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PhatVR6

21MPG

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I've heard of that happening if you don't prefill the tensioning bolt with oil, but otherwise I can't see how it would jump. The lower tensioner is on a ratchet, so shouldn't move. Hmmmm......I wonder how many VRs are out there running 1 tooth out or with bent woodruff keys in the camshafts?

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I did prime it and bleed it, 3 times. I can't see it being that, but I'm not ruling it out without checking it.

 

My mat had his head done under warranty off the garage he bought his Vr off and they got it a tooth out too. It took him ages to work out it was that which was causing him trouble.

 

I'll try the MAF, but in all honesty, the cam timing being out produces all the symptoms I have, and it'd explain the lumpiness and the sounding like a WRX, the bad mpg, the weird ignition timing readings, and the loss of power.

 

they don't have woodruff keys in the camshafts, the have a slot, and the key is part of the cam sprocket (which are both brand new on mine, as are the chains and tensioner.)

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nearly 32mpg on the run back to Liverpool(ish!) back from inters, and that was carrying 4 wheels aswell! :)

 

yours dont sound right Phat, but letting it have a chance to run in like that man said might make a difference :?:

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When my MAF took a trip south, mpg was awful and so was the responsiveness. The ECU will load the limp mode if the MAF is shot, which is retarted and extra fuel by default. And due to Motronic 2.9 being full of bugs, it won't report a faulty MAF. I've even had my iffy MAF put on a scope at my local bosch tuner and they passed it, and yet the car ran horribly.

 

The words fickle and bag of shite spring so readily to mind.

 

I'd be surprised if the cam has skipped a tooth to be honest.

 

K

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Well, I too would be surprised if the timing was out. I've done 5 VR6 chain jobs, I know how to time them up. I checked this one 4 times. primed the tensioner up and bled it thoroughly too. I've even got the proper VAG cam timing tool too. Hell, I could write a book on how to time the vr6 up. The onlt thing I can see throwing the timing out would be the mk4 head gasket.

 

I've got another MAF, so I'll try that once I can get this fecking Derby started and out of the way.

 

As always, I'll keep you posted.

 

If the MAF doesn't sort it, I'll check the timing when I'm putting the schrick on.

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Paul,

The other thing you can consider looking at is the Lamda probe & associated connections as I understand that the ECU automaticaly defaults to "safe" mode (i.e. 15mpg!) if there is a problem with that.

 

Just a thought.

 

John

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(Well we've already ascertained that the lambda is being fed fresh air, rather than exhaust gas, so will be reading utter nonsense..)

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and it's the 8v lambda probe too..........which probably doesn't help.

 

Also, I had to put a new plug on the loom for the lambda, as it was missing, and I had nothing to connect the screen wire too? so maybe it's not working right.

 

VAG-COM didn't pick it up as a fault though?

 

I'll try all I can, if nothing improves then I'm going to have to get it on the rollers and see if they can tell me anything.

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check your engine's earth... you know the score with it, make sure it's clean, got a good contact with the gearbox, and is tight and hasn't gone green and cruddy.... :?

 

I've seen all sorts of running problems that were down to naff earths... :roll:

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No crud on my car alnywhere. and all the starting and charging cables are 5000v rated with gold plated connectors.

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Cool... I'd have expected nothing less from you Phat, but I though that I'd chip in anyway just in case you'd missed something... ;) 8)

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Well, that's what annoying me. I've either replaced or totally refurbished every part, nut and bolt in the engine bay, and it's goes and does this on me. So frustrating :mad:

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I know that feeling well matey... ;) Betcha it'll turn out to be something really simple... :roll:

 

Good luck... 8)

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Could it be down to the chip in your ecu? I remember you had to change your ecu, is it for the 2.9 or is it from a golf? With the 268 cams and head flowing it may just not be able to cope. :?

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I cracked 453 miles out of my tank from inters to edinburgh at the weekend was siting very steady 80 all the way with one stop. was well pleased after 9 hours driving. :lol:

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On the way back from Inters I got an average of just under 34 mpg :) Its better than I'm used to (but I was feeling ill and not driving too enthusiastically). I guess the run up to Inters may have given the engine a nice workout. I usually do the daily commute to Heathrow and back (30 miles of rush hour traffic).

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It's an AMD chip, which should be perfect for the 268 cams and flowed head.

 

The more I drive it the flatter it feels. I must be 50BHp down, it won't pull in 6th at all.

 

Still no error codes, down to 18.6mpg now.

 

I'm checking the timing on saturday.

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my brothers had a similar problem, did you change the air flow meter in the end? thats what was wrong with his but theyre about £300 so try and get another one to check it with first

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but theyre about £300 so try and get another one to check it with first

 

Or £150 from a Bosch authorised outlet.

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get your lamda tested. i.e. an emission test. Mine was faulty didn't realise til MOT time increased my ave MPG by about 30-40% :D

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