Has anybody owned a CNG car ?

[cjcride]

As Garak said cold starts are the weak point. We had some years back in the fleet.
Leaks in closed quarters are down right dangerous, otherwise burns very clean and thorough runs a bit hotter I believe.

 

[Garak]

Fortunately, the inspection regime here was pretty good. There was only one accident involving propane here over the years, in my recollection. Some guys decided to remove the propane system from a retired taxi, for reuse in another taxi, in their garage. They didn't do anything to purge the system. They ended up filling their garage with propane. They were smart enough to go outside, but when the freezer they had in the garage kicked on, it ignited the gas, and the garage was no more. The guys were relatively okay, at least.

 

[Silk]

Originally Posted By: cjcride
As Garak said cold starts are the weak point.


There was a prime button for cold starts, but CNG is lighter than air, LPG heavier. So when priming an LPG powered car, the gas fell into the carb, on CNG it went to the top...so CNG was always harder starting. Starting on petrol required forethought, switching over to petrol before you shut off, not really a problem as the carb filled pretty quickly. However, if in the morning you decided you needed petrol, you had to crank the engine over to fill the carb, draing the already marginal battery. I had a Mazda B1600 on CNG, and it had an electric fuel pump, so switching over in the morning was easy.

Before doing a conversion, we always did a cold crank vacuum test - if it couldn't pull a good signal you knew it was going to be a problem child.

 

[Garak]

Here, in my experience, we had no prime buttons. The pumps could be wired in a couple different ways; the most common was to leave the ignition on a few seconds before cranking.

-40 was very problematic unless the block heater was used.