Knock sensor.

[projectgsr]

Ok this knock sensor thing is really starting to piss me off. I've had trouble with like 3 of them. I kept throwing a code 23 on my GSR a couple of weeks ago. But then when I changed the knock sensor and put a straight pipe on my car I stopped throwing that code. I didn't have any problems for almost 2 weeks but then again today on the freeway it went off again. It only seems to happen when I go really fast or when driving for a while. I'm beginning to think that it is the wiring. If you look at my wiring harness you can tell that it has been spliced and reconnected. It's been like that since the previous owner. Although most techs all tell me that nothing is wrong with the wiring I can't help but recall the word's of this one young Honda tech who mentioned to me that "the knock sensor wiring is such that it shouldn't be just spliced, it needs to be saudered professionally". Well I was wondering about the validity of that. Has anybody ever heard of such a thing. Also I know that knock sensors are a common problem with Honda/Acura. At least with GSR's right? So isn't there a simple sollution to this problem. I've had on tech. suggest using a VTEC controller to "bypass the knock sensor". Is that possible? Comment's, suggestion's?

[hxgaser]

Knock sensor senses vibration, or sign wave caused by the engine and retards timing once it senses the vibration. It usually works with plus minus 2 volts, but I am not sure what the exact tolerance is. But I know that exact voltage is important with the oxygen sensors and the oxygen sensor wiring should not be modified. But before fussing with the wiring try the following.

If the code is going off when you are driving fast and or on a long drive, it might actually be telling you that you have detonation. Chances of detonation increases with hard driving. A simple remedy might be trying higer octane gas. If you are not using high octane gas already, try going up a notch. It might help. The other option is to retard the timing.

I am not sure about using VTEC controller alone. By engaging VTEC earlier, I guess you dump more fuel earlier, but that would not necessarily solve the detonation issues.

Anyways, trying higher octane gas sure gives you less headache than trying to fuss with the wiring.

[projectgsr]

I always use 91 octane fuel. Either Chevron or 76. Do you think the fact that I have a JDM engine in a 95' USDM Integra GSR is why I would get detonation? Maybe the ecu I'm using isn't programmed for 10.6 comp. ratio. Does that make any sense?

[hxgaser]

Originally Posted by projectgsr

I always use 91 octane fuel. Either Chevron or 76. Do you think the fact that I have a JDM engine in a 95' USDM Integra GSR is why I would get detonation? Maybe the ecu I'm using isn't programmed for 10.6 comp. ratio. Does that make any sense?

10:1 vs 10.6:1 could be the problem, but before you venture into costly ECU modding, check your timing. It could just be that your ignition timing is off a bit? Retard your ignition timing, not your cam timing. I don't know what the actual timing value is, so you should look that up in the manual. Anyways, lets hypothetically say your timing value should be at 16 degrees BTDC. And you check the timing and it is at 16 degrees. So what to do you wonder? Well just retard the distributor by 1 or 2 degrees, making it 15 or 14 degrees BTDC. 1 or 2 degee changes are okay based on symtoms of the engine. See if this helps the issue.

Otherwise, I guess it could be your ECU, or wiring harness.

[projectgsr]

Thanks for the help. I am actually going to have my timing retarded a bit on Sunday. My new mechanic recommended the same thing. I do have to mention thought that last night I took my car to the track and ran the drag strip. But on the way there I used that NOS brand octane booster and filled up my tank about half way. I ran a 9.9 on my last run on the 1/8 mile and my check engine light didn't go off even once. So I think that stuff really works. But that also leads me to believe that your theory that I am actually getting detonation is correct. So I guess by retarding my timing I won't have to constantly be adding octane booster huh? Thanks again.

[hxgaser]

Hey, nice time. Anyways, yeah retarding timing should help and you won't have to put octane booster everytime you fill up the tank. See how your car runs after retarding the timing. I doubt that it will impact it negatively.

[superbluecivicsi]

knock cels are not caused by knocking itself. the knock cel is the operation of the cel itself. knock cel problems lie in the knock sensor, the wiring, or the ecu itself. if you already replaced the knock sensor, get a multimeter and put it to the wire

[projectgsr]

I know I am really late in answering this thread but I just couldn't resist. Sorry I've been really busy lately. Anyways it turned out to be my wiring the whole time. My mechanic checked the connector on the wire splice and he said that it pulled apart almost effortlessly. So instead of soldering it like I asked him to he just respliced it with this connector that he said act's as a solder (hope I spelled that right). He didn't charge me that much and it hasn't given my any problems in about 1 1/2 months. No more knock sensor codes. So that solved that problem. Now I just have to take care of my leaking radiator. Thanks everybody for all the help.

[hxgaser]

I was wondering what happened to that. It's always good to hear about how people worked out their problems, because I get to learn from it too. Thanks for posting.