I need help!

Relay sockets are unreliable IME! Try some contact cleaner and judicious wiggling.

I'm off to Old Mill tomorrow, i'll have a chat with Kev.

Cheers Nige, I'll probably book it in with them to look at once this weather has passed so any light they can shed on it would be great.

Andy

Had a word, his exact words where 'bypass the existing circuit with a new one relay fed'

Could be a few things, but that's the best option matey. Thats what he would do & has done a few times.

I wonder if it's ok to run the new circuit from an ignition feed via a relay or should I use the ECU output to drive it as with the existing one? Think the only real difference is that the ECU feed primes the system with ignition, then stops until engine is running. Guess it also cuts it if engine stalls etc.

Andy

Need a fail safe on HP fuel pump, thats what the ECU supposedly does. If you prang with ignition on, your system leaves HP fuel feed!

Yes, that's what I feared. So if I tap into the same +12v feed out from the ECU that trips the OE fuel pump relay I should be OK? The inertia switch kills the earth to it so I'm not changing anything there

Andy

I would think so, unless its the ECU itself that's causing your? intermittancy. You have more faith in the inertia switch than I didn't even know it had one, mind you mine's a TDi, so FK what it has! If this bypass doesn't fix it maybe investigate that output from the ECU!

On or around Fri, 8 Jan 2010 09:57:33 -0000, "Andy" enlightened us thusly:

Have you tried running it for any length of time on the direct feed?

Could be. There's an earth wire from the tank unit to the chassis, check that too. ISTR you replaced the relay itself, you might try relpacing it again - I've had several occasions in the past where I've replaced a component with a new one, then spent about a month trying to trace another fault only to find that the new comonent had failed prematurely.

To feed a new relay yes. I doubt the ECU has enough switching capabilty to drive the pump direct, direct ECU to pump could well blow up the ECU...

I don't think you were thinking of goibg direct but just in case... B-)

On or around Sun, 10 Jan 2010 09:07:19 -0000, "Andy" enlightened us thusly:

yes, you do still need that, and yes it should work. As a first stage, I'd run a temporary new wire from the relay output to the tank, and see if that cures it. No point in a lot of effort if the fault turns out to be somewhere else.

Does the gauge behave correctly?

Are you sure the ECU puts out enough power to run a pump directly without a relay? I wouldn't think so, you may destroy it.

The inertia switch

Wasn't going to pump direct from ECU, would be via a relay but I think Austin you are right, I'll run a new feed from the existing relay output first.

Andy

Kev thinks there may be a bit of loom thats not happy.

Could link in to the burning rubber smell that I still get! Need a good poke around underneath when the weather improves.

Andy

The bloke i bought the alloys off today was on about the same smell & his was a BMW 4.4 V8 L322

I'm 99% fit now, we'll have a look next weekend if you want?