Timing 180 degrees out

Hi there,

I just recently got my project car engine finally running the other day. It took a little while to get her to fire though. Its a 1jz vvti that i have build with forged pistons and rods, aftermarket cams, lots of other goodies and my best wiring harness to date. It took 2 days to get her to actually fire. Using what i thought were the right trigger settings of 36 -2 +3, 65 degree angle and a tooth offset of 9. My timing light confirmed the timing at 0, 10, and 20 degrees but it would backfire through the manifold. Changing the tooth offset to 40something (i cant remember the exact number) made the engine that had been sitting in my garage fire up for the first time. After i shed some tears of relief and joy, i started to wonder why i had to do what i had to do. Its still a little gray in my mind. Essentially i know the timing is 180 degrees (even 360 degrees) out but this didnt happen with my old set up with the same ecu on the same engine before the rebuild. My original map when the engine was unopened run a tooth offset of 9.

Thank you in advance

Not really knowing anything about the 1JZ if the engine and ECU setup is the same as before the rebuild it sounds like the cam timing is 180 degrees out, meaning TDC No 1 isn't on the compression stroke but rather the exhaust stroke. The only thing that could cause this, if everything else is the exact same as before, is the cam timing.

Thank you for your reply. I just popped the timing light on again and ive had to lock the timing to -20 to get it at zero on balancer

Use the rear camshaft position sensor for reference

What ecu are you using?

Does it cycle any trigger errors or does it have a scope so you can scope the trigger pattern?

I would usually say cam timing although this should be pretty noticeable when the engine is running.

Other things could be sensor polarity or having the intake and exhaust cam triggers around the wrong way.

Thank you for the replies. Ihave sorted the issue now. All i had to do was change the tooth offset.car runs brilliantly. Thanks for the comments :)

the 1JZ VVTi runs a wasted spark setup so getting it running 180 degrees (360 Crank) out is a common mistake on initial setup

Thank you for your reply. I am running 2jz cop coilpacks i have fitted to the 1jz vvti. I have learnt hahaha thanks. Engine runs fantastic