Random cylinder msifire

[Mike-]

Evening lads. Got a 2001 saxo vtr turbo here.

When the car starts up, it runs on all 4 cylinders then after 10 seconds or so it drops down too 3.
If i clear the fault from the ECU it then goes back to running on all 4 cylinders but then after another 10 seconds or so it drops back down to 3.

So far the Coil pack, Sparkplugs, MAP sensor, ICV sensor?
Have all been changed.

We unplugged the lambda sensor and it made no difference, no engine management light or anything?

Its also blowing air from the oil breather, not sure if this is a problem or not.

Car is on about 103k, serviced about 4000 miles ago, I.E cambelt, plugs oil the works.

Could anyone enlighten me on what my problem is?


Cheers


Mike-

[stevo67]

What condition was the lambda sensor in IE a sooty colour?(indicating overfueling)

[Mango_Wes]

Same thing was going on with me, changed my Coil pack last night, and so far so good!

[greyjasper51]

Its a severe fault then... Im thinking valve seats...

What turbo setup you running cus if its running lean it will start to burn the seat edges...

What cylinder dies?

[Mike-]

What condition was the lambda sensor in IE a sooty colour?(indicating overfueling)


Going to change the lambda sensor on monday hopefully thats the problem, its the only thing we havnt changed.



As for the set up, its a T2 turbo running 9 psi, 406 injectors, Standard ecu, Standard fuel pump

It had been fine for 3 weeks or so on this set up

Dont know what cylinder, its a 0300 code so random misfire.

cheers


Mike-

[greyjasper51]

Dont spose youve compresion tested it?

[blackie_2k5]

remove the spark plugs and post up pics of each one

[Mike-]

spark plugs are brand new mate, litterally put them in last night, compression test will happen monday, as i've just had to buy a compression tester lol.

If its not the lambda, ill post pics of the sparks up on monday, the cars still at rorz's

Is it just me that finds is weird that when clear the error codes it jumps back to 4 cylinders, i can do this over and over again it will go back to 4 then back to 3, ect.

[blackie_2k5]

wanted to see the colour off the plugs as your not running a mapped ecu

it sounds like a fried map sensor or lamdba or something stupid like that,

once the error is cleared its coming back as soon as it reads info from which ever sensor is at fault

you have tried another coil pack yeah?

[Mike-]

Yeah mate, used 2 coil packs, also used 2 map and 2 icv sensors aswell

the only thing is we havent changed is the lambda sensor so hopefully, fingers crossed that this is the problem

I only ask about the code being cleared is just so i can rule out duff pistons? surely if it was pistons it wouldnt go back to running on 4 would it?

[blackie_2k5]

sounds liek something to do with start up enrichment

[Mike-]

Do you mind explaining in a bit more detail please mate?