Dreaded detonation sensor issues...

[StigZXTT]

Hey guys,
Was wondering if anyone could give me ideas for what I should do about the detonation sensor on my Z32 TT. Very often lately I've been starting it from a cold start, driving it carefully until it seems to be warmed up (temp gauge is reading normal and oil pressure has dropped to normal levels), I go to give it some gas, and, it safety boosts.... Ugh.

It does not always do that, sometimes it gets full boost just fine after warming up, and if it does safety boost after I think it has warmed up from a cold start, restarting the engine resets it and it never safety boosts again at operating temp. I replaced the detonation sensor and sub-harness in spring of 2012 and re-located it to the top of the upper intake plenum (didn't/don't have the money for my mechanic to tear apart the engine to mount it in the factory location). So I mean, my detonation sensor or harness shouldn't be bad right? Since it's so new? I'm going to run ecu codes tomorrow morning but I'm expecting to pull a code 55 that everything's fine.

What do you guys think? I've heard of people bypassing the detonation sensor all together to erase the problem, but what's involved in doing that, how much should it cost, and is there really a risk of actually detonating if I'm running stock boost and my timing is alright?
Thanks for the advice guys!

[ThisIsSparTTa]

You sure you aren't actually encountering knock? That would be a legitimate reason to go into safety boost and safety mapping. It sounds feasible as your issue is intermittent. You wouldn't want to bypass that protection if thats the case...

[StigZXTT]

I mean I'm not hearing or feeling anything that would be knock, what symptoms should I look for? And like I said if it does safety boost, and I restart it, it never ever does it again basically that day cause the car is warmed up.

[StigZXTT]

So I had a chance to run codes, and I'm somehow pulling a code 34..... Great....

[nissanfreak12]

I mean I'm not hearing or feeling anything that would be knock, what symptoms should I look for? And like I said if it does safety boost, and I restart it, it never ever does it again basically that day cause the car is warmed up.

Detonation sounds like marbles in a coffee can, rx7 did that damn noise all the time. God I miss my rotary.

Knock has a distinct rhythmic sound, very slow. You can hear it usually from the bottom of engine.

Valve tap is faster, top of the engine.

[StigZXTT]

Then according to that my engine is running 100% fine.

[StigZXTT]

Just an update, it turned out that my subharness to sensor connector was loose and didn't have a consistent connection, put some electrical grease and tightened the wire on the plug and it fixed it! The car hasn't safety-boosted since.

[t.mcginley.jr]

Just an update, it turned out that my subharness to sensor connector was loose and didn't have a consistent connection, put some electrical grease and tightened the wire on the plug and it fixed it! The car hasn't safety-boosted since.

Awesome! Glad to hear it was just something simple. If it happens in the future, consider getting the Z1 upgraded KS harness, its like $20-25 and is a better design than the stock one, more waterproof/corrosion-proof etc.