boosting somtimes

[briso 101]

Hi guys just wondering if any can give me some advice please.

I had my car remapped in november it was all running good but now ive noticed that sometimes the car will not boost u put urfoot down and u can feel it trying to boost but holding back the boosting the holding back this is starting to happen alot now.

Sometimes if i switch thecar off andstart it again the problem goes but sometimes it takes a few off and on.

Could this be a problem with the remap do you think as if it is i can ring the and tell them to come sort it out.

many thanks guys.

[alex.hayes73]

Hello mate have a look at my post "Boost Problems" it might help

[jmf]

What exactly do you mean by "feel it trying to boost"? Any sounds or on/off pulling or what?

[KenONeill]

It sounds like the car is going into "limp home" mode.

I'd start by getting the fault codes read, and am half-expecting over-boost codes pointing to an N75 problem (vRS, not a TDi. This is why knowing what engine the car has is important to diagnosis folks).

[briso 101]

What exactly do you mean by "feel it trying to boost"? Any sounds or on/off pulling or what?

It starts to boost then stops then starts and stops jerking yeah it is makingall the noise it usually does

[Beretta]

Coil pack starting to break down perhaps?

[David 8]

N75 valve maybe

You need a scan on it really

[KenONeill]

It starts to boost then stops then starts and stops jerking yeah it is makingall the noise it usually does

So you're saying it's running rough, not just flat?

That suggests a misfire, which suggests coilpack(s) or plug(s). Again, fault codes. They'll point you to which cylinder(s) the misfire is on, and hence where the replacement is needed.

[scootie]

Clean the gas throttle body? Might be as simple as that.

[briso 101]

So you're saying it's running rough, not just flat?

That suggests a misfire, which suggests coilpack(s) or plug(s). Again, fault codes. They'll point you to which cylinder(s) the misfire is on, and hence where the replacement is needed.

Thats just it its not throwing any codes or lights up just splutters sometimes i run it on super unleaded just to be safe to just dont understand why its only sometimes

[David 8]

Have you tried umplugging the MAF and running it ???

Shot in the dark tbh.

[jmf]

Could be an overboost issue. If you could get your hands on another n75, might be worth a try...

[gmaster]

Thats just it its not throwing any codes or lights up just splutters sometimes i run it on super unleaded just to be safe to just dont understand why its only sometimes

You should always run it on super unleaded, are you using v-power? What was the map set up for 97/99ron ?

[briso 101]

Have you tried umplugging the MAF and running it ???

Shot in the dark tbh.

Dont mean to sound stupid but probably will but i have no idead what you mean by unplugging the MAF or someone else talking about the N75 valve or something i am not that good with cars like that .

[jmf]

Check out the attached pic. The yellow circle shows the maf connection. To disconnect it just press on it and pull. The ESP light will come on, but don't worry about it (it should go away once you plug it back in, worst case you have to clear it with vag-com).

[KenONeill]

Check out the attached pic. The yellow circle shows the maf connection. To disconnect it just press on it and pull. The ESP light will come on, but don't worry about it (it should go away once you plug it back in, worst case you have to clear it with vag-com).

Further to this, when you unplug the MAF, take the car for a run, and see if it runs better than it did.

If it does, then the MAF is faulty and should be replaced. The reason for this is that disconecting the MAF causes the engine to use a set of default settings rather than the MAF readings.

[briso 101]

Further to this, when you unplug the MAF, take the car for a run, and see if it runs better than it did.

If it does, then the MAF is faulty and should be replaced. The reason for this is that disconecting the MAF causes the engine to use a set of default settings rather than the MAF readings.

thanks for that i shall be trying that .

[kpap]

Check also your blow-off valve , many starts failing after remapping because the increased boost pressure. You will have boost problems like you describe if it starts to fail.

[briso 101]

Have you tried umplugging the MAF and running it ???

Shot in the dark tbh.

Ive unplugged it and it is running better so looks like the fault just hae to find another 1 now thanks.

[moose52c]

Hey I had a problem like that a few weeks back. no great power at 1500/2500revs. it turned out to be a Ht lead easy fix!

[Jonny 0101]

Took my vRS back to the dealer yesterday to get mechanics to look at it. Sod's law being what it is, the car was running really well with an audible whistle on boost and enough urge to put a smile on my face. Still wanted it looked at, as this wasn't likely to last. Mechanics spent some hours over it and resulted in a new MAF sensor and cleaned throttle body. The drive home was whistle-free, which concerned me, but the car felt different and sounded it too. Wasn't convinced that this had really made much difference, until I drove it back from the gym tonight. Floored it in second and I swear I popped a wheelie, it had that much urge! No sign of a whistling turbo still (not sure if that is good or not), but hopefully performance will remain consistent now. Hope this works for you too, good luck.

[chrisjackson]

Hi guys just wondering if any can give me some advice please.

I had my car remapped in november it was all running good but now ive noticed that sometimes the car will not boost u put urfoot down and u can feel it trying to boost but holding back the boosting the holding back this is starting to happen alot now.

Sometimes if i switch thecar off andstart it again the problem goes but sometimes it takes a few off and on.

Could this be a problem with the remap do you think as if it is i can ring the and tell them to come sort it out.

many thanks guys.

how long did the car run ok for?

if it ran ok for a good period of time then it cant be the map! map is just a computer file and doesnt change. if this has happened over time then its a car issue

[dirty hari]

could be loads of things N75, DV, Coilpack, poss split hose get it vagcommed

you can check for split hoses yourself and the DV is easy enough to check if you remove it. Look on the forge website theres plenty of PDFs.

good luck