Tonymi

Hello everyone my 996 won’t start was run great at the 2 days ago after park the car in the garage 30sec after it’s just shuts itself off and now it will crank but won’t start. Any ideas

pdxmotorhead

First step is hook up a monitor and see the codes..

Most likely first things,
1. Fuel Pump or Fuel Pump relay
2. Spark (Check fuses and relays)
3. Sensors Crank/Cam

808Bill

Out of gas?

DBJoe996

CPS=crank position sensor
Most common cause of "cranks but won't start"
Other common cause=fuel or fuel pump
Have to check fuel pressure at the rail
Then you have to start on all the other stuff...fuses, relays, checking for spark, ignition switch......

Mike Murphy

If you have a helper, you can try spraying starting fluid into the air intake while someone else is starting it. If it starts to fire up and then dies, the fuel is not getting there, but you have spark and compression.

Phiphe

First thing to do before anything is make sure the carpet or mat hasn't slid up under the clutch pedal prohibiting the little sensor on it from being fully depressed. If the sensor is being stopped from full depression the motor won't crank. GL

808Bill

He said it cranks but won't start, so that's not it.

Phiphe

My mistake, sorry.

5CHN3LL

If it's NOT a C4 (i.e. the gauge is actually reflective of how much fuel is in the tank, and it shows fuel), I'd suspect the fuel pump, pump electrics (relay), or a clog in the fuel system.

808Bill

This and CPS's have been dropping like flies these past few months.

Tonymi

So now the CPS it’s broken in side the block

808Bill

Edit: I's a lot tighter than I remembered.

Bummer. Always pre treat these old cars with BP plaster or similar before trying to remove. Been there done that!
Now you need to center punch and drill it out. It's not that bad, just time consuming... I would blast every nut and bolt while you're there.

Tonymi

Hey everybody a little update

i replace the CPS still doesn’t start

I also replace the fuel pump and fuel pump relay and it still doesn’t start

i checked all the fuses and there are all good everything else (electric) works great

I sprayed carb cleaner to the throttle body and the car start and works perfect for 2-3 seconds and then shuts off again

Prelude Guy

That means you have compression, air, and spark, but not fuel.

You need to focus on the fuel system.

Can you hear the fuel pump prime?

Tonymi

I’m not sure. I definitely hear something when open switch but not sure if it is the pump