Urs4 dying

[Kieron20V]

Hi chaps, I'm going out of my head trying to sort this one out, so any ideas?

My rs2d s4 was running perfectly when I parked it up in the garage about 3 months ago. I was unsure what I was going to do with it as I am buying a house. I decided to sell it for extra cash so about a month or so ago I re insured it and took it for a drive. It ran like crap, barely idled and missing almost constantly.

So I checked all the obvious, nothing amiss. Got a coil tester and found 1 coil weaker than the others. Ideal time for a 2.0t conversion.

Fitted that, new coils, new harness, new 7ek plugs and it's still just as bad, but it actually does now when it's been revved just stood still.
When it's revved quickly over about 4k, enough to start the turbo spooling really, it dies. I've checked, and it's actually cutting the fuel pump relay.

There are no fault codes whatsoever which is really puzzling me.

It still cuts out with the same behaviour with the mad unplugged too, so it's not like it's sensing a boost leak.

So, any guesses? The car pulled perfectly before being parked up, running a good 26-28 psi on a prj stage 3 map.

Yours faithfully, disgruntled owner.

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[mike74]

have you tried jiggling/wiggling resetting the MAF plug at all?

[Kieron20V]

Yes it's fine, I've cleaned the contacts also. But it's the same behaviour if it's plugged in or not.

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[Error404]

What do you mean when you say cutting the fuel pump relay mate?
As that is energised by the ECU AFAIK, perhaps you have a wiring issue or some corrosion in the fuse box / ECU connector or an earth problem?
Have you tested the fuel pump by manually triggering the relay?

[Kieron20V]

I heard clicking when it cuts out, pulled the cover off the relay and when it dies, it dies because the relay is cycling on and off. It's only once it's revved it does that.

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[Error404]

Is the ECU losing 12v supply also?

[UrS4boy]

Potential solutions to why your AAN-powered UrS isn't starting

I heard clicking when it cuts out, pulled the cover off the relay and when it dies, it dies because the relay is cycling on and off. It's only once it's revved it does that.

I don't believe that there are any issues that would cause the ECU to shut the fuel pump off (via the J17 relay) at 4000 RPM. You have a basic fundamental issue of some sort. I would start with replacing the Fuel Pump Relay. Also you might want to put spade fuses in ALL of the four fuse locations above the ECU to eliminate issues with the thermal breakers.

Did you see my monthly reminder post yesterday? Item 4:

Potential solutions to why your AAN-powered UrS isn't starting:

http://forums.quattroworld.com/s4s6/msgs/210191.phtml

Callout for the Above ECU Fuse Panel Fuses - UrS4 and UrS6 differences:

http://forums.quattroworld.com/s4s6/msgs/137287.phtml

[imp998]

Does it drive? If you could limp it round to mine, You can try my MAF. I have a spare ECU too

[RichLV]

I had a very very similar problem. It did not die, but it was misfiring horribly, across all cylinders. And during those violent misfires, FP relay was ticking on and off, which put me off the real problem. Was the damn, new F5DP0R plugs which I swapped a month before. Changed the plugs - issue went away. I went over the whole car while battling with it during 3 week period - MAF, WG, boost leaks, wiring, ECU swaps, etc.

It dies even when you rev it while standing still? Or only under load?

[Kieron20V]

Dies just revving it. Not bothered trying to drive it yet.

Will check tomorrow if ecu is losing power too when it dies.

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