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Discussion Starter · #1 · (Edited)
Hi

Vehicle : Passat year 2000 18 turbo - Manual

When changing gears and depressing the clutch pedal, the revs continue to rise even though the accelerator is released. Has anyone had the same fault?

I did read somewhere that on the "FBW" (Fly by wire accelarators) versions if you reved to 2000 RPM and dipped the clutch (In Neutral) the revs would return to idle, Is this correct? and if so that would mean that there is a switch on the clutch pedal sensing this. Mine however does not do this, could mine have a problem then with this? Could this also be causing the above as well?

Rgds Richie
 

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I havent had this issue on my car but I'll take a guess that the throttle body needs cleaned. Could be dirty causing it to stick slightly open. I had this problem on another vehicle I own and that took care of it.
 

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Lisa Simpson
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It's an emissions thing, as I understand it. The other issue is our six-ton flywheels, which have a spin-down time of next to eternity. Are you seeing the car sit at 2K for minutes, or for a couple of seconds? A couple of seconds is not totally abnormal.

A throttle body cleaning is never a bad idea. :)
 

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atomicalex said:
It's an emissions thing, as I understand it. The other issue is our six-ton flywheels, which have a spin-down time of next to eternity. Are you seeing the car sit at 2K for minutes, or for a couple of seconds? A couple of seconds is not totally abnormal.

A throttle body cleaning is never a bad idea. :)
These are the first cars I've seen where they stick a 3 inch thick flywheel on a little 1.8t motor.
 

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Discussion Starter · #7 ·
Thanks guys.. i will try following:

1. Throttle body adaptation
2. Throttle body cleaning
3. Check the emissions

But what about the switch on the clutch pedal (Clutch sensor), can someone try the following for me and tell me if what i was told was true.... rev your car to about 2000 RPM (keep it constant) in neutral and then put your foot on the clutch, I was told that the revs would drop.

Rgds Richard
 

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Discussion Starter · #9 · (Edited)
My Mistake.... its the brake not the clutch

This came from a guy on Ebay selling a cruise control (Retrofit Unit).

Link http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=4593157197&rd=1&sspagename=STRK:MEWA:IT&rd=1

On the link you will note he says the following :

1. "Suit any VW - AUDI - SKODA - SEAT with 'Drive By Wire' throttles."

2. "To check your vehicle has 'Drive By Wire' or 'DBW', Sit with the vehicle in Neutral, Rev it upto 2,000RPM & at the same time put your foot on the brake pedal.The rev's should drop back to idle.Please note: This System will not work with a cabled throttle."

I was initially wanting to add cruise control to my Passat.

Rgds Richard
 

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taylor_rich said:
Thanks guys.. i will try following:

1. Throttle body adaptation
2. Throttle body cleaning
3. Check the emissions

But what about the switch on the clutch pedal (Clutch sensor), can someone try the following for me and tell me if what i was told was true.... rev your car to about 2000 RPM (keep it constant) in neutral and then put your foot on the clutch, I was told that the revs would drop.

Rgds Richard
try #1, and then check the CPP switches. There are two: one for the starter interlock, and one to tell the ECU the clutch is pressed and to let the revs fall. You'll need a vagcom or a multimeter to check it out.

If the ECU doesn't see the clutch depressed when the throttle is lifted, it will not let the revs fall as quickly...this reduces emissions of unburned fuel.

With a constant foot on the gas, pressing the clutch in/out doesn't matter.

Supposedly pressing the brake and the gas at the same time will cause revs to drop.
 

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atomicalex said:
Yes, it should. This is to prevent "powerbraking". However, the easiest way to determine if you have DBW or a cable throttle is to open the bonnet and look for a throttle cable!
Or just look at his first post and see that its a 2000. 1998-1999 were the only ones that were DBC
 

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Discussion Starter · #13 ·
Thanks for all the replies

I do have a registered version of VAG-COM - How would I use this to see if the Clutch sensor is working? Is there a function to in VAG-COM to test the IO's?

Rgds Richard
 

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Discussion Starter · #14 ·
I do know this car is a FBW version.... that was not a question, the question was whether my clutch sensor was working

Rgds Richard
 

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Discussion Starter · #17 ·
Hi

I have checked Measuring block 066 field 2 and both the clutch and brake pedals sensors are working. I do have a question here though... how far should the clutch be depressed before the switch activates? I barely touched the clutch pedal and the switch closed.

Also... when applying brakes when holding the revs at a constant 2000 RPM had no effect on the revs.

so... tomorrow I will try the throttle body adaptaption.

Rgds Richard
 

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taylor_rich said:
Hi

I have checked Measuring block 066 field 2 and both the clutch and brake pedals sensors are working. I do have a question here though... how far should the clutch be depressed before the switch activates? I barely touched the clutch pedal and the switch closed.

Also... when applying brakes when holding the revs at a constant 2000 RPM had no effect on the revs.

so... tomorrow I will try the throttle body adaptaption.

Rgds Richard
your CPP operation sounds perfect, the CPP requires just a slight touch. the starter interlock requires ~pedal to the floor.
 
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