406oc.co.uk

I am planning to add some boost on the 1.9td 406,but a friend told me that I can't adjust the fuel bolt because the pump is semi automatic.I have a black box on the rear of the pump,not the bolt where can adjust the fuel bolt (like the videos on youtube for the 306).Is there other way how can I increase the fuel because with out this I can't gain power.

what fuel pump is it? (bosch, lucas...) i thought they only fitted electric ones to the 2.1td, im in the process of swapping mine for a mechanical one and doing the same thing

I've done a little research into this myself a few years back. the 406 1.9 does have semi electric fueling, the delivery is all mechanical but there is a small amount of the delivery timing controlled by the ECU.

The good news is that the black box is actualy just a cover for the stop solenoid wiring that just unclips.

The bad news is that under it is a metal plate covering the max fuel screw that i haven't really investigated into how to remove it, but intend to do so soon because i rather fancy some more midrange. I tuned a freinds 405 TD in conjunction with the autospeed articles and it transforms the car.

Part 5 of the autospeed articles:
http://autospeed.com/cms/A_109345/article.html

IIRC, the fuel screw is often fitted with an anti-tamper plate. So remove it and begin tampering ^^

The pump needs to come off to remove the injection pump immobiliser shielding. Its not an easy job and best left to a specialist. Tbh, with all the other adjustments made on the pump you dont need to touch the max fuelling screw unless your boost is much higher than standard. My old Xantia Td went very well, pulled up to a ton smoothly and kept on going to 115mph.... its a great engine!

thanks for all your help,
the diesel pump is bosch,with kkk turbo.

xantiaman how much boost do you give the engine?I read on other sites that 17 psi with standard intercooler will be fine.I fitted a boost gauge and it's 13psi which I think it's standard.Do I notice any difference without adjusting the diesel bolt (under the black box)?

Wisdom to be found here, here, here and here.

Hey check it out, the guy also has an XUD clutch change guide...

redfar wrote:thanks for all your help,
the diesel pump is bosch,with kkk turbo.

xantiaman how much boost do you give the engine?I read on other sites that 17 psi with standard intercooler will be fine.I fitted a boost gauge and it's 13psi which I think it's standard.Do I notice any difference without adjusting the diesel bolt (under the black box)?

Mine was about 15psi, accounted for by the extra fuelling (which raises the boost). It had a Garrett on it, and i must saw for a heavy car it went extremely well and always got about 43mpg.

I'm currently waiting for my new shiney plasma boost gauge to arrive, then i'll be tweaking my boost and fuel settings and reporting back. Also planning to gain access to the max fuel screw, but will only be playing with the boost pressure and on boost fueling to start with. I'll get pictures and make a mini how to.

On a 306 you can safely go to 17-18psi on stock intercooling, but they only have a teeny weeny top mounted interwarmer, 1.9 406's have a mahoosive front mounted intercooler so boost pressures can be a run a little higher, up to 20-21psi at a guestimate. I'm going to aim at 18psi and about normal levels of smoke first and run it like that for a while, then tweak a bit more if i feel the need (a quid says i will )

Tweaking these engines is really, really easy, made more difficult by the stupid attempts to stop us tweaking them!