mafless tune

Hello,
I've bought a swapped Golf MK2 with a AFN engine but it smokes a lot. Just turning it on will send a big puff of black smoke.
This car has no MAF, adding a MAF and obviously a new tune could help me getting rid of the smoke?
It really doesn't smoke much under full load but partial throttle load and gear changes are terrible

Just have whoever tuned the car turn the fuel down it doesn’t really need a MAF it just helps with better efficiency on a stock motor


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Do AFN have mechanical injection pumps?

AFN and AHU are basically the same engine, for the most part. Same IP, i think, same process for tuning anyways. Im not 100% on the differences but for the most part, same engines.
You need a VAG-COM cable and VCDS and a laptop. Look up hammer mod. You can back off the (QA) quantity adjustment the lower the number the more smoke/more fuel you get, the higher the number, less smoke less fuel, well in a 101 nutshell of the sense.
You can hammer mod with out this but only to lower QA, its difficult to raise the number without.
It wont make the smoking all that much better but it should help.
What size nozzles? is it stock? What PSI and turbo? stock?
You can always up the PSI a tad bit, this will help with smoke also but more than 1-3 PSI too much and you will go into limp mode often.

The previous owner said it has race 520 nozzles he wasn't sure if the pump has been upgraded. It's boosting around 30 psi with a 1756vk and also has a piper 260 camshaft.

Thanks for the tip about hammer mod, I will look into that.

MAF could be removed from software. Removing MAF will not increase smoke. This is one of most common mods for every tuned tdi´s, and it´s usually done even before changing any parts for avoid MAF-based problems. Very common mod for stock engines too for same reason, or for fixing broken MAF with it since price is around same.

Strange thing is that actually there is a maf connected to air box but with the plug disconnected. Not sure if this maf connected could handle the airflow on this build.

I've finally got the time to connect it to vag com and found that IAT is missing, so IAT reading always shows 75ºC could some fuel enrichment map being overcompensating for the lack of IAT sensor?

you can tune it to run smoke free with or without MAF
it is a little easier to tune with MAF as it'll automatically compensate for cold/hot weather, but you do run into needing a bigger housing eventually
vr6 MAF is something like 2.9" ID, volvos came with slightly larger ones, and then you can get aftermarket housings that are even larger

some guys just run the stock maf, then put full fuel up near where the MAF runs out of range so while it does smoke flat out, it is still smoke free for in town driving

[486] said:

it is a little easier to tune with MAF as it'll automatically compensate for cold/hot weather

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There´s always temperature compensation available on MAP based tune also. It is wise to use it.

You really need to sort out the tune, if the pump voltage map is properly calibrated then tuning without a MAF sould be fine. PV maps are the difficult bit !! don't be hammer modding the pump a properly tuned PV map will sort the smoke !