From Audi 100 to urS4 in a week

[Bowie69]

A cheap fix lol....

[hunker7]

By the looks of it I've ran out of petrol.

Fuel gauge still shows 1/4 of a tank, so gauge has gone wrong, and I am just hooning around thinking i have fuel in my tank.

[hunker7]

White plugs have 12v in each pin, earth is nice and tight and shiney.

I fitted new VDO pump on my A100, didn't do many miles, and then put it on S4, but now I opened inlet pipe by the fuel filter, operated the fuel pump (with switch within the relay) and there is only air coming out, and occasional splutter of fuel but no-where near what is should be.

If 2 cyls are working, then it still should at least try to start, but mine just cranks over and that's it. I have a spare pump, so might as well risk it and chuck it in.

[Error404]

If you've got no codes this has to be something simple. Earth eyelet for the coils in good condition, clean & tight?
Also check the engine harness earth points to the inlet manifold, engine earth strap & check earth posts in the cabin for the ECU & engine harness.
As John said you have +12v at the white plugs for the coil harness?
Check fuse for coils & test continuity across the fuse (sometimes they look visually OK but have a bad connection in the fuse itself).

EDIT: Yes make sure the pump is delivering correctly. I thought you fitted a new pump? Or was it a used unit?

[hunker7]

I might be a bit paranoid about fuel pumps, but it might be the fuel pump. I opened the hose by the fuel filter and manually operated the pump, and there is nothing coming out.

[newsh]

1. Unplug injectors, lay coil packs on cam cover with spark plugs in them and crank to see if all plugs are sparking.

2. Do compression test.

[hunker7]

You haven't just blown a boost hose or something?
Clutching at straws here

Or the maf came unplugged?

MAF plug is on I'll check the hoses tomorrow just in case, not like I have much left to check.

[newsh]

You haven't just blown a boost hose or something?
Clutching at straws here

Or the maf came unplugged?

[hunker7]

vagcom lite of some sort

[newsh]

Are you using Vagcom to read the codes?

[newsh]

The 2 white plugs should carry 12V to the coils, check there is 12V on all the pins on both plugs.

[hunker7]

I did an output test, and all the solenoid valves worked fine.

[hunker7]

Does it start/crank?

What happens when you try to start it?

Fault codes?

ECU communication?

Do you have vag com?

How do I check that?

No fault codes. It cranks but doesn't fire. I managed to start it in the morning, but only cyl 1 and 2 were running, 3 4 5 nothing.

[andy10v]

Does it start/crank?

What happens when you try to start it?

Fault codes?

ECU communication?

Do you have vag com?

How do I check that?

[hunker7]

Can we start again with the fault diagnosis, as in what is now happening this time?

Driving up hill, cylinders 3,4 and 5 stop working?

Driving up hill, boosts as it should but revs slowly dropping. As if you would take foot off the throttle leaving in gear.

POS changed-no difference?

Yes

Coils changed-no difference?

Yes


Does it start/crank?

Fault codes?

ECU communication?

How do I check that?

Basics-fuel? Spark?

Spark plugs are wet so fuel is being delivered, haven't checked the spark yet.

Is there anything you have removed to do the timing belt that has not been fully re tightened?

Mostly covers. didn't remove any sensors.