintagewatercooleds.com
>
> 1979 Dasher Coupe 2.0 8v
> 1981 Scirocco S (TDI swap project)
> 1990 Corrado TDI
> 1990 Fox Wagon 1.6 Heron Head 8v
> 1991 Cabriolet (2.0 crossflow 8v project)
>
>
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