hi, i am a new member here

my 94Z wont start, but here is what i have done so far:
1. got spark[/align]2. checked pressure of fuel rail: was 50 psi but dropped to 30 psi after the first 2 seconds of the key being on, then steadily fell after that[/align]3. checked lines and injectors for leaks, did not see any. gas cap tight.[/align]4. replaced fuel filter - the gas was clean coming out of the old filter[/align][/align]i read the sticky about testing fuel pressure already but i would like some more information[/align][/align]i asked some friends at school and they think it could be the fuel pressure regulator[/align]they mention blocking off the return line and i would like to know how to do that[/align]

 

I am going to go out on a limb here...

You got a bad pump.

Get R Done



Regulator could be bad but most times the pump is shot. Pressure and return lines are easy to access right on top of the intake.

 

Fuel pressure should only drop if the engine is running as the regulator needs a vacuum source in order tocontrol the fuel pressure. You may have a bad pump,bad regulator, leaky injector, or plain old fuel leak.

 

Thanks for the good suggestions

im at school during the week but i will be home on the weekends to work on the car
i'll keep u posted

 

so i put the fuel pump in this weekend and still the car wont start
next weekend im going to check the regulator

 

You sure you installed the pump right? What did you do with the pump enclosure?

 

i'm sure i installed the pump right, it still cranks and cranks like it did with the old pump
im not sure what u mean by the pump enclosure

 

Just a little pre-screening question on the pump enclosure. Not important.

Anyway, you say you got spark so let’s do this.

Go to the store and buy some Gum-Out carb & choke cleaner. Have a friend over and ask him to get into the car and hold the gas pedal down to the floor and crank the engine. Stand in front of the car with the hood open and the rubber t-body snorkel removed and while he is cranking the engine with his foot to the floor spray the carb cleaner inside the t-body.

Does it start? If there is a fuel problem it should start but then die quickly because the Mass Air snorkel is not connected.

Be sure you have it in park, out of gear and the e-brake on so you don’t get run over I know it is common since stuff but we could get some ignorant MB owner in here.

 

tested pressure on fuel rail.[/align]energized system by turning key on [but not cranking][/align]gauge went to 51, then dropped slowly to 49 and held there[/align][/align]removed, cleaned allcrud and bolted down all negative and positive wires between battery and motor and fender well[/align][/align]clampedhose connectionto prevent leaksbetween vac booster on power brake master cylinder and intake[/align][/align]removed, cleaned and reattached all spark plug wires where they go into the optispark[/align][/align]sprayed carb cleaner down throttle body with foot to floor[/align][/align]still no start [car makes infrequent sputter][/align][/align]so... whats next?[/align]

 

Make sure the two FI fuses are good. Invest $20 in a set of NOID lites andsee if the injectors are being fired.

Time to check ignition system (should have been the first thing)
1) replace your spark plugs and wires. The plugs are most likely fuel fouled by now anyway.
2) Inspect and clean all the low voltage wiring between PCM, Opti, Coil, Ignition module. Get some contact cleaner from Radio Shack
3) Try new ignition coil
4) Try a new ignition module
5) Time for a new Opti
Keep in mind that the Opti serves a bunch of function including sending timing signals back to the PCM, without which, the FI won't work.