scope513

Ok, so I tested to see if spark was coming from coil...nothing. While cranking I noticed I didnt hear fuel pump. Checked again to make sure...no buzzing sound. Fuel pump is brand new, will a bad icm make the ecm not make fuel pump work?

scope513

So?

Injuneer

There are several codes that shut down the fuel system. The PCM controls the fuel pump. That’s why scanning for codes is critical.

ICM will nor prevent a scanner from connecting. No “sensor” will prevent a scanner from connecting.

I'll ask this question for the third (or is it the fourth) time. I scanned the posts above and didn’t see a response. That’s why I wasn’t going to continue with this thread.

WHEN THE STARTER IS CRANKING THE ENGINE, DOES THE TACH NEEDLE MOVE UP ABOUT 200 RPM?

When you turn the key to “RUN” does the fuel pump prime for two seconds and then turn off?

http://shbox.com/1/fuel_pump_prime.jpg

If not, apply 12 volt power to the fuel pump prime connector under the hood, near the PCM. That should cause the fuel pump to run. If it doesn’t run, with the prime connector still powered, you will need to see if you are getting 12 volts on the gray wire at the fuel pump relay. Relay is behind the kick panel neardriver's left leg.

http://shbox.com/1/fuel_pump_relay.jpg

scope513

Sorry didnt answer it yet until I got the new battery in. Sometimes I get frustrated and get overwhelmed. No rpms at all. No buzzing sound either. Is there a certain gauge wire to directly connect it to the prime? Then if it doesnt prime I'll check the relay, I replaced that too..but it could be the wire. Ac or Dc? Also didnt get spark when I connected the coil wire to spark tester (the one from coil to opti).

Injuneer

A short length of 12 or 14 gage wire, directly from the red plastic + junction box near the battery. I would put a 20 amp fuse in the wire. All voltages are DC. There is no AC in the car other than a couple of square wave and pulsed signals and the alternator, which includes a rectifier that produces DC power.

Earlier you said you had a damaged connector at the fuel pump. Did you replace the connector? With 12 volts on the prime connector, measure the voltage at the fuel pump connector. You should have 12 volts between the gray wire (12 V) and the black wire (ground).

http://shbox.com/1/fuel_pump_connector.jpg

If the tach needle does not move upwards a bit when the starter is cranking the engine there’s a good chance the Opti is a problem. No spark condition may also be pointing to the Opti.

scope513

Ok will do it today when I get back home. Ill take pics and post, hopefully I figure it out.

scope513

Ok so I applied 12v to prime...the pump is priming, but when I primed, a gas smell back where the pressure regulator is and a liquid (assuming fuel through the system) was quite noticeable. I did take off gas cap for nephew to listen to the hum. There was a hum. Maybe the fuel cap being taken off while priming made the liquid sound? I still got to check for 12 at gray and black wire (cold and no floor jack). Im curious on why the fuel smell. I felt around the fuel press. reg. vacuum line, and pressed the Schrader valve, It still had pressure. And no signs of cracks or leaks on the line. By the way injuneer, thank you so much for walking me through this.

scope513

Did the 20 amp and 14g. Wire

To the primer (black single wire )

scope513

Oh and I checked for spark at from coil not #1 plug. No spark.

Injuneer

Did you pull the vacuum line off the fuel pressure regulator? There's a diaphragm in the regulator that can leak and allow fuel to enter the vacuum line.

There is an O-ring on the part of the regulator that fits into the fuel rail, and another on the hard line that inserts into the regulator.

From Shoebox:

http://shbox.com/1/fuel_rail_94-97.jpg

If the fuel lines were full of air, it is possible that made noise as the fresh fuel forced it through the rails, into the regulator, and out into the return line.

scope513

Put tank cap back on and primed, for a brief second it made oula sound then stopped. Im assuming fully primed again. So I know the pump is good atleast. So eliminating that it has to be electrical. Im guessing some sort of wire or or sensor. And still obd2 wont connect and no spark from coil. In other posts it might be a crankshaft sensor (can stop spark and fuel) or possibly a relay? I bought a relay for pump and ignition switch. Battery is still good, and Ill check my grounds again. Can I put dielectric grease on grounds(where they meet the engine and body)? Also going to check wires for continuity and fuse box. What terminals should I check on the relays?

Injuneer

The crankshaft position sensor on an LT1 doen’t control anything, does not affect how the engine runs, will not shut down fuel or ignition. It was only added in 1996 for the misfire detection required by OBD-2. 93-95 LT1’s don’t have a crank position sensor. The critical piece is the camshaft position sensor. That is inside the Opti, and is the “optical” part of “Optispark”. The fact your tach doesn’t move when the engine is cranking likely indicates the cam position data is not reaching the PCM.

The PCM won't restart the fuel pump unless it gets 1) the low resolution cam position pulses from the Opti; and 2) the fuel enable signal (part of VATS) from the BCM. I mentioned in post #4 that the only sensor that will shut down the engine is the cam position sensor in the Opti.

scope513

What would be the most effective and efficient way to check opti(least amount of assembly but still be able to rule it out)? How can I rule out the relays?

scope513

Thinking back does the opti make a sound when the ignition is in the on position?

scope513

Ok, so cranksensor is ruled out of no start condition. Check. Opti was brand new and installed, I did it myself (but Ive heard people have a huge problem installing properly). I used the same dowel pin that was originally on it when it was running, put new seals on (water pump, timing cover). It went on fairly easy besides when I had to give it a little effort because of o-rings. Reading through your posts injuneer, Its leading more towards opti or possible bad wire somewhere. Which wires (location and color) should I check? Again thank you for your patience.