Hi Guys,

I've just done a dohc headswap on my little 4G15. I have previously installed an emange too, for future use. All was working perfectly before the headswap (including the emanage).

Its come time to do the timing, so I shorted the timing ajustment plug to ground (located on the firewall), as described in the workshop manual. Ajusted timing to about 3 degrees BTDC. Turned off car, removed wire. restarted and checked timing.... about all the timing marks by about 10mm (about 20 degrees BTDC).

If I tap the accelerator briefly, it throws out timing further.

I've check the emanage, its not doing any timing ajustments, ive check the water temp sensor, it seams to be working ok.....

needless to say, i have concerns about running the engine with this problem.

Help please.

i don t quite understand your explanation:
you have swapped your cilinder head with a dohc one? what kind of emanage did you install? what engine code do you have, cos from my infos, the 4g15 has never been installed with a dohc head.

I ended up finding the problem. The coil + ignitor in the distributor was buggered. So I installed an upgraded external MSD ignition and coil. Which was causing the misfiring.

The throttle stop screw was also out of ajustment which was keeping the butterfly opening, causing a high idle and advancing the timing.

grassu075, In japan the base 5G Mirage Asti Z comes with a 4G15 DOHC. I sourced the head from one of those and installed that.

Heres a pic of the dohc.
(IMG:http://i29.photobucket.com/albums/c254/cnidus/Phot-0061A.jpg)