I have a 1994 v6 3.4 camaro and I had a new fuel tank installed, but my mechanic cannot figure out why my car is leaking fuel near the rear of my car...and now my car will not start

more likely gas is leaking from the gas tank not oil. maybe you blew a rear shock instead?

i would suspect the fuel pump ,could be the filter in the tank on the bottom of the fuel pump is dirty -Now why this should be ?? but i would remove the fuel pump and check this first

Park the Camaro on a flat, level surface and set the parking brake. Open the hood and secure it in place with the hood prop. Disconnect the negative battery cable.

Open the gas tank to relieve pressure on the fuel lines.

Remove the sight shield from the fuel injector with a socket wrench. Loosen the screws on the hose clamps and disconnect the fuel lines connected to the injectors. Keep a rag handy to catch any fuel that leaks.

Disconnect the vacuum hose and ignition coil wire, then unplug the electrical connectors. Remove the fuel injector mounting bolts, undo the retaining clips and remove the fuel injectors.

Put a thin coat of engine oil on the new fuel injector's O-ring. Place the O-ring in position, install the new fuel injectors and secure the retaining clips. Install the mounting bolts with a torque wrench set at seven pounds.

Plug the electrical connectors back into the fuel injectors. Reconnect the vacuum hose and ignition coil wire. Connect the fuel lines and tighten the hose clamps with a screwdriver to secure them in place. Bolt the sight shield in place with a socket wrench.

Place the gas cap back on. Reconnect the negative battery cable

In the gas tank, not an easy job on this type of car exhaust tail pipe will have to come down to make room for the gas tank to come down.

GM Camaro/Firebird 1993-1998 Repair Guide Fuel Pump - REMOVAL & INSTALLATION
(see Figures 1 and 2)
The fuel pump is part of the fuel sender assembly located inside the fuel tank.

1. Release the fuel system pressure and disconnect the negative battery cable.
2. Drain the fuel tank, then raise and safely support the vehicle.
3. Remove the fuel tank from the vehicle.
4. Clean the area surrounding the sender assembly to prevent contamination of the fuel system.
5. To remove the fuel sender from the tank, remove the fuel sender assembly nuts and retaining ring. Carefully remove the sending unit from the fuel tank. Discard the O-rings.
   

Fig. 1: Exploded view of the fuel tank and sender assembly

1. If necessary, separate the fuel pump from the sending unit assembly.
   

Fig. 2: Fuel sender and pump assembly


To install:

1. If removed, install the fuel pump to the sending unit. If the strainer was removed, it must be replaced with a new one.
2. Inspect and clean the O-ring mating surfaces.
3. Install a new O-ring in the groove around the tank opening. If applicable, install a new O-ring on the fuel sender feed tube.
4. Install the fuel sender assembly as follows:
   1. The fuel pump strainer must be in a horizontal position, and when installed, must not block the travel of the float arm. Gently fold the strainer over itself and slowly position the sending assembly in the tank so the strainer is not damaged or trapped by the sump walls.
      
5. Install the retaining ring and nuts, then tighten the nuts to 63 inch lbs. (7 Nm).
6. Install the fuel tank assembly.
7. Lower the vehicle.
8. Fill the fuel tank, tighten the fuel filler cap and connect the negative battery cable.
9. Turn the ignition switch to the ON position for 2 seconds, OFF for 10 seconds, then back to the ON position. Check for fuel leaks.

Hope this help (remember rated this post). Good luck.

Camaro, Firebird, 1999 - 2002 Repair Guide
Fuel Pump - Removal & Installation

1. Before servicing the vehicle, refer to the Precautions Section.
   
2. Relieve the fuel system pressure.
3. Drain the fuel tank.
4. Clean the area surrounding the sender assembly to prevent contamination of the fuel system.
5. Remove or disconnect the following:
   Fuel tank Fuel sender-to-fuel tank retaining ring Fuel sender from the fuel tank Fuel pump from the sending unit
   
   
   Fig. Fuel sender/pump assembly component identification
   

To install:

1. Install or connect the following:
   NOTE The fuel pump strainer must be in a horizontal position and must not block the float arm travel.
   Fuel pump with new strainer onto the sending unit New O-ring in the tank opening groove New O-ring on the fuel sender feed tube
2. Fold the strainer over itself and slowly position the sending assembly in the tank so the strainer is not damaged or trapped by the sump walls.
   Retaining ring Fuel tank. Torque the bolts to 33 ft. lbs. (45 Nm). Fuel filler cap Negative battery cable
   
3. Turn the ignition switch to the ON position for 2 seconds, OFF for 10 seconds, then back to the ON position. Check for fuel leaks.

Hope this help (remember rated and comment this), good luck.

remove fuel tank, pump inside fuel tank

your spark plugs and wires is bad or intake manifold leak and a stop up fuel filter will cause hard cold start ups in morning.

this one isnt the funnest ...fuel tank must be removed which requires dropping rear end diff. and exhaust far enough to access tank. most helpfull if fuel tank is low or out of gas....even with this,lifting car and jacks required.

The fuel pump is in the gas tank. To replace it you need to drain most of the fuel out of the tank and remove the tank from the car. The car needs to be lifted up in the air enough to slide the tank from under the car. There is a metal ring on the top of the tank and it needs to be removed jently with a screw driver and a small hammer. This part (fuel sending unit) is worth lots of money so do not damage it. The pump is in the tank and will come out when the metal retaining ring/ fuel sending unit is removed. Install the new pump the same way the old one came out and reverse these steps for installation.
It may be possible to make the pump work for a short while if you hit the bottom of the fuel tank in the middle with a hammer.