996 turbo will not start

[PeteMcK]

Hello !! I have a mystery I need help with. My car is a 2001 996 Turbo manual.

I drove my car for 30 minutes, parked it and went on an appointment. Returned an hour later and...it would not start and ended up with a tow truck recovery. Well, having followed all the good advise on reasons and cures for non starting - my car still wont start !! New fuel pump relay, new fuel pump, new battery and new fuses. There is over half a tank of fuel and plenty of battery power. Itturns over really well but it will not fire !! Any other thoughts or potential reasons that I may have overlooked ??

best wishes

Pete

[wross996TT]

Make sure the clutch is fully depressed....or perhaps the clutch switch is broken.

[1schoir]

+1

Try bypassing the clutch interlock switch by installing a temporary jumper wire at the switch. You will find the switch directly behind the metal arm of the clutch pedal.

Regards, Maurice.

[Dus10R]

Have you scanned it for codes to make sure the ECU is still working?

Also check to see if the throttle body (TB) is operating, turn the key on and let it sit, go back by the engine bay and you should hear a whine and a few ticks as the throttle body runs through a cycle and does a reset, usually takes a minute for it to start after you turn the key on. If you dont hear this, the TB may be bad and could be fully closed not allowing enough air in for the car to start.

You did fuel pump, did you change the fuel filter?

Plus the clutch switch as mentioned already.

[SSST]

If it was the clutch switch it wouldn't turn over.Good luck.

Edited December 15, 2012 by SSST

[Duram]

If you feel under the drivers seat do you feel any moisture? Sounds to me that it could be an immobilizer issue. If you have a way to check for fault codes with a tool that can read factory codes, you may have see an immobilizer fault in the DME. This would mean that it is not communicating with the Alarm module. Other possible immobilizer faults may be stored in the Alarm module. One quick check you can make with any scan tool is to see if you can connect to the engine module. You can do this even with an OBD2 tool. While the OBD2 tool will not tell you the immobilizer faults, nor will it read the alarm module. But if you can connect via these tools it will tell you that the K-Line connection between the alarm module and the DME is working. If you are unable to connect, then this would show that there could be a problem with the Alarm box. The communications used by all scan tools to the engine is routed from the OBD2 port first to the Alarm module then from the Alarm module to the DME. This same wire that is used for diagnostic tools is also used by immobilizer system to exchange codes prior to authorizing startup.

[PeteMcK]

Thanx for all the help and apologies for the delay in replying - mad time of year.

Problem sorted - it was the fuel pump but also a faulty new relay, so put "old" one back and it fired up. Car currently with PARR for extensive changes and will post after completion sometime in late January.

best wishes

PeteMcK