Setting base timing on RB25DET

[benl1981]

Just a quick one. Does anyone know if you have to short anything while you check or adjust the timing. On other cars I've had to short the diagnostic terminal. It's meant to be 10 deg BTDC right?

Cheers

[RB30-POWER]

You have to disconnect the TPS sensor on the RB25DET to stop the feedback.

The timing will jump all over the place even on idle if you don't disconnect it.

As per the manual.

[benl1981]

Thanks mate. Can you do this before or after you start the car. I see 15 deg is the standard.

I'm not really sure which wire I need to put the timing light pulse detector bit on.

I have the manual and had a look. It said somewherenear the plug on te top of the engine..I read a few posts and I think they said that one should be 30 deg. I'll have to try it.

Cheers

[RB30-POWER]

When you set the timing make sure its up to full operating temp.

Disconnect the TPS with the car off, just to be safe.

Make sure the idle is @ approx 650rpm to set the timing.

Timing should be at 15deg btdc (middle mark)

Don't advance it to much over the factory, its already tuned for high octane jap fuel.

At the back of the head there is a white wire in a loop, just near the coil pack plastic connector. This is the wire to use for the timing light.

I've typically found that with alot of timing guns, this wire, allows the light to pick up all pulses, therfore not giving a light as it should from cylinder 1.

I usually have to use an old ignition lead between the coil and the spark plug to attach the timing light too.

[benl1981]

Hey there - thanks for the reply. I don't really understand what you mean about an old lead between coil and spark plug. Do you have to pull the centre cover off to do this. All cars I've done this on have haed a distibutor i.e. no indiidual coil packs.

Thanks

[RB30-POWER]

Yeah connect your timing light clamp around the loop wire first and see it work succesfully.

If it doesn't work with your timing light, the only way you will get it to work, is remove the plastic coil cover (in between the cam covers), remove coil on cylinder one and use a normal spark plug lead (like on a dizzy car) to connect from the spark plug to the coil.

All this lead does is allow you to hook your timing light clamp around it, so it gets the correct signal to fire the timing light.

Hope that make sense?

It will make sense when you realise that stupid loop at the rear of the head doesn't work properly

[benl1981]

Thanks a heap mate. So does the fitting on the coil have a similar fitting like it would coming off a distributor . I would have thought there would be an electical lead to the coil and the coil sits on the spark plut so the fitting on the bottom of the coil will only suit sitting on top of a sparky. Or is there a short lead from coil to sparky. I'll open the workshop manual maybe I'll understand better then instead of bugging you guys.

Thanks

[RB30-POWER]

Not really, i had to modify a lead to suit the application really, but now i have it, i can rip the coil off and use the lead to get my timing light working anytime i have too.

You will suss it all out im sure. With a bit of luck your light will work connected to the factory loop, but if it doesn't you know where to head.

Catchya...