Hi guys, I’ve picked up a nightmare IS300 project with an EMU black and the P&P harness and have been tracking down a lot of little issues since I got it. Unfortunately this latest one has me a bit stumped and I’m hoping for a bit of help.
First off here’s a video of the sound:
To me it sounds like ignition knock more than rod knock, and essentially disappears above about 1500rpm. Once the rpm hits around 800 the knocking gets significantly louder and rpm drops to around 550-650. Behavior also leads me to believe it’s ignition knock and not rod knock but maybe I’m wrong and this quickly becomes a parts car.
So far I’ve checked ignition timing with a timing light and it was set correctly, I rotated the engine and checked mechanical timing and the crank and both cams line up with their respective marks at 0 degrees. Spark plugs are new, I replaced the chinese LQ9 coils with GM coils. The previous owner wired in their own rat’s nest injector and ignition wiring so I made a new injector and ignition harness and wired it directly into the EMU black. I tested and confirmed all outputs worked and were firing according to what they were numbered.
The car is an 2002 automatic Lexus IS300, 2JZ-GE VVTi with a GTE headgasket to reduce compression, EMU Black with the P&P harness (injectors and ignition depinned), custom injector and ignition harness, cheap chinese turbo kit, front mount intake, manual throttle body, ID1050X injectors, knockoff walbro pump, rewired fuel pump to 12v relay bypassing stock variable voltage.
The ECU is using the latest 2.175 firmware and I’m using the base tune from the ecumaster website for the plug and play harness. The only changes I’ve made are setting the injectors to the preset 1050X injectors in the wizard, changing the firing order under ignition outputs to reflect individual coils instead of stock wasted spark wiring (1,5,3,6,2,4), and reducing dwell time to 3.5-2ms.