what should i set the CO to? on an exhaust analyser.

saff 4x4 dk greens stg3

i need to know what to set it to at idle, turned it down for the mot, as have idle problems.

also should i check it at another engine speed??

in theory if the engine is fully warmed, it shouldnt matter whether the iscv is plugged in. and does the throttle adjustment screw affect CO?

cheers guys

R

 

Trouble with adjusting it is the fuel will be adjusted over the entire map..

 

yeah its a global fuel adjuster not just a idle co trim

when up to temp the iscv should have no effect on idle speed as it should be shut.

 

Is that the screw on the ecu? It doesn't affect the whole map, its only the idle. We proved this a few weeks ago on my friends stage 3 4x4 saph.

 

Screw must be 'screwed' then

 

this is what i though. it just affectis the fuelling at idle.

the fuelling over the entire map as on the ECU itself

 

Afraid not pal, it adjusts the lot

 

how can you map for all engine speed load conditions, with just one screw.

and by that theory, if you have the 'correct' fuelling at idle, you will have the correct fuelling over the whole rev range

 

nope, it affected idle, not the rest of the rev range?

 

presumably you set the screw for your base idle,then adjust the values within the map for all conditions,i'm sure Stu or somebody will explain it better,but that pot is normally fitted with a tamper proof plug,presumably ford didn't want people messing with it

 

The screw is what we call a global modifier in as much as it adds a percentage to the entire fuel map.

If your engine is just borderline safe on boost, leaning the CO can and will destroy teh engine when flat out. The correct base position is in teh region of 5 turns clockwise and 2 turns anticlockwise to put you back in teh ballpark, but this is of course dependant on MANY MANY factors such as heads, cams, sensors, fuel pressure etc etc...

 

thats what i thought, at the minute i'm not driving my car on boost (def not flat out) as it was adjusted down for the mot and other reasons

its all standard, head cams, all sensors work etc.

so the car has to be adjusted on a rolling road? or is the 3% @ idle a ball park for CO? i have access to an analyser but cant do it live.......as such

 

Ask teh mapper of teh chip what the co should be, then set it. Job done.

 

looks like its time to call power engineering then



i can set this CO at idle then?

 

just spoke to power engineering and they said this screw is 'only for idle' and they just adjust it till the engine is 'happy' sounds and runs smooth.

they said the majority of the fuelling should be governed by the ECU map, map sensor and fuel pressure.

it may take a while to get this, and the iscv - high idle issues sorted

 

LOL. Now you have a problem dont you. ROFLOL.

 

as said, adjusting the screw will alter the mixture over all the rev range.take it to somebody who knows what there doing.try stu.

 

OMG......

i followed stu's instructions, 5 turns clock...2 turns anticlock. took me a while to figure that it is a potentiometer...

i was turning the thing for bloody ages with the engine off to get it in a closed position

also following SECS and Richm's instructions to check the tps. and guess what.......

it now runs....sweet....iscv is working as it should be!

just gotta get the co checked before i give it a bootfull.