Hi all,

I have a VRS Mk1 that has done 110k miles which is proving a little tricky to sort out. Occasionally in 1st and 2nd when accelerating it will kangaroo or hesitate to pick up for a second then runs smoothly. It also seems to have a slight loss in power, nothing major but enough that i have noticed, it also idles at about 700rpm but every 5 seconds ish will just fluctuate then settle again.

So far i have checked all turbo pipes, nothing found.

Changed upper and lower breather hoses as they had splits.

Changed all plugs.

Changed fuel filter.

Added a bottle of petrol magic to tank to give it a bit of a clean.

Changed coolant temp sensor.

Ran with MAF sensor disconnected. (Made no difference to how car ran, does this mean its shot or ok?)

It has flew through MOT with no codes showing on scan.

I have it booked in for a new CAM belt, pump, thermostat and seals as this is due. Could this cause the problem if they are worn?

Any ideas on what i can check/change next?

If running without maf made no difference it would suggest its goosed. Mine had been doing similar recently and had theorem up a code which points to maf.

Mine also sailed through its mot with no issues.

Apparently its got to be genuine maf as others will fail.

Cleaned throttle body?

I had the throttle body cleaned at its last service so that should still be fine.

I drove the 10 miles to work today with the MAF disconected and there was no difference in the way it ran. If it was working then surely there would be a notible difference when its unplugged. I dont want to go spending 60 quid changing a part just for the sake of changing it.

What is your plug gap?

Have you checked that the coil packs are the current type?

Coil packs are fine.

Had it running on NGK plugs gaped to what was stated in Haynes manual, can remember of hand. Its now running on BOSH super 4's. Made no diference either way.

I have noticed the sound of the Turbo spooling between 1500 - 2000rpm but cant remember if that wah always been there or its just me listening for more noises etc.

Have you tried running with traction control turned off

No i havent. Will try on the way home from work? Doesnt the traction control shut down when the MAF is disconected tho?

Cambelt/thermostat wouldnt cause this. was the coolant sensor changed for a dealer supplied one?

If the MAF is shot then you will notice no difference when disconnected as it is not doing any thing anyway. If it was working correctly then you should def notice a difference when you disconnect it.

Well im positive it is the MAF now. Drove home, CEL light cam on along with ASR light. Must have switched back to default settings and it pulled like a train and was as smooth as you like. Plugged MAF back in to check and i managed to kangaroo 50yards down the road where i had to pull over and unplug it again. Once off again it was like driving it from new. It had lost a hell of a lot more power than i first thought. New MAF will be fitted tomorrow.

Thanks for the advice guys. Any ideas on why the turbo spooling has gone loud

hope it works for you mate let us know

Any ideas on why the turbo spooling has gone loud

Have you upgraded the air filter at all

The aftermarket ones allow a bit more turbo noise through

Have you upgraded the air filter at all

The aftermarket ones allow a bit more turbo noise through

I was wondering the same.

Oh and the MAF needs to be a Bosch one to last.

Everything I have changed has been original parts including the air filter.

I have picked up an after market MAF tho, i have a CAM belt change to pay for so didn't want to spend too much this month, will get a Bosch MAF in a couple of months.

I have read a faulty N75 valve can cause the spooling to play up, is there any truth behind this and is there any easy way to test it?

I have read a faulty N75 valve can cause the spooling to play up, is there any truth behind this and is there any easy way to test it?

They can and no there isn't ..... Sorry I can't be of anymore help, whereabouts are you located, maybe someone near can help you out with a swap on a good one.

Im in Tamworth. Eurocarparts are doing the N75 valve for 40 squid so i'll pop a new one on next month. The car is a 54 plate and nothing lasts forever, its at the age and mileage where things are just worn i guess.

FYI, My N75 has 150k and is still fine !!!

Try and swap it first, you'll probably save £40

Have you ever cleaned yours? Apparently you can disconnect the pipes to it, add some short lengths in there place, turn the ignition to on and spray a bit of carb cleaner down each pipe.

I had very similar symptoms , I tried changing the maf , when I unplugged the maf it worked fine , so I got a new maf and it still did it . It turned out to be a dirty throttle body .now everything is fine ! I know you have had it cleaned recently , but mayb it's worth a look ?

Never cleaned it but swapped it for a known working one today and I still have the same issues as before. So mine is fine.

I'm not sure about cleaning it never heard of that one

I have use this every so often

http://www.ebay.co.u...=item589d5dd777

Edited 13 March, 201313 yr by mluton

quick update for you. new MAF fitted. Hesitation has gone now. Mrs kept telling me to slow down so i guess the power is back too. Will still give the throttle body a clean when i get chance too. I can live with the hairdryer sounding spooling for now. Crazy thing is you can hardly hear it in the passenger seat. All in all im a happy camper for now. Thanks for the help guys.

oh, how long does it take for the ecu to recognise the sensor is back and the check engine light to go out?