From Audi 100 to urS4 in a week

[S2central.net]

If you are certain that the fuel pump relay is not being activated by the ECU then either a fuse is blown or the signal from G4 or G28 isn't good... The ECU needs to see something like 13rpm by analysing the crank signals before it activates the fuel pump.

Tis true the fuel pump relay is being activated but as stated above - check you have decent connections into the fuel pump - a bad earth there will essentially stop your pump.

These things almost always boil down to something really simple.

[hunker7]

My inital thought was that I ran out of petrol, then when it didn't start after putting fuel in, i thought it's fuel pump, because it juddered twice and then loss of power.

I could check what is g28 seeing through vagcom, if it's way out then we have our answer.

But wouldn't it show an error if it doesn't get usable signal?

[Error404]

G28 is hard if not impossible to diagnose in VAGcom as it will show as a fault without the engine running, but the engine won't start without it.
So you will see a G28 fault (which is normal without engine running) or you have a non-start!
If you can activate the fuel pump manually with the cover off the relay, and you have a good G40 (I think you already replaced that?) then you have your problem. ECU is not seeing the right signal from the G28. Dodgy sender or more likely from how you have described the breakdown, slipped timing.

[hunker7]

But if i crank the engine G28 should show up a reading shouldn't it? I replaced G28 and G4 couple of month ago.

G40 I didn't replace, but if faulty, dead, should show up as an error.

[Error404]

you can easily test the G40 with an LED:

Uncle Dave has done the hard work for you: http://forums.quattroworld.com/s4s6/msgs/22580.phtml

[hunker7]

Cheers. Will start with easy stuff

[S2central.net]

you can easily test the G40 with an LED:

Uncle Dave has done the hard work for you: http://forums.quattroworld.com/s4s6/msgs/22580.phtml

Yes but that only verifies the sensor is active - it doesn't tell you if G40 pulse is at the right time with respect to crank position.

[hunker7]

If everything would be fine, what sort of reading should G28 see when I crank the engine?

[S2central.net]

You won't "see" it properly without an oscilloscope - it's a sawtooth shape

[hunker7]

Where do I look for crank pulley bolt?

Does anyone know someone who might have the crank locking tool?

[S2central.net]

Use my guide for part numbers to order - I would use TPS.

For the crank lock tool - just ask nicely around here - am sure someone will let you borrow one.

[hunker7]

Juat checked the fuel pump, and that is running. So it's not getting the right signal.

[hunker7]

After an hour this is where I am at :





Cam is aligned


Crank is all out


S2Central, you said you would use TPS, what is that?

I am glad I bought the water pump, as that hasn't been done when timing belt was changed. Unbelievable how people would risk to destroy the engine to save £30

[Error404]

You don't mess about do you. Well done, looks like you have found your problem. Hopefully the keyway is not destroyed on the crank nose. Make sure you replace the lower belt sprocket (Terrybullwon's billet items are very nice indeed if you can stretch to £100).

[hunker7]

You don't mess about do you. Well done, looks like you have found your problem. Hopefully the keyway is not destroyed on the crank nose. Make sure you replace the lower belt sprocket (Terrybullwon's billet items are very nice indeed if you can stretch to £100).

I don't really have time to mess about, got just over a week to get this done.

By lower sprocket you mean crank pulley?