Hey all,

 

I've had a few issues around the VRS for a while now but only had the time to investigate them.

 

So both the performance of the car and the brakes have been sporadic, where sometimes the car will pull amazingly and other times, not so much. Likewise, most of the time the brakes are pants and the odd time, they are amazing.

 

Some of the symptoms I'm facing are:

• First cold start of the day is longer, lumpy and kicks out a puff of smoke.
• MPG has dropped to 39, although this could be related to the weather?
• Turbo sometimes feels like it's only kicking in at 2500 (although you can hear it lower down most of the time.)
• Brakes are pants most of the time.

Not sure if this is related to the ASZ, but I had similar issues in my Bora if that helps?

 

Today I logged a few runs on channels 10/11 and although the car pulls nicely, I think there is still something wrong.

 

What is a major concern though are my brakes.

• When parked on a hill, the next morning the brake pedal is solid.
• When driving normally, the brake pedal is soft and travels quite a bit.
• After harsh acceleration (more noticeable after doing the 10/11 runs) the brakes are amazing.
• On a few occasions the brakes have went solid but struggled to slow the car down.

I've attached my logs and graphs. Anyone suggest what could be wrong or what to look for?

 

I can't see any splits so far in any of my pipe work and my vacuum box makes a noise when the engine is running but not after switching the engine off.

 

Cheers

LOG-01-010-xxx-xxx.CSV

LOG-01-011-xxx-xxx.CSV

Just to add more info this this.

 

Went out again whilst the engine is running, pumped the brakes. The pedal gets harder until I leave it for a few seconds and then it goes back to being soft. 

 

I've noticed if I hold the pedal the engine drops about 100 rpm.

 

Looking around there is apparently an output test for the vacuum pump however when I try and connect to the controller in VCDS Lite, I get no response from the controller :( 

With the engine off, keep pumping the brake, it should go hard and stay hard for a while.

Keep pressure on the pedal and start the car, it should drop down.

Your just up the road from me so will keep an eye on this if you ever need a hand

I would say that you definitely have a primary vacuum problem, something is leaking badly or not working properly.

Yeah, definitely goes rock solid and drops when starting the car.

Hutchy, where abouts are you mate?

I would say that you definitely have a primary vacuum problem, something is leaking badly or not working properly.

I don't have any errors or anything coming up vcds though. When doing an output test on channel 11, you can see its holding vacuum.

Any suggestions on where to look? I don't have a compressor or any sort to pressure test the system unfortunately :(

I don't have any errors or anything coming up vcds though. When doing an output test on channel 11, you can see its holding vacuum.

Any suggestions on where to look? I don't have a compressor or any sort to pressure test the system unfortunately :(

 

You won't necessarily get any errors on VCDS, all the symptoms you describe point to leak somewhere, check the output barb from the vacuum side of the tandem pump, these have been known to leak, then work your way through all the pipework disconnecting and testing, just 'looking' and staring at VCDS isn't going to cut it, you need to get your hands dirty.

You won't necessarily get any errors on VCDS, all the symptoms you describe point to leak somewhere, check the output barb from the vacuum side of the tandem pump, these have been known to leak, then work your way through all the pipework disconnecting and testing, just 'looking' and staring at VCDS isn't going to cut it, you need to get your hands dirty.

Will check them tomorrow if I can, however is there any images of the hoses/pipes to check as there are tonnes.

Yeah, definitely goes rock solid and drops when starting the car.

Hutchy, where abouts are you mate?

Just down beside chapel house way.

Will check them tomorrow if I can, however is there any images of the hoses/pipes to check as there are tonnes.

 

Yes it's work, nasty.

Just down beside chapel house way.

Good stuff mate. Will definitely look at taking you up on that.

Once this issue is over, I've got plenty more on the to do list lol.

Out of interest, noticed on your build thread that you had done your timing belt. Is this somebody you're comfortable doing for others?