Code 52.... WTF, Replace Everything

bigaaron

bigaaron

Supramania Contributor
Apr 12, 2005
4,692
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50
Pomona, CA
www.driftmotion.com
My knock code only came up once in a while, at high rpm. It didn't seem to have any affect on the engine though. I had removed the knock sensors to inspect them for cracks in the plastic connector, and they looked ok, but I just threw in another pair from a known good engine. Then the harness was replaced when I went with the maft pro because it had other damaged areas on the old harness. Then the knock sensor code still came up once in a while, so I tried another ecu....actually a few different ecu's. So at that point, even though swapping out parts may not be the most efficent way of troubleshooting, what was causing it? At some point I did get out the o-scope and both sensors looked to have the same type of voltage and waveform.
 
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suprahooked

Built 7M
Jun 20, 2006
1,160
0
36
pa
jetjock said:
Jeesh, I hope he's got them in the right spots. If not that could screw up the gating time, the period when the ECU looks at them to confirm they're connected. You may have stumbled onto something here.
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Yes it sounds like he dont have the front sensor in the right spot, Because there is no hole in front of the sensor if you go back and look at the pic i posted. John
 
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dbsupra90

toonar
Apr 1, 2005
2,374
0
0
indiucky
jetjock said:
Jeesh, I hope he's got them in the right spots. If not that could screw up the gating time, the period when the ECU looks at them to confirm they're connected. You may have stumbled onto something here.
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its worth a shot, but i dont think it to be the case. friend of mine didnt know any different and had them mounted in the center and rear hole. its been like that for 2yrs and never a code 52. i just recently spotted it being in the wrong place when pulling his intake manifold.
 
jetjock

jetjock

creepy-ass cracka
Jul 11, 2005
9,439
0
0
Redacted per Title 18 USC Section 798
Knowing this community I figured someone out there had put one in the wrong hole. The proper places are cylinders 2 and 5. I'm not sure if them being companions figures into it or it's because the sensors need to be spread over the block. Knowing how the system samples for knock I suspect it's the latter.

Many knock sensors (GM comes to mind) use an integral resistor tied to ground. The value is high enough to prevent attenuation of the sensor signal but low enough some current can be trickled so that the ecu can determine when they're disconnected. Toyota doesn't do it that way ie; if you ohm a good 7m sensor you'll find it to be open. Instead the TCCS listens to every ignition event. The gate period is the time that happens. Anything outside it is ignored.
 
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supraguy31

New Member
May 10, 2005
626
0
0
Pembroke, NC
I wish you guys would just post up everything that you know about these cars. I would sit here and read all day and learn through every Post. Well, Its been confirmed that it was in the incorrect Spot. I would have never Imagined that there would be a Extra Hole in the Turbo Motors. I have a Non turbo block here and It has the 2 turbo Hole fulled in. Im wondering why the Turbo Motors didnt do the same for the Non turbo Spot.

Im going to go and start it up and see what it does. Crossing my Fingers that its solves the Problem. As for the other Wiring Harness that was Pulled out of the car, The connector wouldnt fit snug on the Sensor as it seens that the locking Clip was either warn down or the Tip on the NS was worn down + the wire has been snipped and twist tied back together.

You learn more and more everyday as I do with you all.

BRB
 
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suprahooked

Built 7M
Jun 20, 2006
1,160
0
36
pa
supraguy31 said:
I wish you guys would just post up everything that you know about these cars. I would sit here and read all day and learn through every Post. Well, Its been confirmed that it was in the incorrect Spot. I would have never Imagined that there would be a Extra Hole in the Turbo Motors. I have a Non turbo block here and It has the 2 turbo Hole fulled in. Im wondering why the Turbo Motors didnt do the same for the Non turbo Spot.

Im going to go and start it up and see what it does. Crossing my Fingers that its solves the Problem. As for the other Wiring Harness that was Pulled out of the car, The connector wouldnt fit snug on the Sensor as it seens that the locking Clip was either warn down or the Tip on the NS was worn down + the wire has been snipped and twist tied back together.

You learn more and more everyday as I do with you all.

BRB
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Good Luck:icon_razz
 
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supraguy31

New Member
May 10, 2005
626
0
0
Pembroke, NC
Well, Went out and started the car up. Rev it up to 3000 RPMs and I still got the Code. I thought about it for a minute and went into the Garage and Pulled from my Stash 2 Knock sensors that I know came out of a turbo Engine. Install both the sensors and made sure I had a good connection on each Sensor, Did a Quick check to ensure that there wasnt any codes in the system before I started the engine, Let it sit Idle for about 20 Seconds and then I rev the motor up to 4000 rpms a few times and then Held it at 4000 for about 10 Seconds and no Code 52. I can say for sure now that there is a Difference between turbo Knock Sensors and Non turbo Sensors.

Thank you all for all your Imput on this as I would have not been able to figure it out and Probably would not be able to sell the car anytime soon. All I need now is a AFM sensor and I should be good. If or when Im in you alls area, Im going to look you all up and buy you all a Beer or Beverage of your Choice. I try and help the Community out as much as Possible. Its just nice to know what when I have a Problem I can turn to the Professionals here. This is Probably the reason I dont go to Supraforums for anything car related.

Robert
 
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suprahooked

Built 7M
Jun 20, 2006
1,160
0
36
pa
Thanks Robert :icon_bigg ,I am just a carpenter that likes to have a project to get away from the wife.:biglaugh: Glad you got it going.
By the way i like Miller high life.
 
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supraguy31

New Member
May 10, 2005
626
0
0
Pembroke, NC
Im originally from N.C. and Im retiring in 3 Years. Im never getting out of the Supra Business and Ive only been into the 82-86 7MGTE conversion for about 2 Years now. Ive done alot of these cars and there arent too many of them on the road these days running High 11s to Low 12s in the Quarter mile. Mine is one of them (the one in my Sig) Its my Pride and Joy just Im always trying to make it better. Looing for a turbo for it at this time. Something that spools full boost around mid 3000 and will pull hard all the way to redline. If I can find this then I will be set for a while as my 720cc Injectors are getting lonely and waiting to get to work.
 
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