How do you adjust the timing on a 3000GT?

Answer 1

THEE ANSWERthe dohc engine uses coil packs compaired to the distribiter used in the sohc. to adjusst the timing on the dohc, it can be done by using a resistor in place of the IAT sensor (10K Ohm i think). this tells the ecu that the air intake tempture is lower than it really is so it thinks that the engine is cooler than it really is allow a more advance timing and injector pulse curve. resulting in more power less gag mileage. BUT advancing the timing can cause spark knock , detonation, (same thing) which could destroy your engine. so look up what a datalogger is and that will let you moniter the knock ect. hope this helps

****EDIT****

He is asking how to adjust timing, not advance timing w/ a resistor. Resistors will decrease the hz the ECU sees to lean out/advance timing is cheap performance mod and should be avoided at all costs. You can find these all over Ebay, and if you buy one of these or install anything other than a piggyback/standalone to reduce your airflow to the ECU, you deserve the blown engine when it happens. They tune the ECU for a safe air fuel ratio from the factory, no need to lean it out to the borderline of knock/engine failure. If you do, at the very least do yourself & engine a favor and get a datalogger to monitor knock, and a wideband 02 sensor to see what your AFR actually is.

TO ADJUST IGNITION TIMING (valve timing is a different animal)

1.) locate the tan/brown plug between passenger strut tower & firewall (near where all the engine wiring comes through the wall)

2.) take the cap off, jump a wire from that terminal to the frame of the car. This puts the ECU into a fixed mode, so it will not automatically adjust ignition timing.

3.) hook up a timing light to #1 plug wire (can do loan a tool from autozone/advance auto)

4.) start car and point light down to crankshaft harmonic balancer (pulley).

5.) You will see the notch on the pulley, make sure it is at 5 degrees BTDC, + or - 2.

6.) If not, rotate the sensor until it is, then lock it down. Turn off the car, remove the jumped wire, then restart the car. The timing should now automatically adjust to about 15 degrees.

7.) If the car doesn't start, you may need to rotate the CAS arm 180 degrees, then re-install.