1JZ tach and idle question

tErbo b00st

Hard Ass
Mar 20, 2007
185
0
0
39
Iowa City, IA
www.kougakuracing.com
I bought my 1J swapped mkiii (NA model) a couple years ago. I redid the wiring last winter as the person who did the swap had a rats nest (he did it real quick and was gonna fix it later). I drove it all summer fine, but there are two issues that I can't resolve

1. The tach does not work anymore. It use to work fine but somewhere in my rewire it stopped working. I have tried hooking up a couple different wires (ign1 and ign6) to what I think is the tach signal wire near the glove compartment (pink wire iirc). I can't get it to move at all? Is there something I could have easily done? Maybe a ground? Any suggestions will help, and I'll try anything.

2. My idle control is gone. I had to turn the throttle body stop screw to hold an idle. It works, but it's tough to start when cold. I have checked my temp wiring, and iacv wiring countless times. What does the IACV rely on? The weird thing is it worked when I first fired it up and a couple times after that. But than stopped working a couple days later.

Any input is appreciated. Thanks.
 
Last edited:

str8_6

master yuepeng
Mar 14, 2007
241
0
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wa
are you saying that its hard to start when cold or it'll start but wouldn't want to idle when cold?

i had the same issue of it starting always but would not want to idle and if it did, it'll idle at like 400rpm or sometimes barely.

the iscv i believe part of its signal is from the temperature sending unit to the ecu. the weird thing is, i took that apart and tested it exactly like tsrm and it worked fine, but i still had that issue.

i'm not sure about your tach issue though.