Lost horses.... If found please return.

[Paul Smith]

Hi

I have a 2007 2.0 170 FR that must be missing it's horses. I think the gate must have been left open or something, as anything under about 80mph leaves me behind and I'm talking 1.2 corsas etc so nothing exciting.
I have done the Mr muscle clean, changed the n75 valve, changed the boost pressure sensor and repaired the connections to the electronic actuator.
I have moments of power where I'm quite impressed but only about 10% of the time but no power 90% of the time.
I'm on the edge of replacing the turbo but holding back because of the 10% of time I have power saying the turbo works. I've checked the pipes and can't see anything obvious.

Any help or ideas

 

[R3k1355]

Does it have an electronic actuator like the CR 170??

If so there's a setup procedure for that.

 

[Paul Smith]

It's definitely electronic

 

[Rusty2k]

The vane actuator is vacuum operated. The electronic component of it is a position sensor. (Same goes for the CR engine.)

It can be tested with a hand vacuum pump / tester or if you have diagnostic equipment such as VCDS then there's a test procedure that can be run that will attempt to fully extend / retract the actuator with the engine at idle.

I believe the actuator on the Garret turbo on the PD engine works the opposite way from the Borg Warner actuator on the CR engine. The Borg Warner one extends the piston when vacuum is applied and I believe the Garret one retracts the piston under vacuum.

To be honest I've never been a fan of the replace and hope approach of solving problems. You usually end up replacing a lot of stuff that's not needed and you could have put that money into some test & diagnostic tools instead. A hand vacuum tester is a great tool to have for these engines with all the vacuum actuated stuff they have.

 

[Paul Smith]

Ok so I have pumped it up to 2 bar but the actuator arm didn't move? Although was holding the pressure?

 

[R3k1355]

2 bar vac?

 

[Paul Smith]

Nope misread it and missed the vacuum bit (lol). Luckily no harm done, I'll lay my hands on a vacuum pump from somewhere and report back.

 

[Paul Smith]

Used a vacuum pump to which the actuator was drawn in and held until I disconnected

 

[Paul Smith]

On a side note. I have unplugged the air sensor and the car yes is still sluggish but I'm sure it's boosting. Definitely an improvement when unplugged. Strange though as I'm plugged in and no codes or errors saying it's unplugged?

 

[Paul Smith]

Driven for 32 miles this morning without the maf plugged in and about 25 miles of a driveable car which was nice. Had a lack of boost mid journey but seemed to clear again.

 

[R3k1355]

Maybe get a new MAF and see what that does, very strange it's not thrown up an error code though?

 

[Paul Smith]

Ordered the new maf. On the way home it was better but stopped boosting in higher gears so feel that identifying a problem with the maf was good but don't think it's going to be the entire problem

 

[Paul Smith]

What I might try is the Mr muscle again but using the vacuum pump to hold the actuator open what do you think?

 

[R3k1355]

Yes if the actuator controls the VNT movement then moving it around while cleaning it might help free the nozzles up.

 

[Paul Smith]

I guess whilst i wait for the maf then doing this can't hurt.

 

[shontzy]

I had a similar issue with my Cupra. I thought it was MAF related at first and unplugging helped and replacing did nothing. After looking for a vacuum leak and a variety of other places for my inconsistent power, I got a code that pointed me to the MAP sensor. I pulled it out and cleaned it and it has been great since then. Its a free check so I suggest doing a cleaning.

 

[Paul Smith]

Hi I've changed the map sensor for a new one but no difference.

 

[Paul Smith]

Looking online and need some clarity. I have a new map sensor and have used it to replace the sensor on the pipe on the front left side of the engine. However I keep reading about a map sensor on the inlet manifold. Is there 2?

 

[Paul Smith]

Ok found today that the air pipe connecting straight to the bottom of the turbo wasn't fully connected and the green rubber seal has broken up and come off. After reconnecting found still flat spots but some fast boost. So in the right direction I hope.

 

[R3k1355]

Maybe there are further loose or damaged hoses??

Did you give it a second round on the Mr Muscle already?