C6 Running Rich?
Thread Starter
Intermediate
Joined: Aug 2023
Posts: 33
Likes: 1
C6 Running Rich?
I have a C6 08 Auto with 40k miles
When hard accelerating I notice a burn smell, it goes away when casual cruising. I read somewhere that it can be a rich fuel mixture. If so, what can lead it to running rich?
When hard accelerating I notice a burn smell, it goes away when casual cruising. I read somewhere that it can be a rich fuel mixture. If so, what can lead it to running rich?
Race Director
Joined: Dec 2013
Posts: 12,502
Likes: 3,629
At WOT, motor runs on all tune, since system goes into open loop during WOT.
So car running slightly richer than 14.7afr at WOT throttle, the norm (about 13.9FR).
Running way rich at WOT, with say under 13.5 AFR, could be the car was after market turned to run this much richer to make more power, or air filter is clogged, and why it running that much richer at WOT instead.
So real question, is smell like unburnt petrol, or more like rubber instead.
If rubber, could be belt slipping, or even coupler in the TT going out, and smelling it rubbing on the inside or the TT,
https://preview.redd.it/blown-out-to...=webp&d619e405
So car running slightly richer than 14.7afr at WOT throttle, the norm (about 13.9FR).
Running way rich at WOT, with say under 13.5 AFR, could be the car was after market turned to run this much richer to make more power, or air filter is clogged, and why it running that much richer at WOT instead.
So real question, is smell like unburnt petrol, or more like rubber instead.
If rubber, could be belt slipping, or even coupler in the TT going out, and smelling it rubbing on the inside or the TT,
https://preview.redd.it/blown-out-to...=webp&d619e405
Thread Starter
Intermediate
Joined: Aug 2023
Posts: 33
Likes: 1
At WOT, motor runs on all tune, since system goes into open loop during WOT.
So car running slightly richer than 14.7afr at WOT throttle, the norm (about 13.9FR).
Running way rich at WOT, with say under 13.5 AFR, could be the car was after market turned to run this much richer to make more power, or air filter is clogged, and why it running that much richer at WOT instead.
So real question, is smell like unburnt petrol, or more like rubber instead.
If rubber, could be belt slipping, or even coupler in the TT going out, and smelling it rubbing on the inside or the TT,
https://preview.redd.it/blown-out-to...=webp&d619e405
So car running slightly richer than 14.7afr at WOT throttle, the norm (about 13.9FR).
Running way rich at WOT, with say under 13.5 AFR, could be the car was after market turned to run this much richer to make more power, or air filter is clogged, and why it running that much richer at WOT instead.
So real question, is smell like unburnt petrol, or more like rubber instead.
If rubber, could be belt slipping, or even coupler in the TT going out, and smelling it rubbing on the inside or the TT,
https://preview.redd.it/blown-out-to...=webp&d619e405
Pro
Joined: Oct 2008
Posts: 706
Likes: 265
From: Jyväskylä, FINLAND
At WOT, motor runs on all tune, since system goes into open loop during WOT.
So car running slightly richer than 14.7afr at WOT throttle, the norm (about 13.9FR).
Running way rich at WOT, with say under 13.5 AFR, could be the car was after market turned to run this much richer to make more power, or air filter is clogged, and why it running that much richer at WOT instead.
So real question, is smell like unburnt petrol, or more like rubber instead.
If rubber, could be belt slipping, or even coupler in the TT going out, and smelling it rubbing on the inside or the TT,
https://preview.redd.it/blown-out-to...=webp&d619e405
So car running slightly richer than 14.7afr at WOT throttle, the norm (about 13.9FR).
Running way rich at WOT, with say under 13.5 AFR, could be the car was after market turned to run this much richer to make more power, or air filter is clogged, and why it running that much richer at WOT instead.
So real question, is smell like unburnt petrol, or more like rubber instead.
If rubber, could be belt slipping, or even coupler in the TT going out, and smelling it rubbing on the inside or the TT,
https://preview.redd.it/blown-out-to...=webp&d619e405
Drifting
Joined: Jul 2011
Posts: 1,825
Likes: 443
From: Boca Raton Florida
This is not one of this easy pickings, I smell gas it must be runing rich. There are few other reasons you could smell gas, EVAP sytem and or a cracked fuel line at the gas tank. Car must be monitored while running on short and long term fuel trims, and other parameters while this happens. You need to find a shop that works on our cars to sort this out. It is a complicated piece of engineering.
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,600
Likes: 4,057
From: Cape Coral, Florida
Can be an O2 sensor stuck “lean” or possibly an EVAP purge valve stuck open…you really need a diagnostic shop to interpret your fuel trims and other data PIDS…does not have to be a Corvette “specialist” shop…any good diagnostician should be able to tell you what’s wrong !!
