Hi,

My (stage three) 2wd saff is in for it's MOT tomorrow and I'm worried that its going to fail on the emissions, I was thinking of marking the current position and then winding back the CO screw a bit..

What do you think? I take it I should be turning it anti clock wise? and how much?

Also, Idle is all over the shop sometimes and knowing my luck it'll start misbehaving whilst they've got it running.. Is the ISCV easy to remove and clean up?

Any help much appreciated.

Cheers,
Luke.

 

you can't really mark the position, cos there's more than one turn of the pot available. if you do adjust it (and i wouldn't unless you have to), then carefully count how many turns you make, and be carefult not to reach the end and damage it.

an erratic idle can also be caused by a too rich or too lean mixture (as well as a range of other faults), not necessarily just a dodgy iscv.

best to get it properly setup (by a pro with a wideband lambda sensor)

 

Thanks for the advice..Apreciated.

So you think I should just let it go through as it is?

The idle is fine most of the time, it occaisionally starts to drop and rise between 700 and 1100 I thought this was classic ICV stuff?

Cheers,
Luke.

 

yep, let it go through as is, even if you fail on that one thing, it will be a free retest. even better is if you are there at the time of the test and can change the pot. screw if necessary to pass the emissions.

the problem is, changing this screw affects the fuelling over the whole range of speed and boost, so if you are leaning it out for idle, you are also leaning it out under boost which could have disastrous affects. therefore, if you do have to lean it out at idle to pass the mot, make sure you wind it back up before boosting it.

but if you're not sure what you're doing, and cannot check with a proper wb lambda unit, it's better to leave it to a pro.

 

Well, It's gone in this morning, My dad dropped it off for me as I had to leave for work really early..
Fingers crossed.

If it does fail on emissions my mate who tunes nissan 200sx's has a wideband lambda - I'll get him to check it out for me.

I cleaned up the ICV and it idles like a dream now so that is cool

Thanks for your help mate.

 

cool. good luck, hope it gets through. let us know?