2001 y reg c70 2.0 LPT missfire. Please help

**rebmulp** · Monday 31st May 2010, 22:00

Hi,

My friends 2001 y reg c70 2.0 LPT has suddenly developed a missfire and appears to be spitting unburnt fuel from the exhaust with white smoke. Coil packs seem to be sparking, plugs are sooty. We suspect incorrect timing of spark. Car has had no previous mechanical issues this has literally just started without any previous missing or idling issues. We have been trying to locat thje top dead centre sensor to no avail! Any one had any similar issues ?? Any help would be greatly appreciated.

Thanks

**rebmulp** · Wednesday 2nd June 2010, 15:01

Put code reader toit and it seems it needs new injector anyone know how to change one? Any help gratefully received

**Dacvolvo** · Wednesday 2nd June 2010, 23:33

Hey Bud

Well at least you know where to concentrate on. There's nothing more frustrating that not knowing what's causing the problem and having to end up replacing sensor after sensor and parting with lots of cash to try and isolate the fault.

Where is your friend based?

**Wobbly Dave** · Thursday 3rd June 2010, 00:46

I'm putting my money on coil packs or faulty injectors.

**The Baker** · Friday 4th June 2010, 12:55

Guys,

It's my c70 am also based in Lancashire like rebmulp. The plot thickens ! So far, new injector fitted and it's still pulling up P0204 Cylinder 4 injector circuit low fault. We have tested the resistance on all 5 injector wirinigs and cylinder 4 is grounding to earth. Hopefully will have this sorted today as our friend who is a mechanic is going to have a look at the wiring today but could be a fault on the pcm. Does anyone have or know where i can get a wiring diagram for the engine bay online??

Thanks for your replys so far and cheers rebmulp for starting the thread, have remembered my username and password now !!

**rebmulp** · Monday 7th June 2010, 20:00

If injector is disconnected electrically it runs on 4 cylinders but when connected it overfuels horrendously . Suspect ecu is sendiing incorrect signal any ideas?

**The Baker** · Wednesday 16th June 2010, 12:17

ITS FIXED!! It turned out that a capacitor had blown in the ECU shorting it to earth, new capacitor fitted, car is fine once again. Thanks for all your comments

**Al115** · Wednesday 16th June 2010, 12:49

How on earth did you track that down?!??

**Wobbly Dave** · Wednesday 16th June 2010, 13:38

Originally Posted by Al115

How on earth did you track that down?!??

That's gotta be a 1 off - I am sure.

**The Baker** · Wednesday 23rd June 2010, 07:21

It was a long evening tracing feeds on the circuit board !!! Fortunatly I know a guy who is amazing when it comes to microelectronics!! Had to slightly butcher the ecu as the capacitors were impossible to get to. However if it went to Volvo it would have just been a new ECU !