rough/mis-firing when driving when cold

[andy88]

yet another problem now which i cant figure out.

when the cars cold it will start and idle fine but as soon as you start to drive it looses power/misfires and jerks all over the place but if you stop it will return to idle and idle fine.

you have to let the car warm up for 3-4 mins then it will be fine and drive fine for the rest of the day.

so far in trying to sort this problem out, ive replaced the maf, coolant temp sensor, spark plugs for the bosch ones, fuel filter(got face full of petrol trying to change this lol),oil & filter, air filter.

have also cleaned all connectors i can see in the engine bay and cleaned all earths and the battery is only 7 months old.

i really dont know what todo to get this sorted and cant even sell the car with it behaving like this.

anyone got any idea what might be causing this, ive ran out of ideas

i will never buy a k11 again with the coil pack engine nothing but problems constantly

 

[r-reg-sr]

damp in dizzy cap?

 

[pollyp]

Its a coil pack zed

 

[andy88]

is there any easy way of testing the coil packs, although strange why it idles fine just wont drive when cold.

oh and the old spark plugs were serioulsy sooty, so the engines running rich

 

[pollyp]

Faulty o2 sensor?

 

[andy88]

now im really stumped on what todo to sort it, so far ive replaced the following

sparkplugs (bosch ones)
air flow sensor
coolant temp sensor
fuel filter
all 4 coil packs
02 sensor

all this and its still playing up, will idle fine when cold but when you drive it its holding back, starts to judder and backfires and pops from exhaust, it only does this when cold and if you leave it to idle and warm up for a few mins, it will then drive perfectly with full power.

whats left for me to change to sort it out?

 

[frank]

have you checked for any faultcodes andy ?

 

[andy88]

its not brough up any fault codes at all whilst it been doing this.

ive just changed the 02 sensor again and im now getting a code up p0131 so looks like ive got a fault with the 02 sensor ive just fitted or the wiring

 

[Helloween]

maybe insufficiant power to the injectors under load when in full running temp (overfueling)? = ECU fault?


J

 

[frank]

there should be 2 lambda sensors on yours andy

 

[andy88]

you sure theres 2 i can only see the 1 and the diagnostics says theres only 1, well im only getting readings/info for 1

 

[frank]

yeh, pre and post cat lambda,s on the coilpack ones

 

[andy88]

well im blind , there is readings for both sensors on the diagnostics program, only thing is all these readings mean nothing to me dont know what im looking for

with front sensor plugged in

with front sensor unplugged

 

[frank]

99% fueltrim does,nt sound right to me andy

 

[andy88]

youve lost me now, whats 99% fueltrim mean?

 

[frank]

youve lost me now, whats 99% fueltrim mean?

thats how much correction the ecu makes based on the feedback from the lambda i believe mate

 

[andy88]

so is this gonna be something serious/expensive to fix, as its 99% wether its plugged in or not.

could it be something simple like the wires to the lambda shorted together somewhere

 

[andy88]

ok now im ready to take a lighter to this car

when i hold the revs up around 3k rpm , im getting 'open loop fault' under the value for the fuel system status.

also im now only getting a voltage from the front 02 sensor for short period when first started, then i just get 0.00v and might get a voltage if i rev it.
ive check all the wires from the 02 sensor to the ecu and there all fine.

im completely clueless now as to what todo and dont know whats causing the high fuel trim

 

[andy88]

one last question then im giving up with it.

when its fully warmed up i get readings from the 02 sensor but as soon as you touch the throttle, i get no readings from it.
which sort of explains why when i took it for the mot the emissions where spot on at idle but when you revved it they went through the roof.

am i going to need a new ecu, cause the 02 sensor is new, theres no shorts/open circuits in the wiring from the 02 to ecu, yet im getting all these strange readings.

my head is cabbaged with all this

 

[frank]

my middle lambda wire reads .4v to .7v when cruising, 0v on lift, and .9v @ wot andy

 

[andy88]

whats wot mean?, keep seeing this being said when searching google not sure what it means

i get .5v when its idle when fully warm but goes to 0.0 when revved

 

[frank]

wide open throttle mate, and it should bounce between .4 and .7v every second or more if its closed looping properly

 

[andy88]

cheers will double check tomoz the wot,

i dont think its going into closed loop atall, on the diagnostics it never says closed loop, just open loop then when revved a few times, says open loop fault

 

[frank]

there are some voltmeter vids on my youtube channel andy (aelknarf)

 

[andy88]

cant find my multimeter so cant get readings direct off the o2 sensor but have been out in car with diagnostics to get voltage readings and when driving its 0.00v and when you let it idle it fluctuates between 0.460v-0.560v and nothing at wot either.

in the section where is says what loop its in it says open loop and then whilst driving it says open loop due to driving conditions, never goes in to closed loop.

so very confused, readings from sensor at idle just not when you touch throttle or drive

 

[andy88]

ok problem now sorted

i put a maf in out of a almera from scrappy, genuine nissan maf and had to solder the temp sensor on as almeras have this located elsewhere.
then went and put the old lambda sensor in and its running sweet again, ( runs and touchs wood).

so looks like the universal lambda sensor that was new was broke to begin with and the cheap ebay mafs aint much cop either

cheers for all the help frank