Home Technical Discussions Audi 4000, Coupe/GT: 1980-1987 (B2)

Audi 4000, Coupe/GT: 1980-1987 (B2) what the....???


Permlink Replies: 7 - Pages: 1 Threads: [ Previous | Next ]
Last Post: Apr 4, 2008 10:19 PM Last Post By: FKH161
cowinthefog

Posts: 36
Registered: 06/23/07
what the....???
Posted: Mar 19, 2008 5:51 PM
  Click to reply to this thread Reply
I have a 1984 Coupe GT, With California smog junk. I checked the vin, so I know that's correct. I have several sensors I can't identify...so I am hoping by posting a few pictures, someone can throw me a rope and help me figure them out. I appreciate any answers you can give me. I have discovered that it seems there are several years worth of sensors and things here, since I tried changing the fuel injector o rings and discovered that the fuel injector holders are from an 82 coupe, though the injectors are from an 84. The sensor with two vacuum lines on it seems to be from an 83 or 85 system with carburetion, the catalytic converter on is from an 82-83, the wiring is from an 85, why are there TWO vacuum lines on my warm up regulator? All the ones I can find on any model across several years have one or none...I am sooooo confused now...Thanks, Josh

1. Big gold one coming out of the back end of the head-

2. Has a green and a black vacuum line coming from/going to it-

3. Three do-dads on fuel metering body- Left to right please-

4. Big round one down on left side of block, with two screw on connectors-

5. Single connector just below number 4-

6. Two pin connector on top side of upper coolant connector housing-
FKH161

Posts: 7,661
Registered: 12/29/05
Re: what the....???
Posted: Mar 20, 2008 12:57 AM   in response to: cowinthefog in response to: cowinthefog
  Click to reply to this thread Reply
Not 100% sure on these... someone please correct me if I'm
wrong (I don't see a lot of Audi's, just going by what looks
similar to VW's).

1 - cold start thermo switch?
2 - vacuum thermo switch do you have an EGR?
3 - a) round metal - fuel pressure dampner or check valve
3 - b) frequency valve (should buzz all the time when the engine is running)
3 - c) boost solenoid (should click when idle gets low... wich raises idle)
4 - oil pressure sensor, 1 wire for oil light, 2nd for gauge
5 - also oil pressure switch
6 - thermo switch (for frequency valve)

edit - try to keep images smaller for easier viewing (not everyone
has a 24" monitor) ;-) You can always upload larger when
people request it/them

Message was edited by: FKH161

FKH161

Posts: 7,661
Registered: 12/29/05
Re: what the....???
Posted: Mar 27, 2008 10:19 PM   in response to: FKH161 in response to: FKH161
  Click to reply to this thread Reply
...any updates?
cowinthefog

Posts: 36
Registered: 06/23/07
Re: what the....???
Posted: Apr 3, 2008 5:52 PM   in response to: FKH161 in response to: FKH161
  Click to reply to this thread Reply
I have only solved some of the mysteries surrounding this little car. If I unplug any one of the wires you mentioned for the oil pressure gauges, which you thought there were two of, I still have oil pressure on my gauge.....?? Man, this car is soooooooooo weird. I was told it's got the CIS-E setup, but since I have gotten my Bentley manual for it, I have discovered it is not the CIS-E, but the standard CIS version. It does have an OXS system, and it is a California car, which may account for some of the intense weirdness. What looks like a fuel pressure regulator next to the fuel metering body is totally unidentifiable to me. I find two numbers on it-280161202 and 049133533. It does not look like ANY of the regulators I can find for ANY Audi model from 1980 through 87, unless there is some obscure application. The one in the back of the head appears to be the thermo time switch, the one near the distributor is a thermovacuum switch-from a 1982 model. I can't find a single Warm-up regulator with TWO vacuum lines running to it. I also have no idea how this is supposed to work, since I took it apart to clean in and noticed none of the three sections are connected, except for the springs interacting with the electrical connector. How in the world is the fuel pressure altered? the passage appears to simply be fixed and open from the line in to the line out. I have read it, but it makes NO sense to me. Nothing can alter the fuel flow through this thing.
The car doesn't idle smoothly when cold and is only marginally smoother when hot. However, once driving it seems to be fine. No hesitation or anything. I have yet to sort everything out, it still gets a bit hot, which I attribute to a sticking thermostat and a somewhat plugged system. This is easy. It shifts very smoothly, not bad considering it sat for about three years outside. I fear it has parts on it from years previous to my manual. I don't want to have to buy two manuals for this thing. Any idea why I might have such a strange spread of years wirth of parts on this thing? It doesn't APPEAR as though the previous owner could have switched ALL this stuff that's weird or different...At least it drives nicely and the heater works! Thanks, Josh
FKH161

