Running Rich, how to fix?
Thread Starter
Intermediate
Joined: Jan 2006
Posts: 34
Likes: 0
From: Norfolk Virginia
Running Rich, how to fix?
hello,
i have a 1987 corvette Z51 and i was wondering how i might go as to fixing a fuel problem. ok, heres how it goes: when i turn my car on, like not even 1 minute later you can smell gas from inside the cab and outside. and someone mentioned to me that my car is running rich in the fuel/air mixture. and i dont know how to fix this just yet but i will hope my fellow drivers here have experience with this problem. any help would be greatly appreciated.
thx
i have a 1987 corvette Z51 and i was wondering how i might go as to fixing a fuel problem. ok, heres how it goes: when i turn my car on, like not even 1 minute later you can smell gas from inside the cab and outside. and someone mentioned to me that my car is running rich in the fuel/air mixture. and i dont know how to fix this just yet but i will hope my fellow drivers here have experience with this problem. any help would be greatly appreciated.
thx
Former Vendor
Joined: Jun 2001
Posts: 7,204
Likes: 6
From: St Marys PA
Originally Posted by 87~C4~Driver
hello,
i have a 1987 corvette Z51 and i was wondering how i might go as to fixing a fuel problem. ok, heres how it goes: when i turn my car on, like not even 1 minute later you can smell gas from inside the cab and outside. and someone mentioned to me that my car is running rich in the fuel/air mixture. and i dont know how to fix this just yet but i will hope my fellow drivers here have experience with this problem. any help would be greatly appreciated.
thx
i have a 1987 corvette Z51 and i was wondering how i might go as to fixing a fuel problem. ok, heres how it goes: when i turn my car on, like not even 1 minute later you can smell gas from inside the cab and outside. and someone mentioned to me that my car is running rich in the fuel/air mixture. and i dont know how to fix this just yet but i will hope my fellow drivers here have experience with this problem. any help would be greatly appreciated.
thx
If its just rich smelling from the exhaust, what has been done to your car? Mods, injector change?
Thread Starter
Intermediate
Joined: Jan 2006
Posts: 34
Likes: 0
From: Norfolk Virginia
well i can smell it in the interior and on the outside and the smellis sorta like paint thinner or finger nail polish remover.
it worries me
the only mod that i realy have is a K&N filter, i just bought the car like 2 months ago (my first vette) yippy
it worries me
the only mod that i realy have is a K&N filter, i just bought the car like 2 months ago (my first vette) yippy
Burning Brakes
Joined: Nov 2005
Posts: 848
Likes: 1
From: 1992 LT1 6 speed Cayman Islands
O2 sensor
Pull your O2 sensors and see if they are coated with oil or carbon. A coated or bad O2 sensor will send a signal to the ECM that the car is running lean when it is in fact not and the ECM will send a signal to the injectors to increase the amount of fuel to compensate for what it thinks is a lean mixture.
An O2 sensor that is going bad in this fashon will not set a code because the signal it is sending when the mixture is rich (in error), is the same as a properly functioning O2 sensor sends when the mixture is correct.
Jerris
An O2 sensor that is going bad in this fashon will not set a code because the signal it is sending when the mixture is rich (in error), is the same as a properly functioning O2 sensor sends when the mixture is correct.
Jerris
Former Vendor
Joined: Jun 2001
Posts: 7,204
Likes: 6
From: St Marys PA
I would try to track down if its coming from the exhaust, rich smell, or if its "fuel" leaking smell.
Pull the plugs out and see what they look like. If its the 02 and its that bad, they too will be charcoal black.
Pull the plugs out and see what they look like. If its the 02 and its that bad, they too will be charcoal black.
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Burning Brakes
Joined: Nov 2005
Posts: 848
Likes: 1
From: 1992 LT1 6 speed Cayman Islands
If the O2 sensor is contaminated with oil, cleaning them may not help. The voltages produced by them are so small that any film left on them by burning oil will still make them read low. It is worth a try to clean them with a throttle body cleaner (not a carb cleaner as they will often also leave a film) to see if there is any improvement at all, but if this does not completely cure the problem you may have to replace them.
Jerris
PS a high smell of raw fuel can also be from an injector that is stuck open.
Jerris
PS a high smell of raw fuel can also be from an injector that is stuck open.
Team Owner
Joined: Sep 2001
Posts: 62,160
Likes: 1,733
From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
The problem is not a faulty O2 sensor. That is why I asked his fuel mileage, which is actually above average. If he's getting that mileage then it isnt coated with carbon.
The fault will be with one or two injectors flooding their cylinder on shutdown and it staying there until the next startup, and the smell being passed out of the engine. Best bet is to pull each plug and notice its coloring. Then I would install a fuel pressure gauge at the rail and shut the car off, if the pressure drops then an injector failure has occured.
