Bartman Posted June 27, 2006 Share Posted June 27, 2006 So I went ahead and purchased a cable and downloaded TTS DataMaster. It worked great and I went ahead and recorded a test run of a little over a minute. I just started it up, let it idle a little bit, and revved it a little. Well DTC Code Number 43 is set, which is the Knock Sensor Circuit. Tim (the PO) had already put in a inline resistor in the wiring, but that may not be enough with all the upgrades I recently completed. I'm thinking that I should install an LT4 Knock Sensor Module, which seems to be a pretty common upgrade for upgraded LT1's to prevent the computer from pulling out excessive timing. Anyone else with an LT1 installed one of these LT4 sensors? In the short little recording I made the spark was retarded a good 12 - 13 degrees when the engine was revving. Is this normal or excessive? Quote Link to comment Share on other sites More sharing options...
jbc3 Posted June 27, 2006 Share Posted June 27, 2006 Is the KS installed? You get that code when the KS is disconnected or not grounded properly. If the code is set, the computer pulls timing all the time. If the resistor solution you are talking about is not grounded properly, it will also set a code. The LT4 KS will help only if you are getting excessive valve train noise. Jody Quote Link to comment Share on other sites More sharing options...
Bartman Posted June 27, 2006 Author Share Posted June 27, 2006 Is the KS installed? You get that code when the KS is disconnected or not grounded properly. If the code is set' date=' the computer pulls timing all the time.If the resistor solution you are talking about is not grounded properly, it will also set a code. The LT4 KS will help only if you are getting excessive valve train noise. Jody[/quote']The KS is installed. I'm not sure if the resistor is grounded, but if I go with the LT4 Knock Sensor module I will remove the resistor. From what I've read a noisy valvetrain and headers will set off false knock. The LT4 engine is a normally "noiser" engine due in part to roller rockers in the valvetrain (I now have roller rockers as well). It also appears that engineers did a much better job on the LT4 KM to "listen" for true knock and to weed out the normal engine noises. Either way I still need to determine why code 43 is being set. I'll have to do some additional investigation. Quote Link to comment Share on other sites More sharing options...
jbc3 Posted June 27, 2006 Share Posted June 27, 2006 Run a 3900ohm resistor between the blue KS wire and ground and try a test datamaster recording. There should be no retard, since the resistor simulates the KS with no knock. Here is the link to Mike Chaney's knock desensitizer mod. Check your wiring... http://www.charm.net/~mchaney/knock.gif Jody Quote Link to comment Share on other sites More sharing options...
Bartman Posted June 28, 2006 Author Share Posted June 28, 2006 Run a 3900ohm resistor between the blue KS wire and ground and try a test datamaster recording. There should be no retard' date=' since the resistor simulates the KS with no knock. Here is the link to Mike Chaney's knock desensitizer mod. Check your wiring... http://www.charm.net/~mchaney/knock.gif Jody thanks Jody! By running the 3900ohm resistor the way you described (and the mod described by Mike Chaney) I shouldn't get an error code. Is that crorect? Quote Link to comment Share on other sites More sharing options...
that240guy Posted June 28, 2006 Share Posted June 28, 2006 I wouldn't touch the wiring to the knock module. Also leave the stock module in place. When you get the car tuned, the knock module can be desensitized with the programming. Quote Link to comment Share on other sites More sharing options...
jbc3 Posted June 28, 2006 Share Posted June 28, 2006 Yes, the 3900 ohm resistor to ground should eliminate the code. If it does, it means either the KS is bad or the desensitizing circuit is wired wrong. Quote Link to comment Share on other sites More sharing options...
wheelman Posted June 28, 2006 Share Posted June 28, 2006 Bartman, I made the Mike Chaney mod to the KS circuit and it works great. Before the mod I would see several thousand added to the knock count everytime I really got on it, but since it has been rock solid and I don't hear any pinging. I don't remember which value resistor I used but I measured the overall resistance of the circuit and then adjusted accordingly. That240guy, I've heard it's possible to desensitize the KS with programming but I've been through all the available parameters in TunerCat and haven't found one that does it. If you know which variable(s) to adjust and how then please let us know. Wheelman Quote Link to comment Share on other sites More sharing options...
that240guy Posted June 29, 2006 Share Posted June 29, 2006 i'll go into tuner cat this weekend and look at it. I don't remember off hand. Quote Link to comment Share on other sites More sharing options...
gvincent Posted April 25, 2008 Share Posted April 25, 2008 Old thread, Yeah I know but here goes. I might be having a similar problem, I mounted the knock sensor on the JTR plate because of clearance issues. The link for the Mike Chaney mod is no longer good, anybody have a copy of this mod? I haven't purchased a LT4 module yet but will if I have to. I have other issues also and have to get the new fuel pump installed before I get back to this problem and others. Some day I will actually drive this thing on the road! Oh those desensitizing variables tables in Tuner Cat...Where?? Thanks, Greg Quote Link to comment Share on other sites More sharing options...
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