Every other startup dies

[240sxinlv]

So my friend brings me his dads car and wants to fix it for him while he is out of town. His dad has been putting off the fix for a year now.

Heres what it does, any condition cold or hot, every other time (or so) you start it. There is no way to keep it running if the car doesnt want to.

Turn key, revs up to 1000, drops to 0, dies, turn key, revs up to 1000, down to 750, runs great.

1986 Z31 Turbo 150,000 miles ALL stock.
Modified by 240sxinlv at 6:48 PM 8/13/2006

[evildky]

first things that come to mind would be the CHTS and the FICV

[240sxinlv]

Well I narrowed it down a bit. Something is turning of the injectors right after turning the key. I also have codes 14 Speed Sensor and 24 Neutral Switch.

According to the FSM it looks like fuel is cut if the car is over 137mph. If the Speed sensor was acting up maybe the car isnt sure how fast its going and shuts down? The speedo needle does bounce around a bit.

As far as the neutral switch, if the car thought it was in gear while cranking would it cut fuel?

Its a 5-speed btw.

[240sxinlv]

Well, I hooked up a inline fule pressure gauge. I dont know if the gauge was very good but it was a good test.

The times it started up and ran normal the pressure was at 40psi. The times it would start to die out it would slowly loose pressure over about 20 seconds and sputter out around 5psi.

I'm gonna replace the pump and see what happens.

[evildky]

are you sure it's not a bad fuel pump? also the mas sends a signal to the ecu needed for the fuel pump don't know if it would come into play in your case

[240sxinlv]

Fuel Pump Relay.

Located behind the passenger side panel near the seat belt.

Replaced the relay, still didnt work.

Spliced the two black wires going to the relay, works.

Pump runs with key on.

[evildky]

so the signal is interupted before it gets to the relay, you investigate your speed sensor any more?