Problems with my R8 - Help Please!!

[stubbsey]

Hi all

Hoping you maybe able to help me with this.

My car has just developed a problem today - doesn't want to start straight away, then when it does (apart from the obvious over petrol smell!!) the revs stay high even when driving and will not drop down to normal tick-over.

Coughs and bangs a bit, then after a short run it clears and the revs drop back down to normal

it will start normally a couple of times, then the staring issue is back.

during this (and may not be related) the temp gauge drops right down to nothing, then comes back to normal when the revs drop down.

Nothing seems to have become disconnected as far as I can see

Any ideas / help greatly appreciated!!

[preciousmetal]

Battery ? Check charge and voltage on dash info

[r8black]

Similar symptoms too mine a while ago
HT lead was braking down
New leads all sorted

[stubbsey]

Battery all good mate - not dropping a cylinder and HT leads are pretty new

[k20erham]

Hi coolent temp sensor,or wiring, over fueling just like you suspect, as soon as the ecu see's (correct) engine temp it runs and starts fine?

[stubbsey]

Indeed - so what do you suspect?

[snowwolf]

It is a worry when things are not right, my old Monaro seems to have a similar problem, it runs ok but when he come to a junction it will stall or idle very low revs, most times it is ok but then has a phase of playing up, he has put a new battery on but no different.
Hope you can sort yours out

[Dave3166]

We had a similar problem with an Audi we owned a while ago, a 1.8 Turbo Petrol.

Started revving by itself every time we stopped at traffic lights & engine idling, also didn't seem to start very easy at the time if i recall, long time ago now.

Investigated the problem with goggle, turned out to be the EGR Valve, i replaced it, all was fine then.

This may help or be no bloody help at all, as i`m no mechanic

Just thought i would mention it anyway, hope you get the problem sorted soon.

I don`t even no if these cars have an EGR Valve

[k20erham]

HI, PUT A COOLENT TEMP SENSOR IN IT, not the temp gauge sender, the ECU fuels from a stand alone sensor, it looks like a temp gauge sender, some are acutally coloured blue.

[KMud]

I had an intermittent bad contact on my engine coolant temp sensor, and when it broke contact it thought it was ~-34'C so would go pig rich and buck/stall...luckily between the wideband O2 and EFI live log it was an easy diagnosis.

[stubbsey]

KMud said:

I had an intermittent bad contact on my engine coolant temp sensor, and when it broke contact it thought it was ~-34'C so would go pig rich and buck/stall...luckily between the wideband O2 and EFI live log it was an easy diagnosis.

Interesting mate - explain how you sorted it out!

[stubbsey]

any one else?

[stubbsey]

With a bit of wiring un-plus and plug back in - tidy and clean up the R8 seems to be running just fine again!!
After 7 years of driving these cars they still baffle me!!