B5 Tip fitted - No gains according to MAF :( Is my MAF dead?

[Splab333]

I just fitted my B5 TIP and jetex filter, it sounds awesome and the car seems to breathe so much better at high rpm and more responsive everywhere, i'm sure it feels better and i'm really happy with it but I have disappointing g/s still....

It's a 2001 AMK S3 with Custom Code stage 1 map, I logged a 3rd gear run just before fitting and got 190g/s, pretty low compared to some others with the same basic mods but I fitted the TIP, it went perfectly, everything is a nice tight and secure fit. I've been driving round with a grin on my face since fitting it until I logged it again today, and got the exact 190g/s as before? Does this suggest my MAF struggling to deal with life nowadays!?

Is there any other tests I can do to diagnose the MAF without buying a new unit?

Thanks for any info

 

[<tuffty/>]

Stage 1 remap should net at least 200gs on average... it would suggest the MAF is a little tired... you could try unplugging the MAF and see if the car feels any different....

<tuffty/>

 

[Splab333]

Ah cool, i'll give that ago, thanks for such a quick reply, should it feel faster then? I mean would a tired MAF be holding back things? Sorry for the questions, i'm still learning!

 

[superkarl]

yeh a ******** maf will make the car feel dead.

my car is on a standard map and i get 191g/s consistently, so id be worried about your maf.
unless its not actually mapped?

 

[Splab333]

It's definitely mapped as I had it done myself, i'll go out in it in a minute and see what the difference is with the MAF unplugged.
So if the MAF was limited to sensing 190g/s, and say my car was actually seeing 200gs+ would it be running lean or pulling timing? Or would it just mean that the turbo is getting more flow than expected and making life easier for it?
Is there anything I should log whilst the MAF is unplugged?

 

[<tuffty/>]

If its under reading then you may see that fuel is being added to the fuel trims (block 032).... if you are getting 200gs of air but MAF is reporting 190gs (under reading) then the ECU will fuel for 190gs but lambda will see it as lean and add fuel through trims...... block 001 gives live lambda adjustments so it may show up there too as it adds fuel to meet requested lambda

<tuffty/>

 

[sideways steve]

This is the same issue I have been having with my 2001 AMK engined S3. I have carried out various checks and I am pretty sure my MAF is goosed. I will be replacing it sometime soon.

 

[ads1377]

Do I need special tools to measure the MAF reading?

Thanks

 

[<tuffty/>]

Do I need special tools to measure the MAF reading?

Thanks

you will need software like VCDS..

<tuffty/>

 

[ads1377]

Ok Cheers

 

[sam4191]

This may help, but I had troubles with my MAF, and was giving 192g/s. (Stage 1) Unplugged it and it went well again. So bought a new Bosch one and wow! Like new, smooth and quick and 210g/s. It's amazing what a screwed MAF will hold back!

 

[Splab333]

So I was unable to drive my car for a few days and only just had a chance to log fuel trim etc, here's my results:





Also, my requested boost vs actual boost that i'm still not sure about..... i'm still down by a few 100 mb from requested? On the good side though I got 5bhp extra with the maf g/s reading because of the TIP and JR filter but no where near what others are getting from it!

Any input on the fuel trim and O2 would be awesome, thanks to everyone for the help so far

 

[Splab333]

This may help, but I had troubles with my MAF, and was giving 192g/s. (Stage 1) Unplugged it and it went well again. So bought a new Bosch one and wow! Like new, smooth and quick and 210g/s. It's amazing what a screwed MAF will hold back!

Oops, I replied using a tab I had open earlier! I still need to do a run with no MAF, is there any point in logging data while I have the maf unplugged too or shall I just see if it goes better? How much will a new bosch MAF be? Thanks

 

[Sam_]

I got one off eBay in the UK and got it shipped here. Make sure it's genuine Bosch, there's a lot of crap on there. It was about 100 quid from memory. Made a decent difference on mine too but hard to tell as I changed loads at the same time.

 

[Splab333]

I got one off eBay in the UK and got it shipped here. Make sure it's genuine Bosch, there's a lot of crap on there. It was about 100 quid from memory. Made a decent difference on mine too but hard to tell as I changed loads at the same time.

Yeah, I have read the horror stories of the cheap MAFs that make problems even worse sometimes! I have a mate with a standard Cupra R so maybe i'll see if we can log a run in that and see if it gets close to 180 g/s (i think it's 225bhp) then maybe I can swap the MAF and log mine. I just want my car right again!

 

[Sam_]

Or nick his MAF and give it a go in yours?

 

[<tuffty/>]

Hummm... fuelling wise you need to log block 031 not 032... should have been a bit more clear on that... you only need to look at block 032 after a run or two to see where the fuel trims have settled...

Airflow is down but thats partially due to load dropping off... don't know why as its not obvious from the logs... from 4.8k on load drops off from 191% and continues to drop... this is not what should happen normally...

Not sure what could be causing it but it could be a poorly MAF if you haven't changed it already... I would be logging block 020 too for checking timing pull... what fuel are you using?

I have to say there is no way the B5 tip is the issue here mate... there is clearly an issue with the engine somewhere... just need to find it

<tuffty/>

 

[Splab333]

I have to say there is no way the B5 tip is the issue here mate... there is clearly an issue with the engine somewhere... just need to find it

<tuffty/>

Ah no, I never intended on blaming the TIP!!! if it gave me 1bhp i'd still be happy, it's awesome build quality and sounds great! I know that my problems stem back far before the TIP and the map as it is just a generic CC map! I know it's my car in particular and I need to get to the bottom of it. I'll log the blocks you suggest again and go from there thanks for the help, you're a beast.