Sortin' out your 4kq

[Ben Swann]

On Monday, November 25, 2002 3:02 AM, Tigran Varosyan
[SMTP:tigran at tigran.com] wrote:
> Hi Ben. Thanks for all of the advice, sounds like you know a lot about
these
> cars... Lets go one step at a time...
>
> From your description, it sounds like someone has done a tune on the
vacuum
> layout, or it is simply deteriorated from age and neglect, and you may
have
> some fun putting it all back again.
>
> >> Yes, I would not doubt if there has been some tweaking done before I
got
> involved... However till last Wednesday this car was called "The
unstoppable
> Audi". Partly because the brakes used to not work, but also because the
> drivetrain was bulletproof. What I am saying is that the car ran fine
till
> suddenly at a light *PUFF* *PUFF* *DEAD*.
>
>
> Once you get things sorted, this car
> will run quite nicely, and will be easy to keep it that way.
>
> >> Man I hope so. Im in a real bad spot right now. Money was short to
start
> with. Timing belt skipped on my Mitsu (new engine time) and now this... I
> was already looking at $400 beaters online... I cannot belive this car
let
> me down...

Stay the course with this car and it won't let you down.  The '84-87 4kqs
are probably some of the most reliable cars, especially for their day.  It
may not be the fastest, but will get you through things that many newer
cars won't.  My wife won't drive anything else, as her 4kq has seen her
through blizzards, and she is really a chickenhead when it comes to
driving.
>
> 1) Check for vaccum diagram on the hood, and reconstruct all vacuum
> routing.
>
> >> I have a manual for the car and I have the sticker under the hood.
Nether
> show where all of the lines go. I can hook up what is on the sticker
since
> it does not seem to be causing the problem, but I will still have a ton a
> vac lines left over. Including some stuff that goes into my passenger
side
> fender!!]

Well hook up what you can, and by process of elimination, you can find the
rest.  Most of what goes under the fender is either carbon canister for
fuel recovery, or vacuum reservior - not critical, but good to have.
> > There are not many lines I can think of that don't serve some key
 purpose, so ports should not be blocked off.

OK - despite what I said earlier, block off anything you are not sure of
for now.  Replace all old lines with new.
>
> >>Im sure that until I can get it working the car can live without the
PCV
> :) The intake side is blocked, for now the crank case is venting to
atmosphere.
>
No, fix this, as it is a massive vacuum leak.  I'm sure you can find some
suitable hose at the local FLAPS - you don't need to but the expensive hose
from the dealer.

> It is not that complicated  once you dealve into it.  A clean motor helps
sort out what may at first  appear to be spaghetti.
>
> >>Agreed. I just wish to know where all of these lines are supposed to go
to.

There aren't that many.  1/2" hose from side of waffle boot to Idle Stab
lization valve (ISV); 1/2" hose from bottom of waffle boot to Crankcase
housing (PVC); 1/4" on top of waffle to charcoal cutoff canister; another
taps into cahr. cutoff valve with other end to char canister;  throttle
body hose goes to other end of char cutoff valve(control port); cruise
control hoses, brake booster hose go to intake manifold;  Pressure
regulator diaphram hose - refer to diagram on hood.
>
> 2)  Get yourself a proper Bentley service manual,  at least a Haynes.
>
> >> I have a Haynes and it will be burned in a big camp fire soon as I get
 this figured out. There is NOTHING on CIS-E in there, period! I hear the
 Bentley is good but nobody around here has it...

The Haynes is better than nothing.  The Bentley will pay for itself the
first time you use it.
>
> 3)  Don't take the fuel distributor apart, not yet anyway.  The fuel
 pressure is far more than adequate, and may even be too high, but not
 likely a problem.
>
> >>Too late. Already torn apart, sprayed out with B12 and put back
together.
> I also think that high pressure may be the problem. I read online that
this
> can bind the distributor plunger and cause to get stuck.
taking the fuel distributor apart was a bad move, but like you said too
late.  Hopefully the car is running like it was before and you didn't make
it worse, in which case you are lucky.

