NitrousB.I.G.

I have a 94 GSR engine that im running on Crome Pro. My problem is to do with the knock sensor pulling out up to 12 degrees of timing at the track with the stock p72 and p30 maps. Now here is the wierd part. I double checked the timing at the distributor it was ok (16 deg with jumper in). We then did some data logging on the street, made some adjustments to the map and had no knock reading. Thinking everything was ok we did a pull from 2nd to the beginning of 4th. In second everything was ok until a hard shift in to 3rd and the knock instantly started pulling 8 to 12 degrees out. After slowing down it was still pulling out timing (as much as 8degrees) just cruising around town at about 2500rpm. After about 10 minutes everything was fine again until I made a hard shift. The knock sensor pulls back the timing every time there is a hard shift and at the track as soon as I launch. Can some one tell me what the problem is or what to try.

slowcivic2k

How is your fuel delivery? Fuel pressure? and what mods are on the engine and what octane fuel do you use? Total timing should be around 30 degrees or so with a P30 map at WOT, and 38-44 at cruising speed.

NitrousB.I.G.

Air fuel ratio is 13.0 to 13.2 and timing is at 28 to 30 degrees at wot. Part throttle the timing is around 32 to 38 depending on throttle input. And everything works perfectly until there is a shock on the motor, like a launch or hard shift. Then it begins to pull back timing for about 10 minutes, eventually it goes back to normal and is good for a pull, then starts to pull back timing after a hard shift or hard launch.

slowcivic2k

might have a bad knock sensor, if its bad it may register a knock more severe than it really is, if you can get a hold of an extra, swap it on and see what it does..

bitek

knock sensor is the one located at the bottom of the IM right? its useless though... it only detects the "knock" of the fuel if its gettin low/hi octane..

slowcivic2k

No it doesn't, its a piezoelectric sensor that vibrates and produces a voltage based on vibration, you can run any octane you want, but if it knocks, it will pick it up. Old sensors tend to put out more than they should (also the reason that quartz clocks have trouble keeping time after a while.)

You and even hit the motor with something to produce a signal, even the A/C compressor will produce a knock from the clutches coming on.

NitrousB.I.G.

Any idea who makes a cheaper replacement knock sensor. Honda is around 150 and aftermarket like neihof is around the same. I am also wondering about the quality of aftermarket versus Honda. Any one with any experience with the after market. ps Thanks for all the help.

slowcivic2k

I would find a junkyard and make a pull, tell the guy at the door that its a $7 oil pressure switch.

bitek

very well said... thanks for that one...