1.5jz tps signal issues

limitedgt4

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#1
Hey guys ive searched the web quite a bit and cant seem to find the right search words to find my issue and thus am here.

Background:
Car had a 1jz with 2jz jdm aristo ecu and harness to match and was lightly tuned on an apexi neo. The car worked fine until it showed signs of a BHG. Deided to go with a 2jz bottom end and Sent car to a mechanic friend of mine to get the 1.5jz into my 88 mk3. We decided to change the harness while we were at it ( got the harness from tweak) now after putting it all together, we plugged te neo and it is showing a tps signal of 100% even when the engine isnt running but the key is in the on position. Turn the car on and still the same. I tried a different tps from a 2jz and still the neo is reading 100 on the tps signal. Additionally the car stalls and seems to not want to rev when i press the gas pedal hard. The car does idle at around 600 rpms which also seems a little low based on what i have seen. Previouly it idled around 900hp.
 

rhs

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#2
I think it's common for 1JZs to idle low sometimes due to the IAC sticking. Mine does that.

Is it possible you have the cruise control and TPS plugs switched? I seem to remember them being similar, but maybe that's not possible.
 

limitedgt4

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#3
Ill look but i dont have cruise control and i dont believe the harnes tweak made for me has the cruise control.... i feel the wires on the tps plug are switched but i cant find any frame of reference for me to compare. I know how to test the tps and i have tested 2 of them and i still get the 100% throttle signal in the apexi neo when the car is off and even when its on just runing on idle
 

limitedgt4

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#5
Any suggestions on what the voltage output should be on the plug? I bought a new multimeter to test it but i dont know what the right outputs are to know if a wire is backwards
 
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rhs

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#6
Try calling Tweak'd. They should be able to help troubleshoot it since they made the harness.
 

limitedgt4

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#7
Check wiring from sensor plug to ecu plug for continuity and it checks out. Doesnt seem to be the wires... anyone know of issues with the apexi neo?
 

RacerXJ220

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#8
Tweaks harnesses need to be checked by the end user. Every wire. He forgot to add the ground wires on my harness. Forgot, as in they did not exist in my harness from him.

Additionally, he had my TPS wires backwards.

He has costed users hundreds of dollars outside his "services" on many other cars. It is ridiculous. Took me three days of back and forth bullcrap calls and emails, until I finally fixed his harness myself.

Always double check wiring from that guy, before you even put it in the car.

I built my own harnesses after that one.
 

Satan

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#9
Like said earlier... verify the TPS wiring to the ECU (tone it out) to make sure that they are not backwards (which is equal to the 100% open).
 

limitedgt4

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#10
Thats what i figured could happen but i believe i tested it and it was good. Ill double check. I even did a continuity test from the tps plug to the ecu plug to make sure the wires ended where they were supposed to. Ill do it again as i think i may have confused the 2 middle wires