MAF MOD with diode...

Do you have VagCom/VCDS? One way to tell if you have it wired correctly is to check your MAF readings. If done correctly, an ALH/A4 will be maxed out and fixed at 1275. Being your year and engine code, I hope you checked your voltages and pin-out's first before just jumpering. There is some risk of doing it wrong and damage.

I think I will try this on my Pd.
I have a TDI PD engine and the MAF readings are realy low.
With stock map, the max value is 984 ish.
With modded map is going to 1100 ish ,but after 3000 RPM is going down.
Off course I have tried many MAF senzor's, witch in other cars are working great.
Pressure of the turbo is not dropping ,I do not lose pressure, but I don't know what is causing this.

FlyTDI Guy said:

Do you have VagCom/VCDS? One way to tell if you have it wired correctly is to check your MAF readings. If done correctly, an ALH/A4 will be maxed out and fixed at 1275. Being your year and engine code, I hope you checked your voltages and pin-out's first before just jumpering. There is some risk of doing it wrong and damage.

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no vcds yet there's no cel but I will check voltage and go from there

yeah I think its noticeable now it pulls hard all the way to redline and good low end power I just did the every mod and about to go for a ride and see how it is

vw 1.9 tdi 110 pr maf off swich and map linearization 4 bar

I read your discussions . I would like to act on the map ecu to eliminate maf and linearize the map from 4 bar absolute . Do you have any useful information ? My car and the engine is mounted msa15 AHF . Thank you

? Help me

Today i install this 1n4148 diode to my audi 2.5tdi ael. Well it worked black end to pin 2 other head to pin 3 enjoy.

To87 said:

Today i install this 1n4148 diode to my audi 2.5tdi ael. Well it worked black end to pin 2 other head to pin 3 enjoy.

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put the pictures that are curious to see how you do? thank's

When my tune was flashed on my 2001 TDI, the requested MAF is set at 850 whether it is at idle or at WOT, and if I start the car and then unplug my MAF, I am told the ECU goes to maximum fueling.At present I have .205 injectors and a Stage 3 tune (18 PSI).
Will a 1749v (vnt-15) produce more than 850 at WOT? I believe I never actually looked at that graph before. The one odd thing though, is my MAP is 100mb below requested at idle and 100mb higher than requested at 60 mph. I am trying to figure out why my ECU isn't matching the request in either situation, any ideas?
While graphing my MAP and N75 values the other day, the N75 plot had a giant spike in it right along with the actual MAP. The odd thing was the requested had a nice flat line along the WOT, but the actual had a downhill slope directly after the spike came out. Once again, any ideas?

Max is 1275. You can reach mid 11xx w/VNT-15 & Stage 3 tune. If you're locked down @ 850, you may be getting shorted on fuel on WOT. My tune shows 850 constant as well. I do not have a MAF delete (via tuning) with the tune (AFAIK) and the car responds to MAF output. Watch your actual MAF output as specified is not what the ECU is going to act upon. Contact your tuner for clarification.

FlyTDIGuy, thank you for responding. I may be a bit confused...Since you also have a 850 constant, I know you understand. What I have not done is unplug my MAF after starting the car and see what it says on Vag-Com and then plug it back in and go for a romp. As far as 1275 being the max, is that written in stone? What I mean to ask is will a 17/22 and bigger nozzles "outrun" the 1275 MAF, or can that variable be changed with a re-flash on my ECU?

1275 is the number reported if you jumper the MAF as suggested in this thread. I suspect the MAF is saturated at that number and incapable of reporting anything higher. Running a 17/22 @ 28 PSI, I have not exceeded that limit.

If you unplug the MAF, you will see a 'flatline' response of 550 as the ECU will substitute a default number. It thinks there is a fault in the system as the MAF is not responding as expected. A midrange number is set by the ECU under those conditions to allow you operate somewhat normally. I don't believe your experiment of unplugging the MAF, then re-plugging it in will offer much in the way of useful info or performance.

What I said was confusing, I apologize. What I meant to say was; I was going to see if my MAF went to 850 when unplugged, and then plug it back in and see how high the MAF reading would get on Vag-Com in third gear at WOT. I did not mean to imply I thought something would make the MAF read differently by un-plugging and then plugging it back in.

I believe all the information you need is in my last post. Make sure you are clear on Specified vs Actual. The 850 you refer to should be Specified only. It will not change, MAF plugged in or not.

Thank you for your help. I just unplugged my MAF and Vag-Com said 1275. I can't say If I noticed any difference in power or not, but I did not have any noticeable smoke at part-throttle or at WOT.

joseph pivot said:

put the pictures that are curious to see how you do? thank's
Here it is maf plug and diode (a6 c4 2.5tdi).

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jpderv said:

if you want to dissable you maf just flaten your smoke limiter like this

and youl be able to unplug your maf with no problems no limp mode etc works on all tdis with an ecu.

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Really?
I assume he meant to set smoke limiter over torsue or driver wish while runing a map based tune.
Anyone experienced it?

moivw said:

Really?
I assume he meant to set smoke limiter over torsue or driver wish while runing a map based tune.
Anyone experienced it?

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No, this work only with some software that use both maf & map output for fueling. There's always a switch to turn off maf function to make a clean job.