Knock/DET sensor issues

I've had a problem with the knock sensor in my car for some time now, every now and then it would limit the boost and retard the timing as if it has detected DET. I would simply turn the ignition off then start the car back up again and it would be back to normal for a while.

I've currently had a new genuine Nissan knock sensor fitted but now the car seems to be constantly limited to 0.5 bar of boost like its in some kind of limp mode.

Does anyone have any suggestions what could be causing this? I'm sure the sensor is detecting false knock for some reason because it's been doing it for so long I would of run into issues by now if the engine was knocking.

Have you done a ecu check for codes to see if there's something else not happy bud

It's not showing any codes, I'm not sure since it's had the new knock sensor fitted because I haven't checked. I haven't got the car at the moment, it's at a garage so I can't check but it never threw up the code for the knock sensor before

How did you manage to get it off mate

Bones wrote:How did you manage to get it off mate

I've had my gearbox done so got em to swap it over wile the engine was out. I'd of never got it off otherwise haha

It's like a reunion bones n hardy

could actually be det to some extent or something else resonating & new sensor picks it up well.
could do with fuelling & ignition checked to be safe (what ecu, piggybacks you got !). All super simple things likes plugs, leads, dizzy cap, sensor connectors, fuel pressure & pump voltage want be checked too.
Also if got real old fuel in tank that could do with draining .

Mr B wrote:could actually be det to some extent or something else resonating & new sensor picks it up well.
could do with fuelling & ignition checked to be safe (what ecu, piggybacks you got !). All super simple things likes plugs, leads, dizzy cap, sensor connectors, fuel pressure & pump voltage want be checked too.
Also if got real old fuel in tank that could do with draining .

Cheers for that mate.
I don't think there's any major issue with feeling because I have a wide band but I'm not tuner so not sure exactly what numbers I should be seeing but it seems fine at WOT. Pump voltage and fuel pressure is something I've never checked. It's had new leads, plugs and distributor so shouldn't be a problem there. Never thought about draining the tank but I'm guessing it will be a ball ache lol

I've got a feeling this is going to cause me a real problem!

Voltage to pump and fuel pressure sounds a good place to start I suppose

I had thought about the possibility of something metallic touching the block making the sensor pick up false knock but can't think of anything that could be doing that

What exhaust have you got bill.... ????

I'm not even sure, think it's got a mongoose tip, standard downpipe but not sure what the centre section is. Stock elbow too