Fuel smell on '93 LT1
Thread Starter
Race Director
Joined: Oct 2011
Posts: 16,076
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From: Dallas Texas
2025 C4 of the Year Finalist - Modified
Fuel smell on '93 LT1
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?
Melting Slicks
Joined: Sep 2010
Posts: 2,422
Likes: 202
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?
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?
Instructor
Joined: Sep 2012
Posts: 125
Likes: 5
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)
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)
Instructor
Joined: Aug 2012
Posts: 213
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From: Carrollton TX
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).
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).
Thread Starter
Race Director
Joined: Oct 2011
Posts: 16,076
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From: Dallas Texas
2025 C4 of the Year Finalist - Modified
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?
Melting Slicks
Joined: Sep 2010
Posts: 2,422
Likes: 202
Destroyed my rubber vap hoses
Last edited by THE 383 admiral; Nov 18, 2014 at 08:16 PM.
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Thread Starter
Race Director
Joined: Oct 2011
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From: Dallas Texas
2025 C4 of the Year Finalist - Modified
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?
Last edited by 1993C4LT1; Nov 18, 2014 at 08:26 PM.
Thread Starter
Race Director
Joined: Oct 2011
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From: Dallas Texas
2025 C4 of the Year Finalist - Modified
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?
Race Director
Joined: Apr 2002
Posts: 10,036
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From: Anaheim CA
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.
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.
Instructor
Joined: Nov 2012
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From: Long Island
Instructor
Joined: Nov 2012
Posts: 214
Likes: 7
From: Long Island
Thread Starter
Race Director
Joined: Oct 2011
Posts: 16,076
Likes: 816
From: Dallas Texas
2025 C4 of the Year Finalist - Modified
Instructor
Joined: Aug 2012
Posts: 213
Likes: 0
From: Carrollton TX
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)...
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)...