gp90se Posted September 12, 2005 Report Share Posted September 12, 2005 Just things that ive been looking at, but could an LT4 knock sensor work as an upgrade from the stock 3.1? IIRC, they look the same and the LT4 is supposed 2 be more responsive then an LT1 (which is close 2 what the 3.1 has) Quote Link to comment Share on other sites More sharing options...
SleeperRed90TGp Posted September 14, 2005 Report Share Posted September 14, 2005 I would guess that all GM KS are created equal. I would also guess that if one or the other does a better job its in the computer or in our case the EPROM. Jud Quote Link to comment Share on other sites More sharing options...
TurboGTU Posted September 14, 2005 Report Share Posted September 14, 2005 Our knock sensors are based on bore size. So if your looking for a Upgrade..there isn't any. Only new replacement. The 3100 would be the only one with the same bore size..but it in a different location..might be different audio harmanics there. Quote Link to comment Share on other sites More sharing options...
Jeff M Posted September 14, 2005 Report Share Posted September 14, 2005 Our knock sensors are based on bore size. So if your looking for a Upgrade..there isn't any. Only new replacement. The 3100 would be the only one with the same bore size..but it in a different location..might be different audio harmanics there. TurboGTU speaking the facts and nothing but the facts 8) Each style of knock sensor is for a specific sound range of a particular engine, no swapping allowed! Also no "upgrade" as the MEMCAL is set to read the knock signal from the sensor and then the chip to do the work at retarding the timing as needed. Blue ones are for bigger engines and black ones for us small blocks There are other stand-alone knock systems like the LT1 and LS1 but ours is built into the circuits of the MEMCAL, works good btw. Jeff M Quote Link to comment Share on other sites More sharing options...
TurboGTU Posted September 16, 2005 Report Share Posted September 16, 2005 Im glad our knock sensors are on the block..unlike my ford turbo cupe..which is located on the intake manafold. :? . If I have anti-pump up lifters or a mechanical cam..things get out of hand with retard. Even stock wise..I have to disconnect it during track time or on the highway. My stock knock sensing works good. Has kept my piston out of having a new sunroof . Quote Link to comment Share on other sites More sharing options...
RareGMFan Posted September 16, 2005 Report Share Posted September 16, 2005 If the knock sensor is disconnected on the 3.1, will the computer resort to default like the rest of the sensors? And how sensative are these things? I have a code for ESC right now (along with TPS low, and MAP high, just like the TSTE). I changed out the TPS with a brand new one, and that brought the idle down nicely. The thing actually ran really good when I first got it back from having the fuel pump changed. Then, about a month ago, it started getting hard to start when it's cooled down (starts on a dime if it's been driven). The last couple of weeks, if I push the pedal to half throttle, the engine will start vibrating almost exactly like the 160 chip fuel cut off, and won't accelerate any harder. The SES doesn't go away anymore, either. I have a suspicion the KS is cutting back timing dramitically. I had someone briefly scan it, and he said it's definitely sending a signal for knock almost consistantly. I already bought a new one. Going to try swapping it out this weekend. The only thing worrying me is.......if it's actually the sensor (or other related, non internal issues), or if the engine actually IS knocking. I can very faintly hear some knock. No worse then a good portion of the older GMs I've heard. I've heard, and owned cars with louder knock then this, and non of them have triggered the ESC code (or anything else, for that matter). But being the paranoid freak I am, I usually expect the worst. So far, the car has a new fuel pump, new fuel sending unit, new fuel filter, and cleaned fuel tank and injectors. Nothing has been done on the electrical end, yet (though I have the parts ready, and waiting). I was just afraid to go on any further with this car until I can confirm it's not an actual knock. Don't want to blow money on a car that's going to need an engine rebuild/serious internal work. I don't have the time for such a project right now, and would have to get rid of the TGP if this was the case. Quote Link to comment Share on other sites More sharing options...
Garrett Powered Posted September 17, 2005 Report Share Posted September 17, 2005 knock isn't something you can hear I think. Your sensor barely hears it before it makes an adjustment. unless it is a rod knocking (bad bearing) or lifter being noisy, like mine . I don't know what you mean, I just think they are different sounds. What the knock senses is pinging right? I got mine and haven't gotten around to it yet either. you might want to heat it up (the block)with a torch for a few minutes before attempting to remove it. I have heard of the tip breaking off in there. Thats what I learned when I did Ford head bolts they break off all the time. we heated the metal around the bolt with a propane torch and they came out with locking pliers. Quote Link to comment Share on other sites More sharing options...
TurboGTU Posted September 17, 2005 Report Share Posted September 17, 2005 Plenty of knock at rpm can be alot of things. If its fuel..you'll know by the plugs condition...are they black..or are they blistering white with peper red frecles? It can also be a stuck open EGR...letting alot of exhaust gas go in at high temps. It can be the usual piston slap asociated with higher mile engines. Not something to get your panies in a bunch about. Forged pistons would have even worse piston slap. It can also be a mis ajusted/stuck starter gear hitting the flywheel. It can be a vacume leak you must have overlooked. Pressure testing the port for the Map and fuel pressure regulator is easy since your never suppose to have leaks there..just use a vacume pump and see if it holds vacume. You can almost certinly find a vacume leak with a arosol can of starter fluid or carb cleaner spraying around the hoses and away from the air filter while the engine is on..a spike in rpm will indicate a leak. Having a ALDL scanner is a must for any EFI car you own. YOu can see all your sensor readings and knock sensor couts and time retard..well many things. This way you won't chase your tail going to parts store and never seeing results. Quote Link to comment Share on other sites More sharing options...
Garrett Powered Posted September 17, 2005 Report Share Posted September 17, 2005 shopping list. :read: ALDL scanner, carb cleaner for possibly stuck EGR. I put in 1 thin shim just to be sure my new gear reduction starter has clearance. Quote Link to comment Share on other sites More sharing options...
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