3b timing problem

[newsh]

[WidowmakerS2]

Solved. Changed both the G4 and the G28 with known good ones. No more problems. At least I've gotten some training in setting the timing on these engines :-)

[Bowie69]

I had these symptoms intermittently in hot weather for years, replaced them both this year and not had a problem since!

[UrS4boy]

J17 Fuel Pump Relay and why it is important to an UrS

Still zero. Checked that the G40 gives 5volt and 0 when it passes the window. Fuel relay is not energized on start attempt.

Well that is almost good news. Without a G28 signal telling the ECU that there more than 13 RPM (according to Paul N.) or 23 RPM (according to Audi literature), the ECU will not energize the J17 fuel pump relay - which in turn powers a bunch of other stuff needed to start and run the car. (All pointing to a failed or dirty G28 - check my G4 and G28 maintenance post link I provided earlier today).

For more J17 and G28 info, click on this:

http://forums.quattroworld.com/s4s6/msgs/22583.phtml

[WidowmakerS2]

Still zero. Checked that the G40 gives 5volt and 0 when it passes the window.
Fuel relay is not energized on start attempt.

[UrS4boy]

Thanks! I'm working on the car right now.
I measured again now. G28 has 958ohm between 1 and 2. G4 has nothing.

Retest the G4 and if it is still zero, then you will need a new one or a good used one. You could use a G28 sender if you painted the "new" G28 end the proper G4 colour to prevent mix-ups later.

[WidowmakerS2]

Thanks! I'm working on the car right now.
I measured again now.
G28 has 958ohm between 1 and 2.
G4 has nothing.

[UrS4boy]

Crank Position (G4) and Engine Speed Sensor (G28) Info - Function , Location and PNs

Pulled out both G4 and G28 today. The G28 had no resistance across any of the pins.

Testing a G4 is something like this: "Test the resistance between between pins 1 and 2 of the black connector end of the G4. (With the bump on the middle of connector up, the pins are, left to right, 1 ,2 and 3.) Between 1 and 2 you should have "approximately 1000 ohms".
If NO = replace, If YES - test between pins 1 and 3 and then 2 and 3. Both should be infinite ohms, i.e. "open", If NO = replace. If the G4 is fubar'd the engine will not start. If the engine is running when the G4 fails, it will keep running, but never start again (until you replace the G4).

Testing the G28 sender: Set DMM to resistance (2K ohms). Connect the leads to pins 1 and 2 (1 is on the left with the connector bump on top, 3 is on the right). Must be approximately 1000 ohms. If no, replace RPM sender. If Yes, connect the DMM between pins 1 and 3 and then 2 and 3, both must be infinite ohms (no continuity).

Some G4 and G28 reading for you:

Maintenance:

http://forums.quattroworld.com/s4s6/msgs/281029.phtml

General info including testing:

http://forums.quattroworld.com/s4s6/msgs/20986.phtml

[WidowmakerS2]

Pulled out both G4 and G28 today. The G28 had no resistance across any of the pins.

[WidowmakerS2]

Is that hall sensor? They can break down when hot too!

2112 is: Ignition timing (G4)
-No signal


I've just replaced my hall sensor. It still gives the 2113 though..

2113: Hall Sender (G40)
-Open circuit/short
cicuit to positive
-Signal to positive
-Short circuit to earth
-Signal to earth
-Mechanical fault
-Fault in basic setting

The 2113 can come as a direct result of the 2112, pin for G4 missing or out of spec.

The pin cannot be missing completely, or the engine wouldn't start when cold..

[newsh]

Code 2112

Is that hall sensor? They can break down when hot too!

[newsh]

Haven't tried that yet. What would be the reason why the old one won't work when warm?

It's a classic coil fault, works fine when cold but breaks down when hot, normally causes a hot misfire though. Have you had it running in the dark and looked for stray sparks?

[WidowmakerS2]

Blink codes:

2113- G40 Will have to check wiring again? From memory, you can get this fault when G4 pin is bent or out of situ.

2223- F96 not connected

2341- Damned air leaks

2112- G4. This one is interesting..

2111- G28, engine not running.

[WidowmakerS2]

Haven't tried that yet. What would be the reason why the old one won't work when warm?

[newsh]

Try a different coil?