What should CO be at idle for a G60

[olly elworthy 0]

just had me mot and my CO at idle is about 0.68, is this too lean? :?:

[MoonlightVR 0]

Cat fitted or not?

if not I'd say it is a touch lean. 1% normally??

[olly elworthy 0]

got cat bypass fitted,,, ill richen her up a little in that case,, thanks,, (got co pot at 450 at the mo,,, )

[brian g60 corrado 0]

can i ask which way richens and wich way weakens .is lower reading richer or weaker ect.

cheers.

brian.

[steveo29 0]

i had a play on the c/o tester at work...mine is around 0.3 with out a cat....any amount of fiddling the co pot wouldnt change it

i think the ecu alters it to stay at a given value??

[beavis 0]

Lower resistance values (e.g.200ohms) = richer mixture Clockwise

Higher values (1000ohms) = Leaner Anti clockwise

 

Most cars fall between 400-700 ohms as a benchmark to get the AFR to the desired 14:1 at idel. I'd leave your CO pots well alone if you have no montioring gas equipment to hand.

It is a good idea though to test across pins 1 and 3 of the CO pot to check that your restance values fall between the above parameters.

steveo29, It sounds as if your CO pot could be up the spout, adjust the CO pot and see if it actually changes the resistance across the pins.

[steveo29 0]

beavis....yes ajusting the screw changes the ohm reading on the outer pin......didnt seem to make my c/o differant

 

can you advise on using a gas analiser??? i have access to one where i work(im a car painter not mech)..whats the procedure?? blue temp sender disc?? rev to 3k etc??? :roll: :roll: what shoul i set it too?? it seemed to be around 0.3 with everything hooked up

[stevemac 0]

whats the procedure?? blue temp sender disc?? rev to 3k etc??? :roll: :roll: what shoul i set it too??

AFAIK - c/o is usually set with the engine at idle & with everything connected. You may be confusing this with the proceedure for setting the timing.

[W3RKD 0]

whats the procedure?? blue temp sender disc?? rev to 3k etc??? :roll: :roll: what shoul i set it too??

AFAIK - c/o is usually set with the engine at idle & with everything connected. You may be confusing this with the proceedure for setting the timing.

 

correctomondo there steve... :salute:

[stevemac 0]

correctomondo there steve... :salute:

Cheers Daz :notworthy:

[beavis 0]

Yep, everything connnected. The CO pot just adjusts the base setting of the sender so the ECU is ignorant to the fact that you are adjusting the value of the sender manually and just sences a change in resistance so adjusts CO accoringly. I've never used a gas anoliser in my life, we just set everything on AFR ratios using our wideband probe, the 14.7:1 AFR ratio at idel/low rpm no load, on a car which alll senders are functional ensures a MOT pass in all cases. Usally MOT emmisons failures on G60's are due to a failed sender or excessive oil being burned when charger seals are on their way out.

[brian g60 corrado 0]

o.k. so if you have a cat fitted what would you normally set the pot to (in resistance).i say this as did have cat removed .

but now have the cat back on ,but may remove again in the future.or would it be poss to put up advised settings for both

with and without cats as a bench mark.

thanks.

brian.

[nikosg60 0]

Hi Guys.

 

Refereing to the original service manual the co adjastmuntmust be done with the blue temp sensor disconected.The steps of the basic timing setup on Digifant1 ECU are as follows:

 

1.Disconect the blue temp sensor

2.Disconect the crankcase breather hose

3.Adjust timing @ 6deg +-1

4.Adjust the idle screw on the back of the inlet manifold

5.Adjust the co and check the readings

6.Reconect the blue temp sensor and check the co again to be on the same values.

 

All the above are the basic settings of the PG Engine with Digifant 1ECU.

It is true that 400-600ohm is the best value on the co measured from pin 1-3.

 

Greetings from Athens.

 

NICK

[stevemac 0]

nikosg60, That is the proceedure for setting the timing & not the proceedure for setting the c/o when the timing is known to be correct. The c/o must always have it's adjustment done with all sensors connected. :wink:

[nikosg60 0]

No Dear,i am afraid your wrong.Except all the original service manual i have the Volkswagen training video for dealers.

