High CO%

**Speedy** · 28-01-13, 18:14

It appears the problems are starting .................

CO is through the roof when revviing the Q4 any ideas/common issues before i start looking

Think it reached around 12.5% at 3000rpm

So appears to be running on neat petrol and nothing else

**Steve Webb** · 28-01-13, 18:52

What have you done with the car since its arrived with you?

And how long was it stood before it was shipped over?

Also I seem to remember that you said it was out of petrol when it arrived at the docks.

Initial thought, are the injectors gunked up after the tank ran dry. I would suggest you whip them out (

) and give them a good clean.

However due to the location I'd say stick a whole heap of injector cleaner in and give it an Italian tune for a start.

**Speedy** · 28-01-13, 19:00

Think it has been for sale since April last year so just parked up since then

So far i havent done anything ............except put fuel in it drive it 40 miles or so home and start ip up daily

Getting it registered shortly so will throw some cleaner in it and give it a damn good thrashing

**wrinx** · 28-01-13, 19:13

Map sensor???

wrinx

**Steve Webb** · 28-01-13, 19:46

I think all of the dodgy map sensors I've come across have ended up under reading. Same for the small bore hose issues. And a map sensor reading low for whatever reason, will end up with the engine running lean.

Worth checking though, as at least the map sensor is easy to get to.

**wrinx** · 28-01-13, 20:36

I haven't got a clue really, was just throwing something out there that affected fuelling.

With Speedy being a mechanic and asking for help, it must be bad!

wrinx

**Speedy** · 28-01-13, 20:43

Originally Posted by wrinx

I haven't got a clue really, was just throwing something out there that affected fuelling.

With Speedy being a mechanic and asking for help, it must be bad!

wrinx

TBH i havent had the time to lift the bonnet yet ................just wondered if there was a common failure before i started looking

I have more pressing issues to deal with

**Steve Webb** · 28-01-13, 21:00

Originally Posted by Speedy

common failure

Poor choice of words?

**Speedy** · 28-01-13, 21:28

Originally Posted by Steve Webb

Poor choice of words?

Realise that now

**alfa155chris** · 28-01-13, 22:39

Originally Posted by Speedy

TBH i havent had the time to lift the bonnet yet ................just wondered if there was a common failure before i started looking

I have more pressing issues to deal with

V6 gearbox

**SteveNZ** · 29-01-13, 22:40

O2 sensor and or cat

**Speedy** · 30-01-13, 18:20

Well i`ve took the plugs out and then fitted a new set .................. the right ones for it not what was in and its running a hell of a lot better now

**Speedy** · 11-02-13, 17:46

Also found the pipe for the boost gauge was split and drawing in air ..............

connected that back up and now the emmissions are down to normal

Is there a rough general setting for the CO potentiometer ?? on the old cars a guide was to screw the mixture screw right in then out 2 1/2 turns and the CO was about right

So is there a similar way to set the CO potentiometer as adjusting it isnt making much difference with the Cats fitted as there cleaning up whats coming out now

**the wombat** · 11-02-13, 20:47

Cats! Whats one of those then?

**Steve Webb** · 11-02-13, 21:17

Aye, the Q4 falls into a grey area, not on Vosa's list and produced between 92-96, end result is you can, if you know a good MOT bloke, get an MOT without them.
You need to make sure he tests the car on the Chassis number rather than just putting in the year of manufacturer. Or something like that, its been a while since I was at an MOT station.

**Speedy** · 11-02-13, 21:19

Originally Posted by the wombat

Cats! Whats one of those then?

They wont be there shortly .....................am slowly working my way through the car sorting everything as i go and when i get to the engine the camblet etc will be done and some de cats made

Just wondered if there was a factory preset for the CO potentiometer