Stock gasoline injectors used for CNG?

[CraziFuzzy]

I am curious if the 'experts' here have had any experience using stock gasoline injectors for CNG use, and if there is any detrimental effects in doing so. My late-night brainstorming is keeping me up and wondering how complicated a conversion would be using the stock in-place injectors/fuel-rail, and a multi-program ECU module. In theory, all that would need to be changed would be the fuelmaps for running on CNG (obviously a lot of testing required), and the proper regulation/switching systems to select cng to the rail, and prevent cng going back to the gas tank. Like I said, just early brainstorming, and this was the first 'hurdle' I've come to.

For info, this is for potential off-road/marine use, but don't see why it wouldn't be a workable on-road solution, keeping all obd diagnostics in place, and not 'simulating/doping' any signals.

[Franz]

Re: Stock gasoline injectors used for CNG?

1) The gasoline injectors will not flow enough through them for operation on CNG;

2) The gasoline injectors are rated at somewhere between 40 and 90 psig. Any more and there is a serious chance of blowing apart;

3) Gasoline injectors are not designed to run dry. They will overheat and burn out on CNG since there is no liquid fuel flushing them to keep them cool.

4) Gasoline injectors are not designed to run dry, thus the insides will wear, significantly altering the injector profile.

Injectors designed for gaseous fuel are expensive and hard to find. You MIGHT be able to source some from a good auto supply, from a mid 1990's Dodge CNG van or from one of the Ford CNG sequential injected vehicles, not the GFI model.

Lastly, pressure at the injector should never exceed around 100 psig, the fuel rail may lack sufficient integrity and may simply blow off the injector.

Franz

[CraziFuzzy]

Re: Stock gasoline injectors used for CNG?

Yeah, i totally intended on keeping the pressure <100 psi (I think the 5.4L runs the gasoline rail at <45psi). The dry running issue was my biggest initial concern.