1993C4LT1

When I start my car in the garage, cold, it has a strong fuel smell. When the engine warms up, the smell is still there. Not as strong, but still there. When I drive the car, I smell no gas in the interior. Windows down, no gas smell either. Here is what my car has new, intake and valve cover gaskets, opti, plugs, spark plug wires, fuel pressure regulator, and rebuilt injectors from FIC(Bosch III). Any ideas on what is causing the fuel smell from the tail pipes?

THE 383 admiral

Are you sure you do not.
Have pin holes in the bottom of the fuel tank
My 94 & 95 had pin holes. small enough to leak
Yet not leave a puddle. These tanks are paper thin
Both I cleaned. And easily & permanently repaired with magnum steel knead putty.
The bosch III same flow/pound rate?

1993C4LT1

What do you mean by"are you sure you do not."? They are same as the factory, 24lb. What are the pinholes?

Chad30021

There are a few things you can check. First look at the fuel rail and make sure that the injector o rings are firmly seated in the intake manifold and the rail. Make sure the rail is bolted down flush with the intake manifold. Next check the connection where the flow and return line is attached on the rail and ensure those quick disconnect fittings do not have any sort of leak. Then check the fuel filter make sure it is not leaking either. What you may also be smelling is a Cat Convertor going bad. When they start to wear the exhaust has a strong fuel smell becuase they are not doing there jobs correctly. I hope this helps!

EDIT: also you can check the evap cannister where the fuel vapors return to front of the car. Any leak in that system via a cracked line will allow a strong fuel smell because it is vapors straight from the tank. However that sort of leak will post a CEL code about an emissions leak (most people think its a gas cap)

1993C4LT1

O rings are snug, so is the fuel rail. I see no signs of leaks on the fuel filter. No check engine light.

JoeUser

Possible worn out O2 sensor(s)? Causing the computer to enrich the mixture too much at startup? O2 sensor accuracy declines over time, and are parts that will go bad eventually, IMO.

I have a similar issue with my '96. Upon startup the exhaust smells rich, but after warm-up none that I can smell. But, I have 105K on mine (and, new sensors are sitting on the workbench, waiting to be installed - along with new injectors and FPR).

1993C4LT1

That's really the only thing I can think of, the o2 sensors. Just wanted to ask here for other opinions. Do you all think that with 78k miles, the o2's are bad? I think my cats are good, because my car isn't having trouble going up to redline. Anyway to test for bad 02's?

THE 383 admiral

Sorry!! 93 without a color code, flow chart or part # you could have any injector.. microscopic holes in the bottom of the tank. Ps i noticed the ethanol
Destroyed my rubber vap hoses

1993C4LT1

Well the injectors I got from FIC said they are for the 93 lt1 only. I spoke with Jon on the phone to verify. The injectors did smoothen the idle at stop lights. I'll check the vap hoses. Where are they?

THE 383 admiral

Behind your right rear wheel hiding behind the 1/4 support. Also leading under the right side hood ending in your intake.. the good news. The main from vap to blower motor area is PVC

1993C4LT1

Do I need to check the PCV hose for cracks or whatever? Sorry, new to this stuff. By intake, do you mean the air intake, or what the fuel rail sits on top of?

Cliff Harris

I know they moved the charcoal canister to the rear of the car sometime in the '90s. Did you check the connections between the fuel tank and the canister?

On earlier years with the canister in the front, there is a short rubber hose in the vapor lines just in front of the driver's side rear tire. That hose has been known to deteriorate and cause a fuel smell.

1993C4LT1

I can't find the charcoal cannister. I'll pull the o2 sensors to see if they look bad.

1993C4LT1

I know one of these connects to the cannister. Should I replace them? Not sure if you can see, but there are tiny cracks

Pete919

If your going through the hassle of pulling the o2 sensors and they are original, I would replace them. Spray them ahead of time with pb blaster or something similar.

1993C4LT1

Thanks. I have no clue as to if they were changed or not. I only spray the threads right?

Pete919

Yes. Just curious, did you ever check the fuel pressure? If its low i think the computer may add fuel as joeuser alluded to.

1993C4LT1

No, I haven't. But I will today or tomorrow morning.

1993C4LT1

Look bad?

JoeUser

I only replaced the pre-cat sensor on the passenger side (so far), until I can get to a lift and to the other three sensors more easily. However, that one of mine didn't look that dark.

In any case, I don't think that appearance really indicates whether it's bad or not (unless I'm wrong, which I am a lot, regarding vettes, I'm finding - lol)...