[CIS-E]: What does the potentiometer do, and others? a bit long...

[abatzis2 at hotmail.com (Michael Abatzis)]

still trying to figure out why the hell my car is slow (7 mos now).
after replacing an apparently not clogged cat/dp with a header, my car
is still slow. AFAIK, the ONLY thing i haven't futzed around with much
is the fuel distro. i did the electric tests, and the only abnormality
was that the air plate potentiometer was out of whack.  what exactly
does this do? i was under the impression that it was only for cold start
enrichment, but was wondering if anyone knew for sure. i guess it could
affect throttle response some also, but i does it affect WOT? 

since the car is slow at WOT, i figure i should try to troubleshoot
that, which i'm hoping is simpler than under part-throttle conditions.
here's my understanding, and anyone with a real solid knowledge of this
stuff please correct me:

IGNITION: At WOT, the ignition is pretty much static, setting timing at
a fixed value (base + 20' or something). this i tested, and it checked
out. not sure how vacuum alters it, nor the knock sensor. if the KS is
retarding ignition, would i be able to tell by testing the WOT timing?
in other words, would the value be less than the 20+'? is there another
way to see if the KS is kicking in? did the LED test light, no faults in
memory...

FUEL: I think this is purely mechanical at WOT, and the cpu basically
doesn't contribute. your DPR gets a fixed 16mA, so if i'm having a fuel
problem at WOT, it should be within the fuel distro/air plate assembly,
or fuel pumps (which are good) or injectors (which i think are good).
all the sensors and crap shouldn't really affect it, right?

I'm going to try to get dynoed for the first time tomorrow, so that
should tell me if i have a fuel prob or not, right? I'm expecting about
120hp at the wheels (2l 16v, header, tt cat back, euro intake cam). I
guess I'll update then. Opinions on this are welcome--at this point I'd
gladly pay someone to fix this, but I can't find a mechanic that I'm
convinced knows more than me (saying more about the mechanics than
me...)



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Michael Abatzis
New Orleans!
'87 Scirocco 16v, sick right now... 
'88 Scircocc 16v, RIP
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