Vagcom help needed asap

[PhilW]

Are you running a decat, maybe it was disconnected for that reason, but surely it would have to be put into the map, if the lambda is disconnected wouldnt it throw it into limp mode?

 

[m0rk]

the primary sensor shouldn't be disconnected though.....

 

[BlueR]

Hi, just want to say many thanks to Neil for popping round and helping out - was very decent of him.

Second to clear up some confusion, the lambda sensor has been disconnected because it has broken and needs replacing, however why would there be two lambda fault codes as only one is broken (disconnected one)

Also i have no cat on the car

 

[BlueR]

why would jabbasport disconnect it?

but the fault is the same as when I fault code checked it last year... I'll dig it out later

Also as you may or may not know i've had the new manifold, turbo and many other bits fitted to the car since then...although havent had the lambda changed.

Is there only one lambda or two on my car??

 

[davidol]

what turbo and manifold have you got?

 

[PhilW]

And you have 2 lambda sensors, one pre and one post cat. For a decat you have to have the post sensor disabled.

 

[NeilC]

what turbo and manifold have you got?

IHI with jabbasport special

I was wondering if it was the coilpacks could you swap them round to see if the misfire changed to a different cylinder (one of the packs new aint it?). Can you get it to misfire whilst revving on the drive before you try this tho.

 

[BlueR]

No, there isn't a new coil pack on it, it's just a "borrowed" one from Jabba, that was second hand as one of mine went down with mapping last week.

And yes it has IHI VF34 with Jabba manifold and has no cat. Was told the lambda sensor was broken (im not surprised after the old cracked manifold and running VERY rich) so it has been disconnected. Do the two faults refer to the one lambda sensor only?

I will order new coil packs next week but i'm not 100% convinced this is the problem

 

[BlueR]

IHI with jabbasport special

I was wondering if it was the coilpacks could you swap them round to see if the misfire changed to a different cylinder (one of the packs new aint it?). Can you get it to misfire whilst revving on the drive before you try this tho.

It's hard to tell when driving, well impossible, which cylinder is misfiring. It is definitely an intermittent fault. To the "normal" driver as a passenger i could drive at 30/40 and they would be oblivious to a problem as as a driver i can only feel it slightly missing when put under load. However, then suddenly the car will noticeably misfire under load jerking around and then make a shotgun bang out the exhaust followed by lots of other pops. Then suddenly it feels like normal again.

When it is bad the idle is hunting a lot and is all over the place and sounds very rough

 

[m0rk]

BlueR - if yours is like the other Jabba'd IHI cars - then the MAF isn't able to accurately read the inlet air flow, so it's relying on the primary lambda sensor to correct for the fuelling at idle. now if that's shot as well - then the car cannot control it's idling at all. it can't tell if it's overfuelling or underfuelling.

replace that sensor (the wires were burnt I recall due to the DP routing) and it should be better....

 

[BlueR]

BlueR - if yours is like the other Jabba'd IHI cars - then the MAF isn't able to accurately read the inlet air flow, so it's relying on the primary lambda sensor to correct for the fuelling at idle. now if that's shot as well - then the car cannot control it's idling at all. it can't tell if it's overfuelling or underfuelling.

replace that sensor (the wires were burnt I recall due to the DP routing) and it should be better....

Thanks, hear what your saying, however i've done 500 miles since the lambda has been disconnected and had no problems at all with the car and no misfire....yet suddenly 10 mins after i drive through a big puddle i get the problem. Too much of a conincidence to me.


Also was talking to my mate and remembered the car did this about a year ago when we were out , misfired on 2-3 cylinders, went to the cinema, 3 hours later came back and it was still doing the same thing, drove my mate home slowly and it suddenly cleared up and never happened again

 

[BlueR]

Well i drove the car round for about 30 mins last night and eventually it cleared up and stoppd misfiring

On the way to work this morning it was the same, driving normal and no misfire. However, feels like it isn't running 100% but the misfire and hesitating has definitely gone, yet it is still backfiring and popping more than usual