Been having problems with my car for awhile with engine knock. After reserching today for awhile, could it be a bad knock sensor? Heres the reason why I DONT think that that is the reason for the engine knock, its as simple as when I use HPTuners it shows the knock retard. When I unplug it, it just shows zero. Id think if it was malfunctioning that it would show zero even when plugged in. What are yalls thoughts?
3400 SWAP DONE. 187WHP 212TQ (14.2 @100MPH NA) 240WHP 310TQ (N2O)
A malfunctioning knock sensor can incorrectly detect spark knock even if it doesn't exist. So you could have an insane amount of knock and it not detect it, or you could have none and it be detecting tons of it.
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Mike
You're just havin too much fun with that v6.......... Is the engine actually knocking or is it just knocking on the datastream? I alreading threw a couple rod bearings on my 1st v6 it was ugly.
C:\Users\Phillip\Pictures
Its actually knocking. You can feel/hear it and see it on the data stream. What the data stream shows is this, when the knock occurs, the fuel trims go to max lean, it knocks and the injector duty cycle during this is kinda flat lining. When the knock goes away everything goes back to the way it should look, fuel trims full rich (only under WOT) knock goes away and injector duty cycle shoots up. You can actually FEEL the power coming back in hard core when it stops. Im really at a loss...
3400 SWAP DONE. 187WHP 212TQ (14.2 @100MPH NA) 240WHP 310TQ (N2O)
Sounds to me like there is a different issue here. What do the other inputs look like? Things like MAP and TPS?
Also. What year of engine do you have and what year of computer?
i find it amusing that SHOoff has nothing better to do but follow me around & be an unhelpful dick in even cross-forum. - Jon Mick
MAP and TPS are fine on HPT. Its a 2002 from a GAGT.
3400 SWAP DONE. 187WHP 212TQ (14.2 @100MPH NA) 240WHP 310TQ (N2O)
Are both the computer and the engine from the 02? Cuz I see your car is a 97, not sure if the N-body changed computers in 00+ like the J-body did or not.
i find it amusing that SHOoff has nothing better to do but follow me around & be an unhelpful dick in even cross-forum. - Jon Mick
I/m going to throw my two cents in. It sound to me like your knock sensors are working correctly and you are having trouble with one fuel injector. I would check the grounds from the injectors to the ECM. You may have a intermittent connection or 1 bad injector. I think the Junction is C101 on top of the intake manifold to the C2 and C1 plug. Check continuity when the motor is giving you Problems. I wrapped my harness in a ton of black tape and I had corroision on one of the soldered splices i made, giving me grief. The tape sealed in the water ,moiture giving me corroision, I since took apart the harness and wrapped it loosly it with tape and plastic. Good Luck let us know what you find.
I don't think it is the injectors because the problem was there with the stock injectors. I put trailblazer injectors in about 12 months ago and it still does it with them. I have been chasing this problem for a long time now. I have also check the injector wiring.
3400 SWAP DONE. 187WHP 212TQ (14.2 @100MPH NA) 240WHP 310TQ (N2O)
I recently ran a can of seafoam through the engine and it seems to have greatly helped this problem. Carbon on the intake valves im thinking? Possibly soaking up the fuel causing it to knock?
3400 SWAP DONE. 187WHP 212TQ (14.2 @100MPH NA) 240WHP 310TQ (N2O)
I don't know how much could do it, but carbon inside the combustion chamber even could increase the compression too. I've heard of that happening when an engine is really old. But I wouldn't think it would build compression that high.
Give it a while see how it runs.
i find it amusing that SHOoff has nothing better to do but follow me around & be an unhelpful dick in even cross-forum. - Jon Mick
Well I take back that its running better, I ran it tonight and it was still doing the same thing. I even put a new MAF in it to see if it was malfunctioning. It runs fine if you just roll into the throttle, but if you take off from a dead stop hard accel at WOT it goes lean in 1st, 2nd and 3rd. Im at a loss...