Unblock the differential pressure regulator - that is undoubtedly the high
pressure problem, since that controls fuel return, and right now you
probably have no little or no fuel to injectors no return to the tank.  If
you have a dealer nearby, see if they have the differential pressure
regulator o-rings, usually sold as a kit - mainly two small viton(green)
o-rings.  I've been generally successful cleaning what is there however if
none on hand.
>
> 4) Air-flow sensor plate under the giant waffle hose thoroughly and
install  new air filter.  Make sure plate lifts freely and does not bind -
it needs  to be centered, and you will probably find grit and crud in there
which  causes a great "ah hah!".   Also, clean the throttle body while
waffle hose is off..  Reattach all vac. hoses, and larger hoses.
>
> >> plate moves freely and looks centered. It was full of grime but that
got  cleaned off Thursday.
OK _ that will help when the actual culprit is ruled out - most likely diff
pressure re. and/or thermo sender.
>
> 5)  Clean the CIS-E fuel differential pressure regulator which is mounted
by two screws on front of the fuel ditributor.  Remove the screws, and
clean surface with carb cleaner, o-rings are probably pretty grimy -
replace if needed with $7 kit from dealer.
>
> >> surpizingly it was pretty clean in there. O-rings seemed to be ok.
> Sprayed B12 in there anyway.
>
> If real bad, you may need to disassemble regulator and clean inside, but
start by removing and cleaning mating surface outside just to see if it
helps running.
>
> >>How do you disassemble it?!
Hold on that - check/replace the thermo sender.    Get a new one from
Rod at theparsconnection.com - check their website, call Rod and order.
>
> 6) I have found the Themo-sender which is screwed in the bottom of the
 coolant neck to cause the type of problem you are describing.  That would
 be after everything else is tight however, and it sounds like you are a
 long way off from trying this as prime suspect.

Sounds like you are closer as this now sounds like the culprit.
>
> >> If anything, shouldnt that make me run rich? I think I am running
lean...
> Plugs are nice and dry when engine dies...
They go out of spec. in either direction.  I think you should see 2.5k ohm
at 68 deg.F

>
> 7) Pull fuel injectors and check spray pattern and replace o-rings.  This
BTW is a good item to start with to make sure you are actually getting fuel
properly sprayed into the engine.
>
> >>Now that I think I know how the injectors come out, I will give that a
shot first thing in the morning. I wanted to do it before but could not
break them lose.
>
> To do this, jump the fuel pump relay socket large terminals to operate
fuel pump and lift sensor plate -
> injectors should  spray nice conical pattern.   Replace injectors if
really bad, but usually an imperfect pattern will not kill the motor.
>
> >>Well, I have been starting the pump via the terminal in the fuse box,
however for interest's sake where is the relay? I tried to look that up in
my great Hayes manual, but again, could not find it.

You've been doing that right.
>
> 8) last but perhaps could be first - you might consider a good degreasing
to make things a little neater to work on.  I usually do this after I have
the engine working fairly well however, so use your judgement.
>
> >>The plan for the car sometime next year was to get it SCCA ProRally
legal for the Oregon Trail race at which point leaky gaskets making a mess
of my engine bay were to be replaced. At this point it would be a waste of
time as the damn thing just spits it back out :)
>
Check those injectors, but order the thermo-sender first, so you have on
hand.  It is over $100 at the dealer, but only around $25 at
thepartsconnection.
> See comments below to your original enqury.
>
> What else??? Huw?
>
> Ben
>
> >>Again thanks a ton for the help. I have a few things to do tomorrow
morning...
> Car:
> '85 Audi 4000CS Quattro.
> 5 Cyl 2.2L
> Fuel Injected.
>
> Problem: Car starts up, runs for about 10-30 sec in idle or 2-5 sec under
> load and dies. When not moving I can rev the car, the engine sounds fine
> everything is great and then suddenly it sputters and dies. When I try to
> move it, it will run for a very short time. The car needs to sit for 2-4
> minutes before running again. If left to sit longer the engine seems to
> work a bit longer too.

THERMO SENSOR!