Hi all,

As title, can i use any knock sensor and splice into the original wiring, as they're very cheap on ebay at the moment.

I plan to relocate at the same time.

Thanks

Mark

9/10 it's the loom not the sensor. Notice the code 34 is "knock sensor circuit" not "knock sensor".

Yes, I had a look on Z1 and it said the same thing. Problem is I don't think I can get to the loom either haha. Id like to abandon the original (with its loom) and relocate a new one elsewhere.

Relocating is pointless, it will either fail to detect detonation or get false readings. OEM location or Bypass.

Surely bypassing still needs good wiring. If my wirings duff then it wont help. Can I get to it taking the plenum off. The egr is gone already

It's under the lower plenum. If the solenoids gone then maybe. Removing the lower plenum is a pita. Bear in mind if you choose to repair the loom it's not quite how you'd think. The cable from the ECU is a sheathed cable, this then splits into two cables at the connector plug. You cannot just cut and join, you will have to decide what you've got and potentially split and splice the cable. Then if you decide to bypass it you need a resistor.

Edited May 22, 20169 yr by Stephen

Yes I don't want to take the lower plenum off but if taking the upper off gives enough room I can do that. I need access to it even if its just for the loom. I'll try the resistor bypass for now untill I can source a sensor and loom. Or just leave it bypassed

I have a nose, I had a spare loom. Mines bypassed. Can't remember if I've binned it though. If I can find it, you can have it.

Surely bypassing still needs good wiring. If my wirings duff then it wont help. Can I get to it taking the plenum off. The egr is gone already

 

It depends where in the wiring the fault is. Usually its between the engine bay connector and the Knock sensor, so you just bypass it at the connector. You can also bypass it directly at the ECU.

That's great Stephen thanks. Although if it's fine to run without I'll bypass aswell.

I realise I've worded this wrong. I tested the wiring to the ECU and it was reading fine. So it's wiring to the sensor that's at fault.

I have consult and just read the codes. Sure enough 34. So I have erased that and I'll see if it's cured tomorrow or not. Hopefully it's only holding back because I've had it all disconnected recently.

 

Went to bypass the plug sensor today and found this broken wire. Same on the plug but tucked away. I know it says on other forums that this is on purpose. But it looks like a bodge to me. So I reconnected it. And the plug side was the same. So I connected that aswell. Still boosting at max 7. Stuck now

Do you still have code 34?

How are you regulating boost?

Ive not checked since but I had erased it before and got a nice code 55. I tried it and it still feels the same. Will check tonight.

Regulating boost purely by boost controller.

Something else to note is that the boost gauge on the dash is reading 14psi, after market gauge reading 7, but it feels no where near 14 psi.

Regulating boost purely by boost controller.

Something else to note is that the boost gauge on the dash is reading 14psi, after market gauge reading 7, but it feels no where near 14 psi.

 

Remember if your regulating boost by the controller you are circumventing the det sensors ability to reduce boost whenever code 34 is still present the ecu will be running a retarded 10 deg timing, hence the feeling of low power, boost alone does not give the power.

 

Jeff

Well thats what i thought. Ive taken away its ability to safe boost. So is it all in the timing. Its retarding timing because it cant reduce boost?

The cas seems to be central in its bolt holes if that helps.

Well thats what i thought. Ive taken away its ability to safe boost. So is it all in the timing. Its retarding timing because it cant reduce boost?

The cas seems to be central in its bolt holes if that helps.

 

The standard timing is 15 deg btdc the standard boost around 9 psi when the ecu see`s code 34 it closes the boost solenoids reducing bleed off, this increases boost on the actuator and so opens the waste gate sooner, you then have reduced boost normally around 5 psi.

 

At the same time the ecu reduces the ignition timing value by 10 deg, this means your now running only 5dtdc which is of course 10 deg retarded, which is designed to save an engine from detonation if bad petrol or over boost occurs.

 

As you have a boost controller fitted you are negating the boost level drop, however the ignition timing is still retarded so your boost controller can make more boost but the car will feel sluggish.

 

The position of the cas unit should only ever be checked / adjusted with a strobe light, the ConZult or any other diagnostic only see`s the predicted timing for the set parameters not the actual timing, also a cas unit been central does not mean its correct, cam belt stretch etc will effect it.

 

For testing purposes just fit a 1 meg ohm resister in place of the det sensor connector and check for clear code, take a drive and test for clear code again, if all ok I would then turn your boost controller down and reset it again.

 

Jeff

I see, great info.

I have also read that the knock sensor is ignored in higher revs anyway. So bypassing it doesnt seem a big issue to me.

Ill get a 1megaohm resistor ordered as i only have 300k's at the minute and give it a go.

Thanks

What wattage resistor am I to use for this bypass? I cant find that on the info for it.

Nevermind, found it, 0.5watt. Will report back when ive got it fitted,

Thanks

 

Consult on a cold engine. Code 34 kept recurring so it still is an issue.

Timing looked well off to me but did decrease to 25btdc as it warmed up

That won't show your actual timing, just what it's supposed to be. You have to check with a timing light.

 

You have deleted your Boost solenoids I take it?

Predicted ignition timing is high when cold that is normal, the reason your timing stays around 25 deg as it warms up is it looks to be an auto converted to manual and the neutral switch is not connected.

 

Jeff

Boost solenoids taken from the bay yes. Not electronically deleted.

That's interesting. My ecu has manual written on it. I just assumed it was a replacement not a conversion. V5 says manual

Do you have some pictures of your engine bay, there's a few tell tales.

Ill get some up tonight. What am I looking for?

Theres a few things im not sure if my last one had. Open brake pipe next to the booster, extra hose near the power steering pot.

Starting to sound like a factory manual that.

Tell tales inc, unless changed anyway;

Balance bar, has an extra tee off on the left

Clutch hard line that runs down the inner wing

Loom difference by the Hicas solenoid

Looking further,

In the inner wing, drivers side, there will be expansion tanks, an auto will have modifications to the loom.

If you lift the gear surround there's different connections that will be disused.

Lift the board covering the ecu's in the foot well and you will most likely see the auto ecu.

 

A common one is when you start the car the power light flashes on the right of the dash. There's plenty of ways to spot a converted car. I wouldn't worry too much though. Once converted you have a lower duration camshaft in TT autos (Na autos aren't) and a slightly smaller turbo. Just means you will start building boost further down and peak earlier, in reality this isn't particularly noticeable.