Fuel smell on '93 LT1
11-19-2014, 11:02 PM
#22
I know one of these connects to the canister. Should I replace them? Not sure if you can see, but there are tiny cracks. And yes look on the side of the intake hose barb fittings.
Attachment 47841912
Attachment 47841912
Check for more like that!!
11-20-2014, 12:55 AM
#23
Team Owner
Pro Mechanic
First, let's diagnose, before we start throwing parts at the car.
Second, the OP's car has two O2 sensors...not 4. It's an OBD1 car, so it only has two sensors.
Third. O2 sensors don't function at start up/cold start! Engine has to be in closed loop for the O2's to function or have an effect on how the car runs. For that to happen, they have to be over ~600*F, engine has to be over ~145*F and other conditions have to be met.
The OP is complaining of fuel odor at start up. The logical thing to do here would be to pursue fuel leakage and or EVAP system leakage.
11-20-2014, 02:19 PM
#24
Instructor
Member Since: Aug 2012
Location: Carrollton TX
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Ah, thanks for the correction. I didn't know that the O2 sensors didn't come into play until in closed loop. My mistake (file away in gray matter for future reference, doh!).
Also, thanks for clearing up the number (totally forgot that mine is ODBII and have both pre- and post-cat).
Also, thanks for clearing up the number (totally forgot that mine is ODBII and have both pre- and post-cat).
11-20-2014, 06:30 PM
#25
Burning Brakes
Guys.
First, let's diagnose, before we start throwing parts at the car.
Second, the OP's car has two O2 sensors...not 4. It's an OBD1 car, so it only has two sensors.
Third. O2 sensors don't function at start up/cold start! Engine has to be in closed loop for the O2's to function or have an effect on how the car runs. For that to happen, they have to be over ~600*F, engine has to be over ~145*F and other conditions have to be met.
The OP is complaining of fuel odor at start up. The logical thing to do here would be to pursue fuel leakage and or EVAP system leakage.
First, let's diagnose, before we start throwing parts at the car.
Second, the OP's car has two O2 sensors...not 4. It's an OBD1 car, so it only has two sensors.
Third. O2 sensors don't function at start up/cold start! Engine has to be in closed loop for the O2's to function or have an effect on how the car runs. For that to happen, they have to be over ~600*F, engine has to be over ~145*F and other conditions have to be met.
The OP is complaining of fuel odor at start up. The logical thing to do here would be to pursue fuel leakage and or EVAP system leakage.
11-23-2014, 07:00 PM
#27
Ah, thanks for the correction. I didn't know that the O2 sensors didn't come into play until in closed loop. My mistake (file away in gray matter for future reference, doh!).
Also, thanks for clearing up the number (totally forgot that mine is ODBII and have both pre- and post-cat).
Also, thanks for clearing up the number (totally forgot that mine is ODBII and have both pre- and post-cat).
94 - 95 is the 1st design of the OBD II system
11-23-2014, 07:05 PM
#28
Burning Brakes
11-23-2014, 07:11 PM
#29
Race Director
Thread Starter
Well guys, I've replaced two vacuum leaks. When the car is warm, I smell no fuel like I use to. Now it seems I have a miss or an exhaust leak.
Can't tell, I'll post a vid tomorrow morning.
Can't tell, I'll post a vid tomorrow morning.
11-23-2014, 11:25 PM
#32
Thank you, for trying to correct me.
again as I said 94 - 95 is what GM used to develop OBD II.. I know it communicates via OBD 1 with a OBD II 'ALDL' port it has two systemboards it is way beyond OBD 1 it actually has some features OBD II does not have.
again as I said 94 - 95 is what GM used to develop OBD II.. I know it communicates via OBD 1 with a OBD II 'ALDL' port it has two systemboards it is way beyond OBD 1 it actually has some features OBD II does not have.
Last edited by THE 383 admiral; 11-23-2014 at 11:27 PM.
11-24-2014, 09:43 AM
#33
11-24-2014, 09:58 AM
#34
Burning Brakes
That explains why many places call it OBD1.5. I never bothered to find out more.
12-12-2014, 11:07 PM
#35
i just found that my Fuel pressure regulator had a leak will this be the reason why i have a gas smell in the exhaust? and now i have the smell all the time in the exhaust!.
12-21-2014, 12:31 AM
#39
Instructor
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?
12-21-2014, 09:05 AM
#40
Race Director
Thread Starter
Check the cross-over tubes on the fuel rails. They are at the back of the rails and when the motor is hot it makes the gas that is leaking evaporate. When it sits and the rails are still under pressure it lets the gas stink up the garage. Went through this myself and it was nothing more than a couple of O-Rings and it was after I had replaced injectors and FPR that I noticed it. Run your finger under the fuel rails at the cross-over tubes and if it shows raw gas on your fingers or smells of gas then that is where you will want to start.