91 NA Z32 feels like its waiting for the power.

[14psiplease]

What do i mean by that you say. Well its my bros car and when he first got it it ran awesome now couple years later the car feels sluggish, when you take off it pulls for a half of second then feels like the the engine is making more noise than power and this is how it feels all the way to red line, if you hold the gas pedal (half way for instance) in place the car feels like this- push pedal down rpms clim then you feel like more noise than power and finally it "catches up" and some times the car stumbles when you first hit the gas pedal. And every now and then the car runs awesome like the day he got it, but this condition never last long or from start up to start up. I have ran codes and only poped up the knock sensor and sense this isn't a turbo i don't think that's causing any problems Ive also checked the timing so far-dead on at 15 degrees; all the injectors were recently replaced(last 5000 miles) from a reputable shop that know what there doing. I own a z31 so only so much can fail on that before it wont run at all so issues are easy to find but i think this is a little over my scope of knowledge( still stuck in sohc ahah). gas mileage is still good going from galveston texas to san antonio only takes 3/4 a tank and it idles smooth and starts up in a half a second even on cold starts. Anybody know what could be causing this "lag" condition? or any thing to check specifically. THnaks guys

[Oh Em Zee]

just a heads up, the knock sensor (common problem it seems) when either bad or sending signal detecting rod knock, will retard the timing several degrees in order to protect the engine. this will result in a loss of power upon acceleration.
I had the knock sensor code on my N\a, had it replaced, and did notice a power curve difference between 4-5.5k.
Before it felt like it would ease back at 4k, then kick back in after 5.5k. after getting my knock sensor replaced, it felt completely solid through powerband.
i dont want to say it's your problem, before you go out to buy a 130 dollar sensor and install that pain in the butt, but the codes may indicate your problem

[14psiplease]

does any body know what kind of signal is sent from the knock sensor ie is it a 1-5 volts or what kind of scale does it use? IM sure i can find what the spec on it is in the repair manuel but i dont own one. anybody know whaere to downlad it for free!

[evildky]

the ecu should shoot a code for the knock sensor, you pull the codes yet?

[Oh Em Zee]

he mentioned that the knock sensor was a code that came up. i don't know what the signal output voltage would be.

[14psiplease]

Will the computer ignore the knock sensor if i unplug it?

[evildky]

if you unplug the knock sensor the computer will automatically default into saftey mode, it's a failsafe, the computers sees a lack of a knock sensor as being a knock signal, same goes for most sensors

[14psiplease]

ok im just gona do the resistor mod and be done with it, this aint no turbo and everything else on this car is in good condition so im not worried about knock/detonation.

[DokkTekk]

^ Good luck!

[14psiplease]

Do i sense sarcasm? If this sounds like a major no no tell me, remind yall this isnt my car so i dont want my bro on my a** for ruining his car. Are z32 NA's high knock potential, i know my z31 NA didnt even come with a knock sensor from the factory, (I do understand the diffrence here between SOHC and DOHC)

[DokkTekk]

You are removing a safety feature that can very well save your engine from future damage. What if something does go wrong like a valve chipping/braking/burning from pre-ignition because the resistor is fooling the engine into thinking that everything is still ok when in reality it isn't . The ECU is suppose to react based on what the knock sensor is telling it and adjust timing accordingly to keep things safe but that doesn't happen because of your resistor mod.

[evildky]

the chance of needing the knck saftey on a stock NA is minimal, heck I'd have no problem bypassing it on a stock TT, even further none of my older heavily modified cars run knock, although I plan to add it

and the Z32 n/a did come form the factory with knock sensor, and all Z32's came with dohc's, the z31 got sohc's, are you sure you knwo the difference?

[14psiplease]

well put in the resistor and its smoother but the stumbels and bogs have become more apparent than before? question though. i checked the base timing before when the ecu was giving me the knock code and it was dead on at 20, so now that my ecu isnt getting the knock code would my base timing be thrown off of 20??? I think the answer is no but JC to make sure