co idle mixture - discussion

[Apsogos]

Good morning,
i want to ask about co idle mixture.
specs : 4age 16v european second generaton tvis engine.(no catalytic converter)
Freshly rebuilded.Before the rebuild the co mixture was set to about 1.38%

After the rebuild on 2000kms, i replace the fuel pump , i cleaned the injectors, i replace the igniter, fuel pump internal and external filter and i reset the ecu.

Now i have 3000kms.Few days before i went to my mechanic to check the CO and was at 6% !!!
a)how that happends?when i changed the fuel pump or cleaned the injectors maybe something changed?
b)We adjusted again the co to about 1.7% , here in Greece is a hot summer so the fan opened every minute at most at the procedure and was difficult to adjust right.
as the engine worked the co was moving from 1.20 to about 1.80.Is this right?meaning should it be stable as the engine working to a value ? eg to 1.5% ?

thank you

[fax0815]

Sounds to my like that during changes on the fuel system, your engine is getting a lot more fuel than before, hence the higher CO. Could have been things like block filter, lazy fuel pump,... nothing to worry about.

Setting the CO up with an unstabe ilde is kinda tricky, but as long as your´re in the factory specs (sorry can´t remember them right now!!)and the tolerance range I whouldn´t worry to much.

You can allways receck it maybe at night or early in the morning is colder outside, or disconect the fan for the time of the procedure?

[Apsogos]

fax0815 Wrote:Sounds to my like that during changes on the fuel system, your engine is getting a lot more fuel than before, hence the higher CO. Could have been things like block filter, lazy fuel pump,... nothing to worry about.

Setting the CO up with an unstabe ilde is kinda tricky, but as long as your´re in the factory specs (sorry can´t remember them right now!!)and the tolerance range I whouldn´t worry to much.

You can allways receck it maybe at night or early in the morning is colder outside, or disconect the fan for the time of the procedure?

hello my friend! thank you for your fast reply....i dont have unstable idle..
i have unstable co,meaning e.g from 1,85 % to 1,20% and then circle again.... the oem settings are 1.5% + - 0,5% ,my resistor is new , i replaced it 2 years ago.

p.s. unfortunately i cant check it anytime i want because i dont have a CO analyzer at home. .I should go again to a shop to check it again.(i was thinking if there are cheap portable co analyzers to buy ? )

[fax0815]

Hi
I understand the problem, but you were saying something about your fan.

So in thought during the heat the fan turns on a lot and therefore the idle changes due the load on the alternator? That whould be not so good for setting up the CO as it should be ideling without load or any reving for a couple of minutes before you start settin it up. I think even the manual says that all ancillaries should be turned off.

Anyway you are within the settings! I´ve looked at my old tests it was never on the 1,5 there was always a little up and down.

I´d personally whouldn´t bother, just test it again, if its still within the specs its fine.

Don´t thing proper testers are cheap to buy...

[Apsogos]

fax0815 Wrote:Hi
I understand the problem, but you were saying something about your fan.

So in thought during the heat the fan turns on a lot and therefore the idle changes due the load on the alternator? That whould be not so good for setting up the CO as it should be ideling without load or any reving for a couple of minutes before you start settin it up. I think even the manual says that all ancillaries should be turned off.

Anyway you are within the settings! I´ve looked at my old tests it was never on the 1,5 there was always a little up and down.

I´d personally whouldn´t bother, just test it again, if its still within the specs its fine.

Don´t thing proper testers are cheap to buy...

Good morning!
yes yes the radiator far , was working minute by minute so the CO didnt have the time to stabilize?(thats what you mean i suppose)
I don t know if you have understand, by i am emotionaly connect with her and i want to be very accurate with my moves!
I suppose you are in love with yours too ah?

P.S. I will leave it work a litle these days and one day that the temperature will be colder, i ll go again for measuning the CO.

[fax0815]

Apsogos Wrote:yes yes the radiator far , was working minute by minute so the CO didnt have the time to stabilize?

This! Disconnect the fan while you´re doing the CO adjusting.

[Apsogos]

fax0815 Wrote:

Apsogos Wrote:yes yes the radiator far , was working minute by minute so the CO didnt have the time to stabilize?

This! Disconnect the fan while you´re doing the CO adjusting.

if i disconnect the fan with the specific temperature, the temp will go above 90!!!
i don t want my engine to baptize in fire!

[fax0815]

100°C is still nothing to worry about.

[Apsogos]

a friend told me to disconnect the idle up valve..so the engine when the fan would not rise the rpms....

[Andrax]

Its normal that the CO values are not stable. The ECU is always trying to adjust it, so you wont get a linear value. As said, set it on the factory specs. Anyway, after a few kilometers it will get out of specs again...