Solving Misfire in CNG Engine: Q&A

[tworitdash]

I have some questions regarding my observations of a misfiring bi-fuel vehicle (CNG and Gasoline).

1. For same misfire rates, in Gasoline mode, the exhaust catalyst temperature is higher than the in CNG mode.

2. For lower misfire rates, in CNG, the temperature is higher than with higher misfire rates, which is unusual as far as misfire is concerned.

3. At lower misfire rates (less than 10), the temperature with CNG is higher than Gasoline.

I have searched for fuel type specific explanations for these observations, but hardly I could get a proper answer which explains why it's happening. I have got explanations with latent heat of CNG and Gasoline and explanations like more CNG gas cooling the catalyst because the molecule size is very less in CNG than Gasoline.

That's why I wanted to get a proper explanation to this.

 

[jerromyjon]

I have searched for fuel type specific explanations for these observations, but hardly I could get a proper answer which explains why it's happening. I have got explanations with latent heat of CNG and Gasoline and explanations like more CNG gas cooling the catalyst because the molecule size is very less in CNG than Gasoline.

I am barely aware of the implications, but I offer this tid-bit. Compressed Natural Gas would have far less CO₂ emissions and require obviously less catalysis than gasoline combustion emissions.