I suppose it could also be vapor canister related.
The fault will be with one or two injectors flooding their cylinder on shutdown and it staying there until the next startup, and the smell being passed out of the engine. Best bet is to pull each plug and notice its coloring. Then I would install a fuel pressure gauge at the rail and shut the car off, if the pressure drops then an injector failure has occured.
I suppose it could also be vapor canister related.
Last edited by vader86; Feb 6, 2006 at 07:02 PM.
Safety Car
Joined: Feb 2002
Posts: 4,212
Likes: 10
From: Sun City West Az
Originally Posted by vader86
The problem is not a faulty O2 sensor. That is why I asked his fuel mileage, which is actually above average. If he's getting that mileage then it isnt coated with carbon.
The fault will be with one or two injectors flooding their cylinder on shutdown and it staying there until the next startup, and the smell being passed out of the engine. Best bet is to pull each plug and notice its coloring. Then I would install a fuel pressure gauge at the rail and shut the car off, if the pressure drops then an injector failure has occured.
I suppose it could also be vapor canister related.
The fault will be with one or two injectors flooding their cylinder on shutdown and it staying there until the next startup, and the smell being passed out of the engine. Best bet is to pull each plug and notice its coloring. Then I would install a fuel pressure gauge at the rail and shut the car off, if the pressure drops then an injector failure has occured.
I suppose it could also be vapor canister related.
Le Mans Master
Joined: Feb 2002
Posts: 7,858
Likes: 2
Originally Posted by 87~C4~Driver
city its like 18/ hwy is like 25-30 depending on my speed
ie. 70mph 4th gear OD like 30 +/-3 mpg
ie. 70mph 4th gear OD like 30 +/-3 mpg
Former Vendor
Joined: Jun 2001
Posts: 7,204
Likes: 6
From: St Marys PA
Sounds like its time to change the plugs, keep track of them and you will likely find out which of them are running rich.
I would change out the plugs and wires, distributer cap and then monitor the car after the change to see if it gets any better. If it doesn't then I would pull all the plugs and since they are fresh - you will be able to tell if and which injector is the problem. At which time you can decide what you want to do.
There is a good chance that the previous owner did not change out these items for a good long time. I know when I bought my car, they were the stock wires and stock plugs. Car only had about 30k miles on it, but none the less they were 11year old wires, which upon inspection were cracked and dry rotting - since then - the fun has not stopped.
I would change out the plugs and wires, distributer cap and then monitor the car after the change to see if it gets any better. If it doesn't then I would pull all the plugs and since they are fresh - you will be able to tell if and which injector is the problem. At which time you can decide what you want to do.
There is a good chance that the previous owner did not change out these items for a good long time. I know when I bought my car, they were the stock wires and stock plugs. Car only had about 30k miles on it, but none the less they were 11year old wires, which upon inspection were cracked and dry rotting - since then - the fun has not stopped.
Thread Starter
Intermediate
Joined: Jan 2006
Posts: 34
Likes: 0
From: Norfolk Virginia
ok heres the situation right now i have ran the car kind of hard for about 5 mins and normal driving for about 5 mins and when i put it in a parking spot i took a wiff of the exhuast and i smelled no trace of fuel, this was after 10 mins of driving hard/normal and the coolant temp was about 145*F.
and i still dont know if this info will help you guys help me but i think when i get my taxes back (feb 10th) i wil get my car tuned up : new plugs, wires, dist., oil change, grease some u-joints, and steam clean my engine.
and i will see what goes on from there, but i will def. check the fuel injectors and thx for all the info. i will see what i can do with all your help.
and i still dont know if this info will help you guys help me but i think when i get my taxes back (feb 10th) i wil get my car tuned up : new plugs, wires, dist., oil change, grease some u-joints, and steam clean my engine.
and i will see what goes on from there, but i will def. check the fuel injectors and thx for all the info. i will see what i can do with all your help.
Safety Car
Joined: Dec 2004
Posts: 4,088
Likes: 0
From: Poop land
Maybe someone like a previous owner gutted your cats. My Vette has NEVER had cats and it smells similar to what you are describing. More like exhaust though. I'd check to see if your EECS is working properly.
Burning Brakes
Joined: Jun 2004
Posts: 752
Likes: 0
From: richardson tx
i dont think its a rich condition as stated in the gm books cause as soon as the ecm starts reading the 02 you would be having noticiable drive ability problems as the ecm would be trying to comensate for the extra fuel in the exhaust stream. cutting back on the pulse width ect.. maybe some stalling or less than normal power while driving. does the fumes burn your eyes?