update on the power saga

Wed Jul 23 00:49:02 EDT 2003

so, no updates for a couple weeks now on the way McUrq's treatin' me...

so, recap:  intermittant power under load -- sometimes almost full
power, usually not even close... it pulls normally till 3000 rpm,
then it just loses it's will... i have JUST replaced (as in done as
part of the head project or since i have gotten it running -- past 6
weeks): head, EM, both fuel filters, wot/idle switch, isv and ecu
temp sensors, multifunction temp sensor, michelin man hose, built a
custom hosing system from intake plenum to turbo, o2 sensor, wired in
a relay at the battery for the fuel pump, new battery,
cap/rotor/plugs (new plug wires are on order, ordered a set of
magnecor wires to replace the nology ones that i think are out of
spec)... and im sure many other things that im overlooking...

so, what i've noticed is that when i start it up in the morning, and
i start driving, when i come to the first stopsign after leaving from
my house, the car acts like the fuel delivery was shut off
completely... it completely cuts out,and acts as though i just went
around a hard turn with a gallon or two of gas in the tank and is
starting to get the fuel flow going again (and this is with a freshly
filled gas tank).

from idle -- still cold -- if i try to rev the engine, it severely
misfires at about 1500-1800 rpm, and then the revs rise as usual.

once slightly warm, those symptoms go away, to be replaced by the
strange power issues that ive been detailing to y'all so far...

i have now taken a couple long-ish freeway trips with it, and it
actually seems to do better (as in slightly more consistent with
having more power) on the freeway... it will sometimes accelerate for
a little bit as it should, other times not... also, at part throttle
and about 4-6psi of boost, it will accelerate ok from about 2500-3000
rpm, and then i can feel it lose most of the power that it was
beginning to build up...

so, i dunno... i've replaced just about every sensor that i can think
of that could possibly cause this problem with absolutely ZERO change
in this behavior.

i doubt it is the spark, but i checked the plug wires, and cylinders
1-3 were out of spec for stock wires at 1700-1800 ohms each (but they
are nology wires, so i dont know what they are supposed to be), but
cylinders 4-5 were barely within stock spec at 1200-1300 ohms...  so,
i suppose it is possible that they could be the problem, but im not
sure.

i am still getting the strange 'pffft' sound in between shifts.  i
have no bypass or popoff valve.  i have checked, rechecked, and
checked again my entire intake system... all of the major hoses are
quite solid and i simply cant find anything that would cause that
kind of noise.  beyond that, it does build the correct amount of
boost, and it does it quite quickly (k24), so i dont know what to
make of it.  im trying to determine if this sound occurs more when it
is cold (it seems to) vs. when it has warmed up a bit...  so, this
would make me wonder if perhaps under strong vacuum, it is going too
lean from air leaking in, and that could be causing the problems that
are most strongly noticed at part throttle, but i dunno.  i just got
my a/f ratio meter, so i'll be installing that this weekend and doing
a couple tests...

i have gotten a couple suggestions to replace the metering head.  in
my garage i have the metering head/ injectors/pressure regulator from
an MC engine.... the one i have now is from the UrQ's original
system...  i have to figure out how to make the lines work, but im
sure i can figure that one out, we'll see...  so, that would be my
first line of defense vs getting a new one, but i dunno... the whole
symptom of fuel cutting out completely like it does when cold seems
to point to the fuel pump...

and on the note of the fuel pump, it was replaced about a year before
i had to pull the engine on the car.  it is a unit from a 20v coupe
quattro w/ the larger intake size... and i drained the gas tank
completely and filled it with about 1/4 tank of gas before i ever
started it.... but i dunno, perhaps all this time, it really is the
pump.  it is very loud (i can hear it inside of the car), but it is a
consistent buzz and it hasnt been making that strange crackling noise
since that one day that i heard it...

so i dunno, anyone have any thoughts? perhaps this is the early stage
of a fuel pump that is going out?  maybe it works extremely poorly
when cold, and then once it warms up a little, it can flow things a
bit better?

anyway, any thoughts would be great... once i get the a/f ratio meter
and the new magnecor wires on the car, that will give me a bit more
info...

thanks in advance, as always. :)
--
MswmSwmsW

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The solution is obvious.  We all have to become dumber. -Jon Rappoport

So crucify the ego, before it's far too late
To leave behind this place so negative and blind and cynical,
And you will come to find that we are all one mind
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