96 Passat TDI wont shutoff on first try

I am a glutton for punishment...so when I found a 96 (perfect match to my 97!)with 149k on it for CHEEEEEEP, I had to do it! The problem I have right now is that the engine will not shut off when i turn the key off, but if i turn it back on/off quick then the engine shuts off. I do have a lit CEL, but the OBDII scanner will not communicate with the vehicle. Will a VAGCOM read the CEL when and OBDII cant?

I replaced the ignition switch and the vaccuum line inside and outside the ecu today and still have the same problem. My glow plug light also flashes intermittently and the engine idles a little high (1100-1200 rpm). I also have an intermittent bubbling of air coming from the fuel filter into the line between the filter and the pump.

The car is also a little light power, but I can hear the turbo spooling. (maybe N75?)

I know there are a myriad of issues/possible fixes for these issues....where do I start?

Thanks!

Check N109...it may need to be replaced, or there's an electrical issue between the ignition switch and N109.

This thread is a good read.

The "Car won't start troubleshooting thread" also has some pertinent information

Tony

Tony, it runs fine, he just can't get it to shut off.

Maroon, have fun with that and let us know what you find.

96's were not OBDII, you can only read codes with VCDS / VAGCOM

Windex said:

96's were not OBDII, you can only read codes with VCDS / VAGCOM

Click to expand...

'96 with the original black ECU having the "BK" suffix are not OBDII.
'96 with the 'smoke fix' performed will have a silver colored cast metal ECU with a "GQ" suffix and those are OBDII compliant.

The B4 have a known issue of the contacts in the ignition switch wearing out, but I think your problem is a sloppy engagement of the key lock into the switch contact in which turning the key to the stop does not translate into the contact section turning just as far thus remaining with the contact barely in the 'run' position when the key is in the 'off' position.
Try pressing the key in deeper when it's in the 'off' position to see if that shuts the electricals off. If it does that enhances my theory of play between the lock half and the electrical half.

Thanks for the info lug nut! I will try pushing in the key next time i go to turn the car off.

I have the cast metal ecu, but the newer OBDII scanner at oreilly wont read the codes. I am using a buddies VAGCOM on wednesday, so we will see if that works better.

BUT!!!!, since i replaced the vacuum lines to/from the N75 and the brake switch, the glow plug and cel lights are off! I took it for a 30mi round trip just to check, and they didn't come back......hopefully that has done the trick.

I had a wire from the ecu to the fuel shutoff solenoid that had worn through the insulation and was shorting out, so the fuel shutoff solenoid would not shut off the fuel....check the wire from it back to your ecu and make sure there is continuity. Otherwise as usual Lugnut should have your cure.

The fuel shut off solenoid is powered to open and permit fuel flow.
You'd have to have a short to a hot lead, not a ground point, to keep the solenoid valve open.