Posts: 7,661
Registered: 12/29/05
Re: what the....???
Posted: Apr 3, 2008 9:59 PM   in response to: cowinthefog in response to: cowinthefog
  Click to reply to this thread Reply
CIS, CIS-Lambda, CIS-E, CIS-Motronic

Since you have an O2, I'd say you have CIS-Lambda... which
explains the "frequency valve" that is visible in one of your
pictures.

The thermo time switch, if not providing continuity when
cold, will cause the engine to run rough when cold. Once the
engine actually gets warm, it will run better since the ECM
is now actually able to monitor fuel mixture with a fully
warmed-up O2 (and the fact that the leaner fuel mixture is
now able to burn better in a warm engine, compared to when
the engine is cold).

Bridge the 2 wire sensor with a bare metal paper clip
before you start the engine on you next "cold" start and
see if it runs better cold.

If it is CIS-Lambda, you will have to adjust/check the
duty cyle... but if it runs good warm, it must already be
close/in the ball park.

I've cleaned several warm-up regulators in my day... it's
kind of hard to imagine how it works when those small
passages are pressed together when assembled.

You'll need a CIS fuel pressure gauge & adaptors to be able
to see the cold-to-warm transition of pressure. This is
an important step to do, since without knowing what the
pressure is doing... you could end-up chasing your tail
for quite a while (when trying to sort-out running issues, be
it cold or warm).

Warm-up regulators with vacuum lines... I'll have to look
into that one. IIRC, the 5000 Turbos had one with 1 line
but I also don't recall ever seeing one with 2.

As for the oil pressure gauge, does the gauge actually
move according to engine rpm (pressure increases as revs
go up) or does the pressure just max out at 5 bar?

If it max's out, you probbaly have a short in the
gauge/circuit.

Message was edited by: FKH161

cowinthefog

Posts: 36
Registered: 06/23/07
Re: what the....???
Posted: Apr 4, 2008 6:44 AM   in response to: FKH161 in response to: FKH161
  Click to reply to this thread Reply
CIS-LAMBDA sounds good. :) I think the circuit that runs the frequency valve is OK, (though I haven't checked it yet) because I can hear it buzzing when the car is running.

I'll try the bridge trick with the thermo time switch.

My oil pressure fluctuates with engine RPM. I believe it functions properly. I have never had an oil temp gauge, though.

I have a simple fuel injection pressure tester....will it work? Or are there tricky things I need to go with it? Like a way to shut off the pressure?

The screw on the passenger side of the intake manifold near the back...the idle speed screw. If I turn it and nothing hapens, what does that mean? Can I take it out and clean the orifice? New O-ring?

Any idea on the thing pretending to be a pressure regulator?

Thanks, Josh
cowinthefog

Posts: 36
Registered: 06/23/07
Re: what the....???
Posted: Apr 4, 2008 5:51 PM   in response to: cowinthefog in response to: cowinthefog
  Click to reply to this thread Reply
I took the throttle body off today and cleaned it out really good. Now I can actually adjust the idle via the idle adjust screw.....imagine that. Lots of coking in there...gooey fuel residue. I imagine that will help the cold issues...but I haven't checked since it was still hot from driving. I have yet to try the bridging of the thermo time switch. Once it's cold I will.

My tests of the warm up regulator seem within specifications. I just wich I understood how it worked.

where is the serial number/model number located on my trans? It's an automatic. Thanks, Josh
FKH161

Posts: 7,661
Registered: 12/29/05
Re: what the....???
Posted: Apr 4, 2008 10:19 PM   in response to: cowinthefog in response to: cowinthefog
  Click to reply to this thread Reply
Some info about the warm-up regulator (with diagram) here:
http://www.auto-solve.com/mech_inj.htm#MFI10

Sorry, can't help you with tranny numbers...

Point your RSS reader here for a feed of the latest messages in all forums

Popular Discussions:
No popular dicussions.
Popular Tags