Glenn_

iTrader: (1)

Hi there all. How many of you have adjusted the fuel mixter on your cossies so that they run rich. Is it harmful to the engine. Im just thinking cause my mot is due soon and i know its running rich from last time it got moted. I was thinking if its harmful i will just adjust it back to where it should be. I took it to a guy who does alot of modified cars and he set my cossie to run rich. What do you all think about this then. Shall i just leave it as it is. My car has been running sweet as it is.

tabetha

Depending on wether it is a very wild spec or not, 99% of them do not need to run so rich that they won't pass the MOT easily.
Mine runs around 2.5% perfectly and so should any apart from really wild cam ones they should all easily pass the emissions test.
tabetha

Glenn_

iTrader: (1)

So they dont have 2 run rich then. I thought it must of been a good thing. cause the bloke who adjusted it in the first place does performance cars. So does anyone reckonmend that when the mot is due shall i just adjust the co and put it back to where is should be then. If running to rich can this cause bore wash.

Glenn_

iTrader: (1)

My cossie is stage 2 with greens and a better actuator. Ive got a dyno graph from a few years ago before i bought the car and it says its running at 300 bhp. Should i just leave it or adjust it so that the emissions are normal.

Glenn_

iTrader: (1)

What do other people think about this. At the end of the day i just want my cossie to be right.

Miller 3

iTrader: (4)

I would not touch the co screw mate. Just get it set up then leave it be

Glenn_

iTrader: (1)

So i think it might be best to set the emissions up and leave it at that. I took it to this bloke when i first got the car cause i thought he knew what he was doing. Im a bit angry now with that bloke.

J9BBY

My local Ford dealer told m,e that the CO screw adjusted the mixture right though the rev range

Glenn_

iTrader: (1)

Like i said i just want my car to be right and i dont wanna fook the engine in any way. How are other peoples cossies set up.

Miller 3

iTrader: (4)

Glenn the best thing for you to do is get in contact with Stu from msd. You wont go anywere else ever again mate http://www.motorsport-developments.c...s/whoarewe.htm

Glenn_

iTrader: (1)

Thanks mate. I work in a garage so when its due the mot i can get it sorted. Im gonna get my car all set up next year hopefully. So for the time being i just want it to be right.

moonstone mike

mine co went off the scale

but runs sweet

AndyPen

iTrader: (24)

I run BD 14 and 15 cams on a T4 with greys and have 408bhp at the wheels. PJ motorsport were brilliant setting it up but as she ran so rich at idle they gave me an MOT chip as well.

Car is way more prone to stalling and you have to use the revs of course (with this fitted) but passed the MOT test with no probs.

Best get it set properly in my view mate. Have you pulled the plugs after a run and see how they look? Could it be like mine and only rich at low revs?

big mac

iTrader: (7)

If chip should b 2.5-3% at idle but unless you have afr meter you cant check load fuelling you need a set up to be safe

tabetha

Hairy cams as above can be a problem as they are so crap low down, there is just insuffecient air speed for decent fuel mixing so will run very rich low down.
The CO screw is a screw that adjust the TABLE of the idle mixture, this table ADDS to the main fuel table when on the over and the throttle is opened, it has an effect up to around 2000rpm or so, in a major way, but only because air flow is so minimal.
It's significance as a percentage of the overall total when under boost or higher speeds is just that a minimal percentage now of the OVERALL flow.
If you think of how much air your idle speed control valve can pass due to it's small size, this is easily enough to hit 6000rpm at idle, now compare it to the size of the hole that the throttle butterfly leaves and you get the picture!!
Unless it has very hairy cams, it will still pass the MOT without alteration, even with greys, it is a total falacy that they need to be adjusted to pass each year then reset to run properly.
tabetha

big mac

iTrader: (7)

Tabetha what is a hairy cam? Or should that be lairy lol good explaination though m8

tabetha

Hairy/lairy, one with a more pronounced lift or duration, ie a performance one.
tabetha

big mac

iTrader: (7)

Got you m8 just had a funny pic in my head! Lol

Glenn_

iTrader: (1)

Well i think i will leave it as it is till the mot then get it though its mot and then put it back to where sunning rich. I will have to get it set up next year. It runs sweet with the fueling been rich.