Right, just been out to set the CO on Cosnada. Base idle all set, fuel pressure 3.5 bar (no vac and plugged) etc etc.

I only have a Gunson gas tester but I have used one for years to tweak stuff and they are ok.

I started out with an initial reading of 9.7 So, I'm tweaking the pot on the ECU (L8 Green top with lambda / CL enabled). I have managed to get the CO down to 4.6 at its lowest but can't get it any lower. It just starts creeping up if I adjust any more. I try a little opposite direction on the pot to try and find the 'middle sweet spot' but couldn't.

Is this indicative of a knackered lambda sensor as I was hoping to get it down to about 1.5 CO.

Suggestions?

 

mine was like that mate i sent it to msd for setting up and it turned out to be the map sensor on mine

 

Any more ideas - no eureka moments.......... aha mate, ya aint plugged the fanny bracket into the laughin shaft.

Need to get aout and have another go. I will start off by resetting the pot on the ECU (not ECU reset).

 

if closed loop is enabled, how do you think twiddling a pot is going to help? the clue is in the question

 

I had the same problem with mine, turned out some numpty had wired the TPS the wrong way round

 

Can you elaborate - not sounding thick but if I have missed something then please let me know

All wiring is standard and not messed with - all 4x4 stuff e.g. TPS, loom, ECU etc

 

Mine is exactly the same as this with a L8 ECU.. All my sensors are fine. Will Pedley put all his fueling gear and IAW monitor on mine and managed to get it a bit lower than yours but my Global co screw on the ecu is pretty set to much minimum. I've got good AFR's all the way through though.

Edited to say mine is not currently running closed loop.

 

Okies but how do you get through an MOT? Thought it should be 3.5 or less for your age car? At least mine has a 4.5 level I think but miles from it and so got no chance on an MOT standard machine.

God knows what the HC reading is but all pre 92 are ok I think.

 

Managed to get mine down to 3 I think but it was a struggle. Is yours running closed loop?

 

It is yes but I have no cats in the exhaust - this is gonna kill my chances of a 1.5 utopian CO level. Just realised this douh If it was catted up then I would be getting much lower readings.

What do other Cossie users get as a CO reading on their modded cars?

 

Mine without closed loop runs below 2% CO, If it's that far out I doubt a cat will clean it up. I know without closed loop this could be down to map sensor.

 

Yes, second opinion on that - will have to try it out.

MSD say that I should see 2.75 - 3.0 and with CL enabled 1.5

 

I have 2wd so completely different setup I know, but I was having similar issues and it was a MAP sensor. My sensor was bought from Gary @ RS Classics and was clearly a new unfitted item so was last thing I thought of checking, but was also a non genuine item. Will only use a genuine sensor now.
cheeRS

 

3rd to state 3 bar now - I'm on the case and will report back when I have a spare

 

what does closed loop fuelling do?

it looks at the reading from the lambda sensor and adjusts the amount of fuel going into the engine until that output is where it wants to be.

if you adjust the global multiplier to put in more fuel, this will result in the output from the lambda sensor going up so the closed loop controller will just reduce the amount of fuel again until it was where it was before and the lambda sensor reads what it did before.

there should be instructions with your chip to say where the pot should be. put in that position and if your emissions are wrong then you have a problem somewhere that needs properly diagnosing, not just try and twiddle some knobs and hope to fix it.

 

IICR the instructions were something like 5 turns clockwise and 2 turns anti clockwise. I may have that wrong as I'm at work without the documents.
Going to try a different map sensor.

 

do you get what i'm saying about closed loop, or are you just going along with it? if you don't understand, say so, so that someone can clear it up for you.

 

The way the MSD software works you do have to set the CO2 screw on the ECU. I get what you are saying about the closed loop software overriding the screw as such. but for whatever reason this isn't that case with his setuo.

 

yes it is the case. you still have to set the global multiplier to the right place for the open loop conditions.

MSD software or original ford software, it's the same principle. the closed loop does not operate all of the time so the fuelling has to be right across the whole operating conditions contained within the map. the 'CO adjustment screw' multiplies all values in the map, so having it to far one way will mean not enough fuel at that point, and too far the other way will mean too much.

if closed loop is in operation, to some extent it doesn't matter what is in the map at that point (although the controller only has a certain authority, so cannot correct very far away from the base value) as it gets altered based on the feedback from the lambda sensor so can add more fuel or take fuel away as necessary.

so if you don't set the CO adjuster correctly for the base map as given in the instructions but twiddle it all the way one way to try and overcome a problem elsewhere, it may look like you have cured the problem at idle where the closed loop controller has run out of authority but it will cause you problems everywhere else.

 

I Do understand yes. I will do as per instructions and see how I get on the next time I get out to it. I will reset the pot. If no good I will look at other possibilities.

 

nice one

does Paul RS understand? sometimes i feel i write too much and it's not concise and clear enough