engine judder

[bilko0795]

Hi guys
whats wrong tonight when driving the car on hard accelaration the car started holding back it would shoot forward then die back all the way up the road but when driving normal its ok Any ideas? wondering iff its a boost leak? it happened once before when i bought the car in sept last year it done it twice on the way back from Scotland but its been ok since even this morning when driving hard.

cheers.

[haaran]

Yea, sounds like a boost leak or possibly a dodgy MAF connection. Pull it of and give the pins a clean, and see if it makes a difference.

[s2driveruk]

yup, boost leak and it can be pretty violent too

[bilko0795]

Yup its pretty violent any ideas where i should start looking ie the most obvious place or could it be anywhere? and how do i test for a boost leak or do i go to a garage.

cheers.

[Rusty]

Need to get it leak tested. PM K_simmonds on here, he's closeish to.you and will be able help

[bilko0795]

Cheers rusty

[s2driveruk]

first thing i would do is ensure all the jub clips are tight (mine had a habit of slackening off over time and in the end i replaced them all which helped no end...then down to doing a leaktest as suggested, could be tired rubber pipework, vac lines or physical parts (my IM was leaking....WGFV had split, seen posts recently on leaking ISV's etc etc...)

Good luck, it can be painful to trace but the feeling at the end will be worth it. For a few quid, its good insurance to renew the vac lines anyway if they havent been done - posts on here about internal ID for the pipes.

[s2_bo]

Could also be knock sensors.
If its that extreme it would need to be quite a big leak or multiples. Should be easy ish to track down. Insect all the boost hoses and see if any are split.
Just have a feel around and see what you find. Hopefully it something obvious and easy to sort out..

[bilko0795]

Thanks for the info as im new to these problems im not sure where to look ie which rubber hoses, jub clip locations, iv valves, vac lines, turbo cars are a mystery to me .

cheers.

[bilko0795]

Right pulled the codes tonight and they are 00561 mixture adaption not reached, 00544 max boost pressure exceeded implausable signal inttermitant, 00513 engine speed sensor no signal (G28) drove the car today floored it and it was fine so any idea whats wrong?

cheers.

[K Simmonds]

Right just read through this and further to our phone conversion I'd say the following.

00513 engine speed sensor no signal (G28). Nothing to worry about assuming you did the VAGCOM readings with the engine off. Beside's it shouldn't start if that sensor is duff.

00561 mixture adaption not reached. This is most likely MAF related. Your MAF could be going bad, however if that was the cause of the judder I'd expect it to happen more often.

00544 max boost pressure exceeded implausable signal intermittent. This sounds like a problem with the vacuum piping to the N75, the valve itself or the Diverter valve. Could also be Waste-gate related. I'd start by checking out the pipe work, the N75 valve as well as the Diverter valve. This is most likely the fault causing your problem, you now just need to find the source of it.

Check all the small bore pipes, including the one going to the wastegate very closely. Personally I'd just replace the lot if there is any doubt regarding their condition.

That said a duff MAF 'could ' be the cause if it only decides to read funny occasionally.

Buying a new MAF at that price is a good idea. Can't see them ever getting much cheaper. If I were you I'd purchase one for piece of mind, you can then rule out that item completely. EDIT- Just noticed on your other thread that ECP are doing them for 150 delivered!

In fact I think I may have to snap one up to keep in stock.

The MAF's tend go out of calibration over time and a tiny amount of variation can make a massive difference to performance.

Edit- Thanks for recommending me Rusty

[K Simmonds]

Should also have mentioned I have good spare N75's, DV's and a MAF to hand.

Right must do some work.