Experiencing a poor idle on start up on my 2WD Stage 3 Saph.
It's not even related to being just when cold. If started when warm it often still dies instantly when the throttle isn't held.

Any ideas?

 

Most likely a sticky or gummed up ISCV.

 

The base idle is set mechanically, the ISCV can only raise the speed above this, it cannot go below, so I am assuming the base idle is set correctly? If not there may be an air leak.

Martin

 

Hmmmm, will give the ISCV a clean out first.

Actually idles perfectly after a few minutes running too.

 

sounds like its running rich to me get the co checked

 

It is running a lot lower boost than it should for stage 3 at the moment, this maybe add to the problem? Was set up previously for the proper amount, so maybe running rich because of that?

ooops, just noticed this is in the Escort page rather than Sierra one! Feel free to move it mods!

 

Running lower boost doesn't make a difference - it'll only add more fuel relative to manifold pressure. And at idle, there's no boost to think about anyway lol

Only way to tell if it is actually rich is to stick a lambda probe up its arse, and then the CO should be adjusted to the chip author's specification (but certainly below 3.5% at MOT time).

Idle mixture is mainly goverened by the coolant temperature, fuel pressure, and CO pot setting. If it's had the fuel pressure raised for "more power" (see if the tamperproof plug's still on the regulator) it'll be rich all over the shop. Best thing to do is get a basic setup done so that idle speed, boost pressure, fuel pressure and CO etc are all set properly.

 

My escos does this but only when its hot, i need to keep it above 1500rpm for about 5 seconds or it just cuts out. The base idle screw on mine is siezed solid so i cant see if it makes a difference, i dont think it would though as it ticks over fine

 

Do you have a cone filter, when hot and car is left they get a lot of heat around the engine filter, and it gets ingested when initially started weakening the mixture, also happens when idling when the fans come on as it blows the hot air around the bay.
tabetha

 

your base idle can effect this, but it would most probably need an increase in the crank decay mapping. it may not be noticed when cold because of the enrichment process.