129CBRider

I would just like to add to this something that I learned when my 2001 TT Quattro 225 started to stall out at the first stop sign I came to after it warmed up and wouldn't start again until it cooled.

The Crank Position Sensor also controls the fuel pump after the engine is running. When you open the driver's side door or turn the ignition key, they fuel pump pressurizes the fuel rail but it is the Crank Position Sensor that keeps the fuel pump running after start up.

I imagine this is to keep the pump from pumping out the whole gas tank if a fuel line breaks and the engine dies but the key is left on. Like in a wreck...

Ralph Flores

on the bracket, their are two other connectors, does anyone know what they are, mine are cracked, busted and I need to remove and replace?

vg8s

finally tackled my crank sensor on my mk1 TT 180 FWD. i had to remove my oil filter to get better access. i think the previous owner did not have the screw to hold the sensor in place. i just pulled the sensor out. now i have the new sensor in and need to get the 5mm bolt to secure it to the block. i was able to get the car started and it did get rid of a P0327 engine code i was trying to diagnose as a bad knock sensor. Now i need to see about getting the part number to the 5mm bolt to properly secure it. Thanks for all the great pics you posted.

vg8s

Update:
after putting the crank sensor in, started the car, drove it home 30 miles on a Friday afternoon and parked the TT in my garage. Time for me to go to work on Monday morning, so i got in my car, started it up and drove the car in to work with no issues and parked it in my usual area. Went back out to my car for lunch and the TT would not start. Same symptoms...turn the key and it just cranks and cranks. WTH could it be!!!! About to have the vehicle towed to my buddy's shop about 20 miles away. Any other advice would be helpful right now.

Thanks,

Jaime

129CBRider

When I changed my Crank Position Sensor last year after it made the engine die after it warmed up, I found metal filings stuck to it's tip which is magnetic.

The sensor is apparently a magnetic switch and the tip of it can act like those magnetic drain plugs that are supposed to collect metal bits out of the oil.

I think that maybe even a new CPS will not perform properly if metal bits are stuck to it.

I also replaced the Cam Position Sensor at the same time although it is rare they go bad.

The computer uses the Cam Position Sensor to determine the Crank Position until the starter gets the engine turning over faster than 64 rpm's I read somewhere.

Also if your battery or alternator is bad or going bad and your voltage is under 11 volts, it will keep the car from starting properly.