12 replies to this topic

[tk1]

Hi all,

 

I have a nearly standard VX220 turbo with only a modified exhaust which includes a sports cat. Had it on for a while and not had any issues with it even though it is a little thirsty but I can't determine if that is my driving style or something to do with the exhaust.

 

About 6 months ago it developed something where it would spool up the turbo and you would feel it begin to boost ever so slightly at 3/4000rpm but then it would feel strangled and not boost any further - like completely flat. However if you dip the clutch and rev it, it would rev through the rev range like normal. I kind of left the car for a few weeks to go on holiday, then when I came back it was fine.

 

In its current form though, its still not boosting right. It is normal on power in first, second and third but come to fourth and it just has a really messed up torque curve. Its distinctive enough that anyone would notice it who drove the car and it just feels really slow. Even in all the gears it feels like it struggles and just doesn't want to rev and always down on power.

 

The car has no engine management lights show up. I've changed the mass air flow sensor which doesn't do anything although because the ecu has reset it kind of feels quicker for a bit and then dwindles back to being dodgy. I just remember the car to be savagely quick and it hasn't been like that for a while. 

 

 

Can anyone suggest where next to start looking? I worry that its just going to become one of these things where I spend a lot of money changing things and trying to identify the problem and it still doesn't fix the problem. Not sure if I trust anyone local too - I'm based up North just past Durham.

 

Thanks 

[Duncan VXR]

Oem intake getting hot and collapsing? DG

[Bumblebee]

Try not to get to disheartened as no doubt it will be something simple as Duncan says like the intake pipe collapsing, it's worth getting an alloy replacement if this is the case

[Nev]

As above, if you have the OEM rubber pipe that feeds air from the airbox to the turbo then this is a possible candidate. The pipe ages over time and when heated by the exhaust can get soft and collapse, thus strangling air getting into the turbo. Replace with an item sold by Pro-Alloy or make your own.

Edited by Nev, 25 January 2014 - 08:26 AM.

[Cookies220]

Does the engine run rough at all?  I had a boost problem which turned out to be due to a knackered throttle pedal assembly.  Best thing to do would be to meet up with another friendly vx 'er who you cold swap parts out with to try to find the fault without having to buy loads of new bits.

[tk1]

Is there anyway of seeing if this pipe has collapsed at all before or does it just 'uncollapse' when not under boost? Think it's worth replacing anyway.

 

 

Does the engine run rough at all?  I had a boost problem which turned out to be due to a knackered throttle pedal assembly.  Best thing to do would be to meet up with another friendly vx 'er who you cold swap parts out with to try to find the fault without having to buy loads of new bits.

 

When you say the engine running rough, do you mean at idle or even when running. It tends to idle a little bit rough but I always put that down to the exhaust. It might hover around 300-500rpm sometimes. 

 

Thanks for the help everybody.

[Ormes]

Rough idle couldn't be put down to pipe collapsing, though the in gear boost does sound like the pipe.  Plugs or coil pack for rough idle?... do you leave it in the rain?

[Rickwoo118]

Is there anyway of seeing if this pipe has collapsed at all before or does it just 'uncollapse' when not under boost? Think it's worth replacing anyway.    

Does the engine run rough at all?  I had a boost problem which turned out to be due to a knackered throttle pedal assembly.  Best thing to do would be to meet up with another friendly vx 'er who you cold swap parts out with to try to find the fault without having to buy loads of new bits.

  When you say the engine running rough, do you mean at idle or even when running. It tends to idle a little bit rough but I always put that down to the exhaust. It might hover around 300-500rpm sometimes.    Thanks for the help everybody.

300-500rpm doesn't sound right. Have you plugged in a tester to see if you have any error codes?

[mbes2]

Test the car with the MAF disconnected, the map will default.

 

Do you have a boost gauge for testing PSI ?

[siztenboots]

rough idle means you have a vacuum leak

[Duncan VXR]

rough idle means you have a vacuum leak

 

Yep check vac storage box under inlet manifold as those little boots like to come off. Any other vac pipe work

 

As stated other things that may be adding to the issue is AMM and plugs / coil packs

 

Do find coil pack / plugs tend to be more misfire under load

 

Beyond this could be poor earth issue / connector of dooooooooooommmm

 

DG

[siztenboots]

the carbon canister solenoid could also be venting into the intake vacuum. Its just a matter of pull off vacuum hoses from the intake , and plug the hole to isolate the source, then eliminate section of the pipework feeding off that.

[Mcollings]

Did you ever fix this? I'm having the same problem, based Carlisle

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