Thread: Disco Tuning 3.9L

Should have good solid power range up to around 4000rpm. Have you checked your distributor timing is advancing with the revs? Might have a seized advance mechanism. Could also be a blocked exhaust.

If by 3.8 V6 you mean a Commodore then the Disco is never going to compare if you mean day to day driving.

What Utemad said, a Disco will never drive like a Commodore. A two plus tonne 4wd vs a 1600 kg road car?

check you vacuum advance, if the diaphram is split you could lose power.
Test by sucking on the hose to see if it hold vaccum

Thanks guys, yer i reset the timming to 10 degs BTDC , it's a little slower to start , with a bit better power, also cleaned the air flow meter and butterfly outer housing , I have already replaced the vac advance diapham, it appears to advance if you stab it with the timming light on, I have heard you can adjust the airflow meter from a specialist in melbourne , does anyone know how this is set correctly,
It has a little stutter when you 1st stab it but then comes good if you do it a couple of times, any ideas?

If you do a search on air flow meter or AFM you should find posts describing the adjustment procedure. Plenty of us here have done it.

Originally Posted by Bigfella 2010

Thanks guys, yer i reset the timming to 10 degs BTDC , it's a little slower to start , with a bit better power, also cleaned the air flow meter and butterfly outer housing , I have already replaced the vac advance diapham, it appears to advance if you stab it with the timming light on, I have heard you can adjust the airflow meter from a specialist in melbourne , does anyone know how this is set correctly,
It has a little stutter when you 1st stab it but then comes good if you do it a couple of times, any ideas?

Could be weak ignition, after you have adjusted the AFM look at plugs, leads, amp, coil in that order. See my post for ignition upgrades if you're game: Lucas ignition amplifier replacement by Bosch 024

hi ,

Check to see what the timing should be first. It should be on a plate on the drivers tapet cover or on the front of car.

Then i suggest to clean out the T-Piece joining the Tapppet covers to the Plenum chamber. Inside the small tube there ia a oriface that gets clogged up with carbon and effects the performance of the vehicle. Clean that out and give it a go.

Also is your car dual or single fuel.

Hopes that helps.


carla