Thought I'd fixed this but...............have'nt.

[robadobadob 0]

Had my first proper outing in the Vr yesterday, a trackday at Keevil airfield.

Had a friend in his Golf Mk3 8 valve and me in mine, both cars performed very well and were a hoot round this coned off runway BUT my VR still stops reving at 5000rpm.

This isnt a misfire or the hard cutout of a rev limiter but power simply tails to almost nothing above 5k, in 4th gear 5200rpm is all it will manage and then it will just sit there at those revs wether you use 1/2 throttle or full.

It feels like fuel stavation although it could be a faulty TPS I suppose.

Ive already changed the plugs, leads, airfilter, MAF (second hand but made no difference) and fuel filter but still it does this.

Plus my code reader is OBD2 only so wont comunicate with the car either.

Could the CAT be on its way out?

Thanks in advance for any suggestions.

[Daverse 175]

might be the fuel pump?

[russj249 2]

Blocked exhaust? See if it will hit the limiter if.you gradually raise the revs at a standstill. Gone through a phase of blocked exhausts at work recently for some reason

[robadobadob 0]

Nothing to see here.

[robadobadob 0]

Did have a quick thought, does the ecu have a limited performance mode, like limp home on a later car but with no check engine light?

[robadobadob 0]

Ok, this really is getting the better of me.

Have changed the following so far and they have made no difference whatsoever;

MAF, run the car unplugged and plugged in, no change.

Swapped it for a known good one, no change.

TPS, run connected and unconnected, no change.

Swapped throttle body with different good TPS, no change.

Cam sensor, removed and cleaned, no change.

Crank sensor, removed and cleaned, no change.

Exhaust sensor, run with connected and disconnected, no change.

Swapped exhaust for a stainless, twin box system, no change although its not exactly noisey......79 db at4.5k at a Kirby trackday.

Blue ECU coolant temp sensor, ran with connected and disconnected, no change, fitted new one, no change.

At the moment the car has no fuel pump fitted as I'm replacing it with a known good one to see if its fuel pressure/flow, will keep you posted.

Thought maybe the CAT was maybe half blocked but havent checked this yet.

The car will get to the redline in second but once it hits 5k it will take a further 10-15 seconds to cover the last 1500rpm to the redline!!

Just cant get to the bottom of this..............

[russj249 2]

I'd seriously drop the cat off the downpipe before anything else and see what happens then.

[VR6Pete 1,455]

You need to get VAG-COM / VCDS and run some logging minitoring the various sensors etc... and see what happens during that last 1,500 RPM. could be knock sensors retarding the map or anything really... you really need to look at the measuring blocks and analyse what is going on as opposed to just replacing parts

[robadobadob 0]

Thought this but my OBD reader only reads more modern cars and I bought a copy of VAGCOM of eBay and it will not communicate so short of taking it to a garage (I'm loathed to do that!) I'm a bit stumped.

Car happily revs up in neutral and runs fine except above 5k.

[brynvr6 1]

Deffinetly investigate a blocked cat, I have seen a very similar problem on a mk3 gti before.

[robadobadob 0]

Finally got to the bottom of this one..........

Bought a Japsport decat from Ebay for the car which ended up being a bit too short so was modified to fit and suddenly the car was a fair bit noisier, not horribly loud but just gruffer so took it out, on a private road naturally and.........it flies!!!!

The CAT looked ok from either end but rattled like a bag of spanners so this was the fault all along.

AND no one told me how good the VR motor sounds when it bumps the limiter!!!

Cheers for all the help.