no black smoke

jonesy · 12-09-14, 10:34 AM

mgzs td+115 sdi,s decat pipe,performance airfilter, under hard ecceleration I get loads of black smoke out the back and iam talking a smoke screen its that bad,but if I desconect my maf sensor I get no smoke whatsoever it picks up a little quicker but a bit slower top end,does this mean I need a new maf thxs for any replies....

talkingcars · 12-09-14, 11:09 AM

I don't know modern diesels but is the maf electric? Could you fit a switch to turn it on and off?

jonesy · 12-09-14, 12:06 PM

I think the only way to turn the maf off is to pull out the plug,just leaves the engine manegment light on on dash,strange that it stops it from smokeing,someone might know

ZS Phil · 12-09-14, 01:01 PM

Will it rev past 4k rpm? If not then the maf is the problem.

jonesy · 12-09-14, 03:44 PM

ill give it a try next time iam out,

Dan1971 · 12-09-14, 06:47 PM

Quite simply - sdis = black smoke.

Unplugging the MAF sensor will cause the hesitation at the top end, because that's what the sensor does - make sure that it pulls all the way through the rev range effectively. That's why when you've unplugged it - it's gutless. That shows that your MAF sensor is working fine.

The only thing you can do as far as I'm aware would be to get it remapped. That will help in relation to your upgrades and the smoke.

ZS Phil · 12-09-14, 07:04 PM

Just another thought, no mention of upping your boost? If you are running standard boost on sdis you will get smoke. On a non-mapped car with SDIs and 19 psi boost smoke should be nothing more than a light haze. Getting a remap for performance will not necessarily reduce smoke.

peterzs · 12-09-14, 08:49 PM

Boot it in 3/4/5 I get black smoke, does die away.

Specially useful for all the white Audis, that try and push me along.

jonesy · 13-09-14, 07:48 AM

I am running at 18psi just wondering whats the safest maxim boost I can go to maybe 20psi,i think if iam spotted by the the police giving out that much soot out the back ill get pulled,it completely blanks out any car behind me,just seems strange as soon as I unplug the maf I get no smoke,

Mark S · 13-09-14, 08:09 AM

All that black smoke will be causing bore wash too, the engine won't last long like that.

We used to run 2 bar on one TD (30psi) but its all down to the turbo, I doubt 2psi will clear up all that smoke?

Remap to get the fuelling right sounds more like what you need?

Is there not a bigger turbo that can be fitted to these engines? Or/and a higher pressure fuel pump?