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Model specific boards => Golf mk4 => Golf mk4 TDI => Topic started by: arnoldlog1 on 30 October 2007, 18:33

Title: top speed problem, maf??
Post by: arnoldlog1 on 30 October 2007, 18:33

i've got a gt tdi 130(2002), it's great had it a couple of years now love it, but i've noticed i seem to have a top end speed problem. when i first had my car my car would accelerate really well to about 120mph, (on a private road of course officer!) but now i get to about 100mph and i really struggle to get it up any higher. I've got no other issues with the car my mpg is great, i average 50 ish, no fault codes.

any ideas? i was thinking could be maf but i though i would see a difference in every gear, and i can't, thought it might be wheel alignment but i get no vibration from the steering wheel, and i get even tyre wear.

any ideas????

Title: Re: top speed problem, maf??
Post by: Rhyso on 30 October 2007, 19:48

when was it last serviced?

dodgy MAF normally results in worsening MPG; does it feel flat at any point in the rev range?

have you checked for air leaks etc and you could be loosing pressure albeit in tiny amounts

Title: Re: top speed problem, maf??
Post by: arnoldlog1 on 30 October 2007, 20:20

no thats what i can't work out it's not flat at all, it revs really well no flat spots. mpg is fine if anything getting better mpg now(maybe i don't drive it as hard as when i first had it).
it was last serviced 3.5k ago by my local vw specialist.
had a check round no signs of any air leaks.

Title: Re: top speed problem, maf??
Post by: caddy vantastic on 31 October 2007, 13:47

Possible Map sensor fault. That causes the same effects you are having.

Title: Re: top speed problem, maf??
Post by: arnoldlog1 on 31 October 2007, 20:46

can anyone explain what a map sensor is? and more importantly what it does?

Title: Re: top speed problem, maf??
Post by: Rhyso on 31 October 2007, 20:49

this thread may help??

http://uk-mkivs.net/forums/thread/1062710.aspx