1jz jzx90-mx83 misfire

[Tyler_846]

hey guys, iv got a 92 mx83 cressida and iv put a jzx90 1jz into it. when i drive it just as it gets onto boost it misfires, coughs and splutters until you change it up a gear then it does the same.. could it possibly be running in limp mode ? if so how do i go about getting around it ?
cheers

[Tyler_846]

Iv been told I have to ground my STA wire, is that correct? And do I do that via a relay? If so which wires will I be needing to use? Cheers

[woz]

Firstly get new plugs and gap them to 0.8mm and check your coilpacks for cracks.

[dumbass]

if it has a rev limit aorund 2500 or 4000 rpm it could be wired incorrectly
have u hooked up the check engine light and tried to get codes from it

[cresslux]

it sounds like you have bridged the nsw and sta wires
if its auto, you need to hook up the neutral switch using a relay, as mx83's and jzx90's use a different method of isolating the starter.
if its manual, just hook the sta wire to your starter motor trigger wire, and leave the nsw wire. (you can do this with an auto as well, but it will start in any gear)
and i agree with dumbass, check for codes.

the nsw and sta wires are in the main power connector on the engine harness (same plug that has the injector power and starter wires) the sta is a thin black wire, and the nsw is a thin black wire with a white stripe.