Hi All,
Already posted this in General technical but didn’t get much response. My car is proving a nightmare to tick over when cold. It starts fine every time, but immediately goes into lumpy idle with revs all over the place, and then stalls. If I keep my foot on the throttle slightly until it warms up, the tick-over settles down, but I still get a slight miss if I blip the throttle even then. I’m pretty sure the lambda is on its way out anyway, but could this be the cause of the problem? I’ve got an Apexi with commander and the readout of the sensors indicates the o2 is running at 2.68v which, from what I can tell via some of the threads across the board is probably too high. Would a broken lambda sensor cause this type of problem? Car is a JDM STI6 by the way.Thanks for any help you could provide.

Simon

 

Anyone help here guys? This is really starting to bug me now! I've changed the o2 sensor and the MAF sensor. Also cleaned the idle control valve. It's definately not the temperature sensor as the fans don't come on when i start the car. Got no fookin idea to be honest. Arrrgghhhhhh! Puleeeease, someone help.

Simon

 

clean TPS ? clean inside throttle house around the butterfly

leak somehwere ?
just a few suggestions

 

Thanks Reggie. I'll go and give it a check over for leaks now. (it'll have a bastid leak in a second. If it keeps on acting up like this, i'm gonna bash the **** out of it with a hammer). Cheers
Simon

 

AFAIK Lambda voltage is supposed to be somewhere between 0 and 1v. 2.68v sounds wrong, unless the Apexi scales it in some way. See if you can borrow an AFR meter from somewhere or get a decent voltmeter and look at the actual reading the Lambda sensor is giving. Could be you have a dodgy earth on the sensor?

 

Graz, thanks for the reply mate. I've changed the lambda sensor since my first post, and the voltage is down to normal (rocks between 0 and .80v), so i've pretty much ruled the lambda out (unless someone tells me differently). I can't see any obvious leaks in the pipework either. It's really proving a b!tch tbh. Starts fine, idles terribly then cuts out time and time again until the engine is up to temp. The problem hasn't improved despite the sensors I've changed, valves i've cleaned, knuckles I've grazed and expletives I've uttered!