[bmwkev]

i have a slight misfire on my 320i and a bad overfuelling fault, i have done a compression test and all 6 cylinders are reading 170 psi so it looks like the engine is ok, also i have changed the airflow meter, the dizzy cap and rotor, and the spark plugs. on idle i get a misfire but as i accelerate it gets less but it constantly overfuels it is giving a reading of 9 on the c0 machine in the garage has anybody any ideas what it could be thanks. :frown

 

[steviec_lj]

Lambda sensor?

Could also be a faulty injector?

 

[bmwkev]

i was thinking injectors but would that make it misfire too?
il just tell you i havnt got a cat fitted either

 

[Slacker-ray]

Hi Kev,

have you had the codes read mate?

 

[Slacker-ray]

had something similar on my Bro's E30 325i and it turned out to be a split in one of the injector seals.

 

[bmwkev]

i had the codes read when i had the c0 checked and there wasnt any faults showing
could i use 325 injector rail on a 320 ?

 

[Slacker-ray]

i had the codes read when i had the c0 checked and there wasnt any faults showing

I would personally check for air leaks around the intake mate.............your symptoms do sound similar to that 325i, we got no error codes and it misfired on idle and occasionally on the road......looked high and low and discovered that one of the injector seals were split. changed all six seal, car ran spot on and idled great.

maybe worth a shot

have u checked for leaks at all mate?

 

[bmwkev]

no i havnt checked for air leaks only on the pipes and they seem ok

 

[Slacker-ray]

no i havnt checked for air leaks only on the pipes and they seem ok

I would try that route mate.........does the car back-fire at all, what about when on full throttle, drive ok?

 

[Ronnie]

Check the seals out but I would suspect the lambda sensor if it's the original one. I had a Renault Clio in for MOT that had ridiculous emissions and that was the Lambda sensor

 

[bmwkev]

i understand what you guys are saying but if i just go round changing everything on the engine i will have to find very deep pockets to finance it all, the car drives as it should with no backfires but does feel like its pulling back on me at around 30-40mph and i have to change gear to correct it and stop the jerking also i noticed that if i race the car it reaches redline in first gear very fast with not a lot of speed reached i dont know if this is right or connected to this fault.

 

[bmwkev]

slight update : i took the chassis number to bmw today and asked them if there should be a cat and lambda sensor on the car and they said by that chassis number there should be, well guess what my car doesnt have them fitted, now thinking back to when i bought the car i remember the guy saying to me that he bought the car with a knackered engine as he had a spare engine sitting around, then the head gasket went and he rebuilt the head so im wondering if he took them off and decatted the car i dont know which way to turn now , do i fit a ambda and cat or change the ecu for a non cat one ?

 

[Slacker-ray]

slight update : i took the chassis number to bmw today and asked them if there should be a cat and lambda sensor on the car and they said by that chassis number there should be, well guess what my car doesnt have them fitted, now thinking back to when i bought the car i remember the guy saying to me that he bought the car with a knackered engine as he had a spare engine sitting around, then the head gasket went and he rebuilt the head so im wondering if he took them off and decatted the car i dont know which way to turn now , do i fit a ambda and cat or change the ecu for a non cat one ?

If your car has no O2 sensor and is supposed to then the car wont run right mate..........what I mean is that it would be constantly in Limp mode. how are the emisions?

i would route around the engine bay and see if you can find the wiring connector for the O2 sensor......as for the cat- I wouldn't bother putting one on- don't need it on that year of car and if you do you'll end up losing a few horses.

 

[bmwkev]

the emissions are reading a 9 on the c0 machine which is almost pure fuel out the exhaust, iv looked on the car for any sign of a plug on the loom and on the drivers side flitch there is a round plug with 4 pins just hanging around the exhaust area, as for the cat i have no intentions of refitting one to the car saying that though if it does need the sensor then i will have to change the downpipe to accomodate the sensor, i dont know if this helps but the inside of the petrol flap says suitable for leaded or unleaded fuel.

 

[Slacker-ray]

the emissions are reading a 9 on the c0 machine which is almost pure fuel out the exhaust, iv looked on the car for any sign of a plug on the loom and on the drivers side flitch there is a round plug with 4 pins just hanging around the exhaust area, as for the cat i have no intentions of refitting one to the car saying that though if it does need the sensor then i will have to change the downpipe to accomodate the sensor, i dont know if this helps but the inside of the petrol flap says suitable for leaded or unleaded fuel.

there's your problem mate.......that round plug is the one for the O2 sensor, your car should have one inorder to run right.

You don't need to change the down pipe........you got a mig welder??

I would drill into the down pipe and weld an O2 Boss on there or even a suitable nut and then just screw a new O2 sensor in, plug it in and away you go.........you'll find that your car will idle alot better, run smoother around town and be more responsive at part throttle and the emisions will come right down.

Get it sorted mate:thumbsup

 

[bmwkev]

i dont suppose you know anybody that has a lambda sensor lying around do you ? i asked at bmw today and they are £138 which i dont have and my local bmw breakers havnt got any either.

 

[Slacker-ray]

i dont suppose you know anybody that has a lambda sensor lying around do you ? i asked at bmw today and they are £138 which i dont have and my local bmw breakers havnt got any either.

Call ECP for a direct replacement should set you back no more than 45 squids for a bosch unit:thumbsup

Or......try AllParts.......they seem to be cheaper than ECP especially when it comes to Bosch sensors.

 

[Slacker-ray]

Funny how a diagnostic did'nt kick out an O2 fault code:confused

 

[bmwkev]

no not 1 fault came up when it was read

 

[Slacker-ray]

no not 1 fault came up when it was read

Just out of curiosity Kev, which scanner did you use mate?