mk3 1jz supra high boost signal at idle

[limitedgt4]

So i got a boost problem. As soon as i turn on the ignition, the dash boost gauge needle shoots up and when i press the gas i get fuel cut (or something similar to it), it goes to stall and then it picks up again (sometimes it dies). I unpluged the hose to the sensor and the needles still up. I tried another sensor i got and same thing. I have an apexi neo wired to the ecu (not sure if its related but worth mentioning).

Anyone one have any thoughts? I tried some googles but couldnt find much

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[Nick M]

Because you are using a different engine and harness, then I can't really comment about the 1JZ (ha ha) part. The sensor (common 3 wire) varies the resistance between the gauge and ground. In order for that to happen, you do not have resistance. Said another way, you have 12 volts at the signal wire.

On the 7MGTE which you say you do not have, that gauge has nothing to do with engine management.

 

[limitedgt4]

Thanks for the input, thats what i though that the signal wire was receiving voltage and thus spiking but that was not the case. Ive been at this project for 2 years and ive forgotten some of the small details of the swap. The reason it happened is because the boost pressure sensor was not connected. On a 1jz swap youl have both the boost pressure sensor (for the dash gauge) and the map sensor (for the ecu) i forgot both had to be plugged in so i only plugged the boost sensor and the dash went crazy

 

[hvyman]

That shouldnt happen. There both on different circuits.

the gauge sensor is ran through the body harness.