Tdi running problems

[Dodson]

Hey guys first time with a tdi, i seem to have a big problem, wen i put my foot down hard i get a massive flat spot at about 2.5k and the car wont rev past the flat spot. It feels as if the turbo disappears and is non existent. I can here the turbo spoolin and if i accelerate smoothly it revs right round. Lookin for some advice please guys.

I hav been told it could be either the maf or hoses.

Jus had car vag com'd and there is no faults.

Oh and its a golf gttdi 115 thanks

 

[glynnd]

Sounds like a maf problem for sure.
They are about £65 plus vat exchnage from seat.
Maf problems as a rule do not give a code with vag com

 

[daveyonthemove]

Try driving without the maf connected to compare the drive.

 

[daveyonthemove]

Maf problems as a rule do not give a code with vag com

They do when i have checked them in the past.

 

[Dodson]

Would a maf off a 225 s3 work on my car jus to try before i buy one? I tried drivin wi it disconnected and it made no difference jus felt flat.

 

[daveyonthemove]

If it felt flat then that is how a car with a broken MAF drives. So if it made no difference then your maf is looking like it's on its way out.
I don't know about an S3 Maf working on a TDI, i would doubt it but try comparing part numbers. If they match then you're on to a winner.

 

[glynnd]

I would be very suprised if an s3 maf worked on a diesel!

 

[sssstew]

im thinking MAF too, i would log requested vs actual with VAG COM and see if its dead, see here :-

http://www.ross-tech.com/vag-com/cars/tdi.html

I would say no, a petrol MAF will not work for you.

 

[cheshire cat]

If it felt flat then that is how a car with a broken MAF drives. So if it made no difference then your maf is looking like it's on its way out.
I don't know about an S3 Maf working on a TDI, i would doubt it but try comparing part numbers. If they match then you're on to a winner.

if it hasn't improved it is less likely to be the MAF I would look elswhere first and don't confuse things with a non standard one

 

[daveyonthemove]

I found that my car drove WORSE with no MAF on, so i would expect a car with a dodgy MAF to drive equally as bad?

 

[cheshire cat]

I found that my car drove WORSE with no MAF on, so i would expect a car with a dodgy MAF to drive equally as bad?

worse than what? conventional wisdom says it will drive better with no MAF than a duff one as it reverts to a fixed value

 

[Viking]

There's no definate line where you can say a maf has failed unfortunately. They can give good performance but a flat spot in mid range, they can fail over the whole rev range, they can lose performance at the top of the range, and may or may not throw a fault code with any of these conditions.

So, if your maf just has a flat spot problem, then disconnecting it will give you worse power but without the flat spot. If it's failed across the whole rev range then disconnecting it will see an improvement or stay the same.

Only way to tell is with Vag Com or swapping for a known good maf and comparing.

 

[Dodson]

well i get paid tomorrow and was going to go and get a new maf from VW.

I just hope its the right thing to buy!!

 

[sssstew]

only vag com could tell you that for sure.

 

[Dodson]

Well i have bought the maf today. Just before i fit it. The car has jus been runnin so much more better with less flat spots and nearly runnin perfect. Its really strange.

Also its above 25 degrees c today and im wondering if that has any coincidence with the way the car is runnin? Thoughts please thanks

 

[Dodson]

Well iv jus been and fitted my new vw supplied maf and all i can say is wow!

The maf was definately broke. I hav fitted the new one and it feels bloody rapid now.

So jus to report back it was defo a failin maf that caused my problems. Thanks for the advice. Lee

 

[daveyonthemove]

Glad you've got it sorted mate.

 

[sssstew]

yep good to hear, glad its back to normal.