It has this issue regarding to basic settings of this engine.

You have to make all the adjustments with the blue temp sensor disconected and after that you see what you get. :wink:

Its clear.This is the right way for sure.

 

Cheers

Nick

[stevemac 0]

nikosg60, Well excuse me matey

 

Here in the UK, we have an annual MOT test. The legal c/o emissions are tested by a department of transport certified testing station with ALL sensors connected. :shock:

[nikosg60 0]

Ignition timing,Co content and idle speed RPM´s are inter-related and must be checked/adjusted together.

Of course ALL sensors must be connected during the MOT test.

During the adjustment the blue temp sensor must be disconected.

You have an email in which you can read about this.Check it and will see who is right and who is wrong. 8)

[beavis 0]

I agree with the blue temp sender being off for ignition timing adjustment as in this mode all ECU ignition advance correction is removed which is imperative to accuratly setting the base settings. Ignition advance and CO are very much interelated from the aspect of when you adjust ignition advanc/retard this ultimatly affects CO/AFR readings so thefore the CO pot has to be adjusted to compensate. As far as removing the CO pot to set the CO mixture i'd have to disagree. With blue tempreture sender unpluged the car runs a lot leaner, typically 17-19:1 AFR assuming the car is running the desired 14.7:1 AFR with the sender plugged in. Therfore if you were to adjust the AFR to 14.7:1 with blue plug disconnested you would (do) see very rich AFR such as 11-12:1 AFR with the sender plugged back in.

The CO potentiometers adjustment is basically just the base adjustment of the air temp senders resistance, the ECU detects changes in resistance, but is ignorant to whether they be manual or actuated by change in tempreture across the sensor.

Is it a dodgy American training Video? I think the most important thing to note here is that CO and ignition timing are interelated and should be set together, but to ultimatly get the desired CO/AFR readings the CO has to be set with temp sender ON. I know this may go aganinct the grain of what VW video might say, but this is how you get the desired CO reading. I know that if you do it the way that VW describe with the adjustining the CO with the plug off thhe overall effect is that you end up with a car that runs pig rich when you plug the sender back in. The AFR gauge reads the truth so i'll follow that over VAG info.

[nikosg60 0]

Hi Beavis i dont wanna disagree with anyone here i am just adding some infos.This procedure i am talking except the vw videos, is also writen in Bentley official factory repair manual.

 

IT GOES LIKE THIS:

 

Idle speed and Co content,checking/adjusting

 

The oxygen sensor remains connected during checking adjusting.

Requirements

*Engine oil temp 80c minimum

*all electrical consumers switched off(do not take measurements while radiator cooling fan is running)

*A/c switched off

*Ignition timing OK

*Idle stabilizer valve OK

 

CHECKING ADJUSTING

 

*Switch off ignition

*Connect vag 1367 engine tester using inductive

*pick up Vag 1367/8 on ignition coil high tension lead

*connect SUN 105 CO tester(or epa approved equivalent)

*disconnect crankcase ventilation hose from emission control valve (arrow 1) and route such that only fresh air is drown in

*Start engine and let idle

*Will run from 1-4 min at increased engine speed

when idle is redused approx.100rpm

*DISCONNECT BLUE COOLANT TEMPERATURE SENSOR HARNESS CONNECTOR

*raise engine speed in excess of 3000 rpm 3 times then let idle

*Check idle speed and CO content

idle speed must be 800rpm +- 50rpm

Co content must be 0.7+- 0.4 volume%

IF NO

 

*adjust by alternately turning adjustment screws until both spec are obtained

*RECONNECT BLUE TEMP SENSOR

*Raise engine speed 3 times and then let idle

*Check CO content

must be 0.7 +-0.4 volume %

If No check OXS control.

 

Hope that helps :wink:

[beavis 0]

I'm not disagreeing, but there are more than one way to skin a cat. We too have a copy of the Bentley manual which is a wealth of information. Many procedures must be adeared to to get the correct results, other prodedures in it are very longwinded and over complicate simple procedures. All cars we set up pass MOT emmisions within the factory spec so the overalll goal is achived. The bentley and VW workshop manuals also say to condem a Supercharger if it is not Boosting to factory spec's :wink: