PD130 EDC15P MAF-MAP switching question

**Marge** · 13th May, 2018, 07:29 PM

Hey,

I have a Golf MK4 TDI PD130 EDC15P

It s currently stage 1 tuned with little to no smoke.

Today I have switched from MAF to MAP sensor and adjusted the MAP limiter to suit but is now badly smoking but still drives well.

What is the cause of this and what needs adjusting/calibrating to reduce the smoke back down?

Thanks

**morgano** · 13th May, 2018, 08:46 PM

Just fill MAP based smoke limiter with right calculated numbers.

**Marge** · 13th May, 2018, 11:52 PM

I have increased the MAP limiter to suit the tune but it still smokes

The only thing I can see being the issue is the MAF smoke limiter being controlled by airflow mg and MAP smoke limiter would be by boost pressure which of course be different so there surely needs to be a recalibration with this?

**morgano** · 14th May, 2018, 08:08 AM

If it smokes you are allowing too much fuel to enter before there is enough air to burn it properly. The more you increase MAP based smoke limiter the more smoke you will get. Try lowering it. Or calculate it to 17 afr and it should not smoke.

((EngineCC/4) * (Boost/1000)) / 17

That will give max value to each column in map based smoke limiter.

**Marge** · 14th May, 2018, 03:27 PM

Yes I have done this correctly.

calculates to 71.25 so have set limiter to 71

It's where the MAF is limited by airflow 300 to 1051 and MAP is limited by boost pressure 800 to 2000. Will these changes of control axis have an effect at all?

**morgano** · 14th May, 2018, 05:07 PM

That 71.25 mg would require 2.55 bar boost on 1.9 tdi engine or 2.42 bar on a 2.0 tdi engine.

If your map axis only goes from 800 to 2000 then you have your answer why you get smoke with 71 iq.

Rework the axis to your new boost numbers and populate the map correctly using the formula i posted for you.

**Marge** · 14th May, 2018, 10:40 PM

Yes that would make alot of sense. I will try this out and let you know

Thanks

**Marge** · 15th May, 2018, 08:04 AM

So when changing MAF to MAP sensor, does this change the X axis on the smoke limiter map from airflow to boost pressure data?

**morgano** · 15th May, 2018, 10:37 AM

Originally Posted by Marge

So when changing MAF to MAP sensor, does this change the X axis on the smoke limiter map from airflow to boost pressure data?

No.

The MAF based smoke limiter is then out of order, you need to find and correctly populate MAP based smoke limiter. They are two different maps, but close together.

**Marge** · 15th May, 2018, 11:16 AM

Originally Posted by morgano

No.

The MAF based smoke limiter is then out of order, you need to find and correctly populate MAP based smoke limiter. They are two different maps, but close together.

Ok so reworking the MAP based smoke limiter to become the new smoke limiter? Re calibrating the boost pressure axis and IQ data?

Image attached

I appreciate the help