Problem solved? (Tyson's stubborn 4ksq)

Tigran Varosyan tigran at
Mon Dec 2 23:01:31 EST 2002

If this is it, the cookie goes to GMBCHEF and Paul Cole for helping me with
info that eventually got me to track this bugger down. If it does resolve
the problem, I will post a full write-up for the archives. THANKS A TON to
EVERYONE whom has helped me with this!

#1 Auto wreckers around here SUCK! Their pricing works not like most junk
yards (almost by the pound) but rather pulling up the part number, seeing
what a new one costs and trying to gauge you for as much as they can. I paid
$108 for a Diaphragm Pressure Regulator, which as far as I know is just a
sping-loaded vlave. This is the part I had asked about 4 times, I just
didn't know what Audi called it. Most cars I worked with they are just "Fuel
Pressure Regulators" or something.

Ether way, following the steps in the Bentley I found that pressure in the
distributor was at over 110 PSI whereas it should be no higher than 80ish.
Manual said to check the return line, which I did and then said to replace
this regulator, which is a simple mechanical FPR. Turns out Audi wants $350
for it...

Long story short I got my hands on one, put it in, and performed the
"injectors in a bottle" test. Good Lord! Do they ever flow now! The sensor
plate was still pretty dang stiff but not as bad as before. Moving it up and
down made the injectors work exactly as they should and spitting out a
GIGANTIC amount of fuel when the plate was all the way up. Spray pattern was
a nice cone at idle which turned into a gushing stream at at WOT

Decided to start the car, it turned on, I can rev it, it does not die!!!!!
But now I got the exact opposite problem than before. Instead of not enough
fuel I got WAY too much! Its running so rich that I am amazed its running at
all. BUT IT RUNS!! Tomorrow once I get the fuel pump, filter and all the
goodies tucked back up I will try to drive and see what happens.

Having as I have taken the fuel distributor apart a few times, I must have
the fuel ratios out of whack. I recently found out that the big brass nut at
the bottom of the plunger is not just for fun :) I will reset that to proper
position and see where that gets me. Also the 3mm Allen wrench, I will give
that a shot too. Hopefuly I can lean it out. It is possible that this thing
has been failing before and previous owners just made the mixture richer and
richer to compensate.

If all else fails, I am glad to know I have you guys for support here.

Again, thanks to everyone for your help.


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