Thread: How to completely get rid of MAF on de-EGR'd TD5

Also keep in mind the OP is only playing with a manual vehicle

Originally Posted by dswatts

I tried this mod this morning.
I have a remap, a autologic "power" map which gives me really high EGT's.
Easy to hit 900-1000c ( I don't ) so hard to compare, but I'm pretty sure EGT's were 50-100c higher under the same road conditions.
What really stood out was surging, Kangaroo hopping which went away when I removed the link and plugged the MAF back in.

Just my observations

Dylan

Given you already have a remap, sounds like you have confirmed this mod can result in additional fuelling which could result in more performance for a stock motor albeit in a crude manner but not suited to a remapped ECU. Also would support that the MAF is part of the fuel rate calculations.

The "European strap ons" have the same impact when set with too much additional injection time - especially under light acceleration as you get too much fuel.

This mod also sounds like a simplified version of the RonBox2 which if I understand correctly just manipulates the MAF and MAP outputs to trick the ECU to inject more fuel.

Would be interesting to hear from someone who could trial on a manual with a stock ECU map but with the EGR removed and of course with an EGT to ensure you are not over fuelling.

If I've read correctly it's not necassarily a physical de EGR (surely that's not a word) but the EGR must be switched off in the map/ecu?

If it's switched off the values from track 1 on TPS keep it happy (well still being worked through in this thread). If it's not switched off then any voltage anomaly from the MAF eg unplug it, will throw an error and a subsequent limp mode

i'm not blindly following the book just starting from the presumptions that i can rely on the important and clear statements from there... off course that where there are contradictions i use muy own mind and logic to get to a conclusion... like the MAF's description

Originally Posted by Dougal

You don't know how a MAF works.

I'll give you a clue. It measures mass flow already compensated for temperature difference.

thanks for the clue ... i think you confuse the MAF sensor with a computer though,...it's a simple resistance setup and outputs an analogue VOLTAGE signal, if doesnt "compensate" anything, as the heated element in it is cooled by the air flow it's resistance drops and the voltage rises... it's about air flow drawn into the engine(if we can rely on the book and on reality)... here i have a contradiction to the book(to show that i'm not blindly following it when i think it's wrong) cos IMO it's exagerated to be named mass air flow meter cos in reality it's just an air flow meter ... if it's like you said that "It measures mass flow already compensated for temperature difference" , i'm asking temperatrure difference compensated by what? ... and then why on those cars where the book sais the MAF is mainly used for engine management there is a IAT on the same port? i say cos the ECM calculates the mass based on the air flow and the temperature readings and the built in software "compensates" for that...
V8 description: The MAF/ IAT sensors are combined into a single unit and located between the air filter housing and the inlet manifold.
The ECM receives input signals from the MAF/ IAT sensor to calculate the mass of air flowing into the engine inlet
manifold.

so even if the book contains omissions and even inacuraties (which i agree) then why for the V8 the description is so different than for the Td5 and slightly different than Td4? cos if it was the same for all they should have copy/paste'd from one to another to keep the things simple?

maybe i dont know how the MAF works but then everything about it in RAVE is inaccurate so we could bin it without remorse.

Originally Posted by dswatts

I tried this mod this morning.
I have a remap, a autologic "power" map which gives me really high EGT's.
Easy to hit 900-1000c ( I don't ) so hard to compare, but I'm pretty sure EGT's were 50-100c higher under the same road conditions.
What really stood out was surging, Kangaroo hopping which went away when I removed the link and plugged the MAF back in.

Just my observations

Dylan

thank you for trying it... yes i must admit that all those who made it including myself have manual modells... please tell me what other mods beside the remap you have on your car?

Originally Posted by sierrafery

thank you for trying it... yes i must admit that all those who made it including myself have manual modells... please tell me what other mods beside the remap you have on your car?

EGR removed and muffler taken out. That's all

i'm asking cos off course i'll modify the title too in case if it's not suitable for autos but i want to understand what's going on... by removed EGR you mean unplugged modulator too? also what i forgot to say is that my ECM is remapped by specialist for the non-EGR setup so i'm thinking that this is important too(i admit that based on my own experience i didnt think so deep... that's why any oppinion is important and i dont mind even if it contradicts me... do you get "EGR stuck closed" fault code when you plug in a tester?

even if it seems contradictory at some points this discussion is good cos we'll find out important things together and off course i'll reconsider/addapt the whole thing accordingly... it's far from my intentions to misslead anybody to do something wrong or dangerous... it's not excluded that at the end of this "debate" i'll be the one who will say "F**k it, it's not good"

by the way, sorry but what's the "muffler"? it exceeds my english

The MAF measures air, there's temp sensing and that and other stuff combines in the ECU which compensates IN ITS Calculations of fuel delivery. You're correct in that but I think that between the two of you there's just a mis communication of the compensation. The MAF is a tool for measurement calculations and compensations occur in the ECU.

I am curious about the remap suited for non EGR as I don't believe (Tombie?) most maps used here are altered either way.

Dougal: I had a gas analyser on it. At idle the hydrocarbons are out of measurable range, at 2500rpm and up and at cruise from 85 km/h and up it's cleaner than a D3 and has great economy. But most driving is city and well...

Muffler is silencer (centre) the one at the rear is a resonator.