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Old 11-27-08, 05:08 PM   #76
KC95SC400
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hey KC can i reach undermy car and kinda feel for it? or does it need to be jack up? i have an auto sc300 93.. and i really want to try it. let me know plz
Doesn't apply to an SC300. Your transmission doesn't have the no 4 solenoid.

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Supercharged 96 Lexus SC400. Water / meth injection. Ross pistons. The "thick" factory rods.Gasket matched intake and heads. ARP head studs. Cometic head gaskets. ACL rod bearings. Flipped intake. Supra LSD. Built transmission. PI converter. Supra Tokico shocks with swift lowering springs. IMF headers. X-pipe. 2.5 inch exhaust. Adaptronic. Suprastick. Much more.

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Old 11-27-08, 05:08 PM   #77
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i didnt know which one to unplug, and i didnt really think i even saw the right one.
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Old 11-27-08, 05:09 PM   #78
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oh.. well that solves that hahaha
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Old 12-01-08, 02:08 PM   #79
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ok on my 96 OBDII sc4 i had the sensor unplugged like i stated....with it unplugged the car would sometimes shift about about 5200...so i decided to plug it back in and now it shifts at redline all the time...so my next step is to try cutting the wire at the ecu.....i will keep u guys updated
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Old 12-11-08, 05:28 PM   #80
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ok i cut the wire on my ecu but the cel came on as soon as i started the car.....with the sensor unplugged the the cel wouldnt come on till i drive the car about a mile.....so idk if its the right wire i looked at the diagram in post #53.....is it the same for obdII cars? can someone lmk if its the same wire to cut on an OBDII as on OBDI?
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Old 12-11-08, 06:14 PM   #81
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ok i cut the wire on my ecu but the cel came on as soon as i started the car.....with the sensor unplugged the the cel wouldnt come on till i drive the car about a mile.....so idk if its the right wire i looked at the diagram in post #53.....is it the same for obdII cars? can someone lmk if its the same wire to cut on an OBDII as on OBDI?
I think I had mentioned somewhere that I would be surprised if the CEL didn't come on for an OBD2 car. I THINK the wiring is the same but I'd have to double check it.

I'd have to look into it but I bet the ECU could be tricked with the proper resistor.

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Old 12-11-08, 06:18 PM   #82
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I think I had mentioned somewhere that I would be surprised if the CEL didn't come on for an OBD2 car. I THINK the wiring is the same but I'd have to double check it.

I'd have to look into it but I bet the ECU could be tricked with the proper resistor.

KC
yea im gonna cut the wire again an get the code checked and see wat it is....but if u can look into it for me that would be nice....

thanks
David
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Old 12-14-08, 07:13 PM   #83
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yea im gonna cut the wire again an get the code checked and see wat it is....but if u can look into it for me that would be nice....

thanks
David
Yes, I will. PM me tomorrow to remind me if you can.

KC
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Old 12-22-08, 12:15 AM   #84
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I unplugged that sensor tonight and went out for a test drive. First reaction: Holy Crap! you can REALLY feel the difference. Ive never been able to peel out from a stop, but tonight was the night. The tires spun like crazy.

The upside: when you step on the gas, you feel the power, the car literally pushes you back into the seat. I love it.

The downside: from 1st to 2nd gear, it shifts at 4500rpm. From 2nd to 3rd, it shifts at 5100rpm. I haven't tried from 3rd to 4th. This can get kind of annoying, but you can override it by putting it into low gear or 2nd. One more thing is, since my car is a 1996 OBDII, I got a check engine light.

Thanks a lot KC95SC400 for this find, and if you find a way to trick the ECU, let me know.
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Old 12-22-08, 09:22 PM   #85
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I unplugged that sensor tonight and went out for a test drive. First reaction: Holy Crap! you can REALLY feel the difference. Ive never been able to peel out from a stop, but tonight was the night. The tires spun like crazy.

The upside: when you step on the gas, you feel the power, the car literally pushes you back into the seat. I love it.

The downside: from 1st to 2nd gear, it shifts at 4500rpm. From 2nd to 3rd, it shifts at 5100rpm. I haven't tried from 3rd to 4th. This can get kind of annoying, but you can override it by putting it into low gear or 2nd. One more thing is, since my car is a 1996 OBDII, I got a check engine light.

Thanks a lot KC95SC400 for this find, and if you find a way to trick the ECU, let me know.
Cool, mostly. I'm still confused why it would be shifting early. Mine definately did not do that with the sensor unplugged. Could be something different with the OBD2 logic I suppose.

I think OneSickSC has moved onto the solenoid. I suggested that he try a 4-5ohm resistor in the solenoid circuit to see if the CEL stays off. If I were you, I'd wait until he reports on his.

KC
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Old 12-23-08, 04:45 PM   #86
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KC,

I'm gonna be doing the resister this weekend...so i will let you know.....SC-DRIVER i had mine unplugged and had the same thing happen would shift at like 5k all the time....plugged it back in an now the car shifts at redline.....when i try that resister trick i will def keep u guys updated.


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Old 12-23-08, 08:16 PM   #87
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Went out for another test run, from 1st to second it will always shift at 4500rpm, from 2nd to 3rd it will shift around ~5100rpm, and from 3rd to 4th it shifts at ~5500rpm. The shift point progressively gets higher.

Edit: I went for one more test run today, and the car WILL shift at redline when its not fully warmed up. When the temp needle stops moving up, that's when it shifts sooner. Very strange.

Last edited by sc-driver; 12-24-08 at 03:51 PM.. Reason: new information
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Old 01-02-09, 11:41 AM   #88
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went to radioshack got a 4.7ohm resistor and engine light still coming on......or does it have to be either 5 or 6 ohm resistor?
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Old 01-03-09, 03:12 AM   #89
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I have been reviewing the .pdf file KC uploaded in post #21, it seems that tricking the ECU with a simple resistor will not be possible. The ECU is reading the time it takes for each completed period. (The number of voltage spikes per millisecond) A resistor in series or parallel form will not affect this period at all. The signal still gets through with the same period.

In order to have the same "effect" as disconnecting the speed sensor while not throwing a CEL you would have to be able to minimize and decrease to voltage spikes while driving. This should also fix the early shift points. I was thinking maybe somehow being able to make it read as if it were at idle all the time.
Or like I said earlier, maybe adjusting the TPS sensor can make up for it, but the long term effects may be bad. I cant seem to try it because those screws are stripped very badly.
http://www.clublexus.com/forums/perf...-shifting.html
OneSickSC try adjusting that to see if it makes a difference. It wont make the CEL go away but it may help the shift points.
I believe solving this may be a good way to get those OBDII SC's to enjoy their low end power.

Yet it still confuses me how the car is able to shift at red line when the car is still cold.

David
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Old 01-03-09, 01:26 PM   #90
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alright i did one test run with the wire cut at the ecu(cel on) wit the car at normal operating temp....car shifted fine at redline.....but with the sensor unplugged it shifted at 5k as i stated above......so i think for us OBDII guys we might have to just cut the wire and deal with the cel on unless some can figure out how to trick the ecu.....

David
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Old 01-03-09, 01:26 PM
 
 
 
 
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1995, 94, a340e, a342e, automatic, downshift, es300, flashing, lexus, light, od, p0715, ranger, sensor, speed, toyota, transmission

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