Slow turbo response

[FarmerPug]

A bit of a problem ive noticed over the last couple of days is the boost isnt kicking in at the right moment, its most noticeable in 3rd and 4th gears where the car needs to rev past 3000rpm before it takes off, normally the turbo kicks in just before it hits 2000rpm, thus its a bit laggy at the moment, yet at times in some gears even 3rd and 4th it can still boost at the right time.

I plugged the pp2000 in and found nothing significant, and nothing that came back after clearing them:


Any reasons for this issue, could there be a vacuum leak somewhere (if so where and whats the best way to detect it), the oil is changed regularly, the car smokes if you floor it but its good honest black diesel smoke not blue smoke, egr cleaner is used every year, all the oils, and filters were done not long ago, and up until a couple of days ago it wasnt really a problem.

[grasmere59]

I know it might sound daft but when I first had my car it was sluggish and the cruise didn't work.I found the clutch switch had fallen off the back of the pedal bracket,i see you have a clutch switch fault?

[Welly]

Could be the Vacuum side of things, be worth checking the solenoids and the Vac lines first. A lad on here ages ago replaced the Vac pump on the end of the Cam Cover and found it cured performance problems but it doesn't seem 'common' on here really.

Don't be thinking the Turbo is at fault, these are very reliable. It would also be worth checking all the 'plumbing' to and from the Turbo checking all the large hoses are tight etc. first.

[mjb]

Just to clarify: have you definitely encountered your problem after the faults have been cleared, without them re-appearing?

It's been reported before that the pedal switches can sometimes affect performance - the car being unwilling to let the turbo spool up if the clutch is disengaged and/or the brake is pressed.

[FarmerPug]

The clutch/brake pedal fault probably came up from the time i added the run lock i unplugged the clutch switch and this was probably still in the memory, but just to be sure what is the paramater check on pp2000 is it to see that both are off when neither pedal is pressed?

I checked and cleared the faults last night, drove the car this morning and it seemed fine, but this evening when i got home from work it did it again, its in 3rd and 4th sometimes when you plant the foot it takes a bit of time before the turbo kicks in, and this can be a bit of an issue when overtaking. 1st and 2nd seem fine.

About the vacuum side of things, how can i identify a leak, would spraying water or wd40 round the pipes and listening for any funny noises work, or would a proper vacuum leak detector which puts smoke out any leaks be required

Also what are the chances the MAF sensor needs to be cleaned, ive used EGR cleaner 3 years in a row, and normally it gets sprayed in when the air filter is removed thus straight over the sensor, perhaps the EGR cleaner isn't good for the sensor?

[FarmerPug]

Just drove the car with the MAF sensor unplugged, it appears to be going much better, turbo is boosting at about 1700rpm in every gear ill leave it out a few days just to confirm its the sensor and then give it a clean

[Doggy]

I have a similar issue. Tried disconnecting the MAF - definitely made it worse. Cleaned it, (made no difference).
Took up the slack in the throttle cable as previously sugggested - gave an initial impression of improving response, but all it really does on mime is give the same behaviour on a smaller throttle opening.

Resorted to apathy / awaiting inspiration.

Good kuck with yours Frank, please let us know how you get on.

[FarmerPug]

Does the 2.2 not use the maf sensor differently than the 2.0, even this morining with the maf still disconnected the car drove great

A while ago the throttle cable was an issue the time i changed the timing belt i think i knocked off the retaining clip and the cable went slack thus making the car feel slow, also the odd time the floor mat can get caught up behind the throttle and do the same thing

[rwb]

Any more thoughts on vacuum?

I've been comparing diagrams in Service Box, and I see that the 110 has an extra vacuum control valve (compared to the 90) that goes to the turbo.

There's also the air doser -- which seems to be very different on the 2.0s to the 2.2. It's located just before the inlet manifold. I have no idea what it does, but it's position implies restricting air flow or dumping pressure, which could be related.

[Doggy]

On the 2.2, it's used to select between the normal intercooler and the water-heated exchanger used to aid warm up and raise inlet air temp during dpf regens. No idea what it does on the 110.

[grasmere59]

Not all 110's have the air doser,my 52 plate Rapier used to have one but my 53 plate 110 doesn't.

[FarmerPug]

what does the air doser do?

[Captain Jack]

TPS?

[FarmerPug]

Throttle position sensor is ok, i took the car up the motorway still with the MAF sensor off it pulled strong in all gears the problem is gone, but i assume the sensor will need to be cleaned or replaced before plugging it back in.

[madmadmax]

the clutch and brake switch is the cause of the lag as the ecu thinks you have the clutch and brake peddle pressed down so it's putting less fuel in because it thinks you are slowing down all the time