3400 SWAP DONE. 187WHP 212TQ (14.2 @100MPH NA) 240WHP 310TQ (N2O)
are you sure the tps is good? i would scope it to make sure there are no opens. when at i think 75 or 80% throttle, it should richen up quite a bit. when at wot it ignores the o2 and just goes off of crank/cam, map/maf, iat, and tps for fuel control i thought. may be missing something.
lol, would be funny if it was something with trac. control.
what does your injecotor duty cycle look like when it goes lean? If the idc drops when it goes lean it means your tune is mess up and you need to retune, or you have a serious internal issue with your pcm.
1994 Saturn SL2 Home Coming Edition: backup car
2002 Chevy Cavalier LS Sport Coupe: In a Junk Yard
1995 Mazda Miata R-package Class=STR
Sponsored by:
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WPI Class of '12 Mechanical Engineering
WPI SAE Risk and Sustainability Management Officer
Do either of you have HPT first of all...
3400 SWAP DONE. 187WHP 212TQ (14.2 @100MPH NA) 240WHP 310TQ (N2O)
Nitrous Nate wrote:Do either of you have HPT first of all...
I do, tuning for boost on alpha-n is a bitch.
1994 Saturn SL2 Home Coming Edition: backup car
2002 Chevy Cavalier LS Sport Coupe: In a Junk Yard
1995 Mazda Miata R-package Class=STR
Sponsored by:
Kronos Performance
WPI Class of '12 Mechanical Engineering
WPI SAE Risk and Sustainability Management Officer
Leafy wrote:Nitrous Nate wrote:Do either of you have HPT first of all...
I do, tuning for boost on alpha-n is a bitch.
What boost? I see nitrous in his profile, but no turbo or supercharging.
If you can actually hear the knock as well as log it, I don't think it's the sensor. It really does sound like a tuning issue. It's lean, and because it's too lean at WOT, it knocks. Try tuning in more fuel at WOT and see what happens.
Just a random tidbit to legitimize the fact that I have HPT. He posted a new thread with screen caps from his log, the damn think makes no sense to me as to why it does what it does. I mean, no knock in first, @!#$ tons of knock in 2nd, and some knock in 3rd, just a random dip in the actual fueling of the car just before redline, but only in 1st.
1994 Saturn SL2 Home Coming Edition: backup car
2002 Chevy Cavalier LS Sport Coupe: In a Junk Yard
1995 Mazda Miata R-package Class=STR
Sponsored by:
Kronos Performance
WPI Class of '12 Mechanical Engineering
WPI SAE Risk and Sustainability Management Officer
I'm telling you, its the MAF not being tuned..... He sent me a PM saying that he was only tuning the VE... Unless he has the MAF failed (which I doubt), the tune is completely off......
P&P Tuning
420.5whp / 359.8wtq
Had this same tune on the car for about 3 years with no problems, just started acting up this year.
3400 SWAP DONE. 187WHP 212TQ (14.2 @100MPH NA) 240WHP 310TQ (N2O)
How far are you from a stock 3400 tune anyways? I can't believe it's been thrown off a whole ton.
i find it amusing that SHOoff has nothing better to do but follow me around & be an unhelpful dick in even cross-forum. - Jon Mick
Its not that far from it. I have changed a little at WOT in both the VE tables and the timing tables. Im going out to see Mike at Milzy next week.
3400 SWAP DONE. 187WHP 212TQ (14.2 @100MPH NA) 240WHP 310TQ (N2O)
Nitrous Nate wrote:Its not that far from it. I have changed a little at WOT in both the VE tables and the timing tables. Im going out to see Mike at Milzy next week.
Tell Milzy I said hi. We go back a few years.... Saw/talked to him at my buddy's shop in Dayton a few months back..... Tell him Ryan said he was wrong about the Mustang "knock"! He will probably shake his head and laugh......
P&P Tuning
420.5whp / 359.8wtq
Milzy tuned my 3400 and its flashed to a Monte Carlo I believe. 3uns perfect, even with Mikes stage 2 heads and cam package.
C:\Users\Phillip\Pictures
