How do I know if my carburetor is rich or lean?
Typical symptoms of a rich mixture are:
- Poor fuel economy.
- Sluggish acceleration.
- Choke not needed from cold starts.
- Sooty or black spark plugs.
- Sooty or black muffler end pipes.
- Strong smell of gasoline when the machine is at idle.
- Uneven running (will often slow from regular idle rpms and then stop)
Can I drive with a bad air fuel ratio sensor?
Driving with a faulty O2 sensor means the computer won’t be getting the correct reading of the mixture and hence it won’t be able to adjust the air-fuel mixture properly. But if your engine starts and runs, and can stay running, it’s drivable.
What causes a rich air/fuel mixture?
This is when there are just enough parts of air (14.7) to burn one part of fuel with no excess oxygen or fuel left over. Faulty components such as dripping fuel injectors, fuel pressure regulators, ECT’s and stuck open thermostats cause this problem.
What does a bad air fuel ratio sensor do?
If an air-fuel ratio sensor has become “lazy,” over time it will send a delayed signal to the computer, which will result in an overall delayed response for the entire engine. The vehicle may experience a sluggish or delayed response when accelerating, as well as a noticeable loss in power and acceleration speed.
What should AFR be at idle?
How does it affect performance?
| Gasoline AFR | Methanol AFR | |
|---|---|---|
| Cruise | 14.7-15.5 | 6.4-6.8 |
| Idle | 13.5-15.0 | 6.0-6.6 |
| Stoich | 14.7 | 6.4 |
| WOT | 11.5-13.3 | 5.1-5.8 |
What is the best air fuel ratio?
around 14.7:1
What AFR makes the most power?
Maximum power is usually found between 12-14:1, but this may be too lean for safety on many engines. For maximum reliability at full power, air/ fuel ratios from 10.5-12.5:1 are considered best, depending on the engine.
How can I make my car run richer?
To run richer put a restricter in the return fuel line small enough to up the fuel pressure . You can make it adjustible so you can control the fuel . The same duty cycle ( stock ECU )with higher pressure will give you more fuel . Note that increased fuel pressure will richen the mixture at idle & cruise too.
What is a good AFR reading?
Most stock to slightly modified engines will run just fine at an AFR of 15:1 and yield better MPG. If you prefer better PERFORMANCE then we suggest to run an AFR of 14:1 or even richer to around 13.5:1. Most stock to slightly modified engines will run just fine at an AFR of 14.5:1 and yield better MPG.
What should air fuel ratio be at WOT?
We mentioned the stoichiometric air-fuel ratio (14.7:1) that is the ideal ratio for lowest emissions, but this isn’t the best ratio for power. It used to be that 12.5:1 was considered the best power ratio, but with improved combustion chambers and hotter ignition systems, the ideal now is around 12.8:1 to 13.2:1.
How can I make my old engine run better?
So, to keep your car running smooth, make sure you have the following engine-related services done regularly:
- Change the oil.
- Change the oil filter, air filter and fuel filter.
- Check the PCV valve for proper operation.
- Check the spark plugs and spark plug wires.
- Very Hard – 10.5 and higher gpg.
What keeps an engine running?
Causes of running on Running-on occurs when the fuel/air mixture in the cylinders ignites without a spark. This is known as the dieselling effect because it is caused by the fuel igniting spontaneously in the combustion chambers, which is what occurs (deliberately) in a diesel engine.