CNG dedicated to bi-fuel?

[plenarius]

i have a 95 dodge van- and have just had my 3rd tow since may. i really like this van, but im really annoyed qt the 8 gge i can put in it-even on cold days, completely empty. the book says itll take 11 gge- lies.
ive been thinking about adding a more common fuel. and i know that their are bi-fuel cng/gas or diesel vehicles out ther- rather than buy a new van- what do i need to know in order to convert my dedicated CNG to a bi-fuel gasoline?
thanx-

[CraziFuzzy]

Re: CNG dedicated to bi-fuel?

It would be much less complicated to either add more tanks, or get a new vehicle. sorry, but there is no one making any sort of systems for doing what you are looking for.. There is also no legal backing in California for converting a vehicle to a dirtier fuel.

[freedml]

Re: CNG dedicated to bi-fuel?

It isn't the outside temperature but the heat created by expanding gas that keeps you from getting as much gas during a fast fill as a slow fill. If you wait a while you can put more in, right.

It would probably be much easier to add an emergency propane fuel supply to a 'fumigation'-type system (which I assume this is).

[larrycng]

Re: CNG dedicated to bi-fuel?

A friend of mine did that to his '95 Caravan, except he use the cng injectors already on the van. It ran great until a tranny problem made him park it. He working on that now.

Fumigation would be easier and cost about the same. You need to still consider the computer system connections assuming that you are using a feed back style system.

Larrycng

[plenarius]

Re: CNG dedicated to bi-fuel?

while i under stand heat of compression, i am by no means an auto mechanic. i was told that this doesnt have an injector- what does fumigation mean? after the gas is decompressed it floats into the engine?
adding an LPG back-up would be easier, huh? as i said before. im noe mechanic-how would this be done.

[plenarius]

Re: CNG dedicated to bi-fuel?

[QUOTE=freedml;31926] If you wait a while you can put more in, right.

QUOTE]

i can- about .02gge-thats it. the station here stops before my guage says im full by 1/8 of a tank-giving me on a good day 7-8gal.
other stations out of town stop @ about 3200 psi-i have a "full" reading. etc.thoughmy nozle is 3000psi dedicated. so, how do i add a back up- for emergancy use?

[Lakewood90712]

Re: CNG dedicated to bi-fuel?

Some here on the board have used propane as an emergency fuel , using the same injectors , and by passing all of the cng fuel sustem to the fuel rail. I do not know if this will harm the catalist.Propane has more Carbon.

On another note. A 1995 dodge is getting close to the expire date on the original tanks, if not already . Do your tanks expire in 2009 or 2010 ?

[plenarius]

Re: CNG dedicated to bi-fuel?

2010 april- thats ok. i got a few mos.... looking into new tanks. only 1 mech. an hr away cert. to do the work- wants a "diag" first- so im postponing.- how would i bypass the cng system?

[CraziFuzzy]

Re: CNG dedicated to bi-fuel?

I'd just start saving for new tanks, if you intend to keep the vehicle. The good news is, when you replace the tanks, they will be with 3600# cylinders, while will already get you an increase in capacity without taking up more space. Honestly, though, I'd think long and hard if it's worth driving the aging van around those shiny new tanks.

[larrycng]

Re: CNG dedicated to bi-fuel?

Some here on the board have used propane as an emergency fuel , using the same injectors , and by passing all of the cng fuel sustem to the fuel rail. I do not know if this will harm the catalist.Propane has more Carbon.

On another note. A 1995 dodge is getting close to the expire date on the original tanks, if not already . Do your tanks expire in 2009 or 2010 ?

MY friend inserted a "T" just before the rail split and inserted a 3 way valve (you are on the low pressure side). You had to change the valve position manually . You also have to modify a couple of sensor readings to keep the vehicle in fuel trim (swithes and resistors)

There were no problem with the injectors. The CAT is different from gasoline (I believe more rhodium for NOx conversion - lower CO and HC levels on NG). I believe it has the original CAT, I'll check next time I talk to him.

Larrycng

[plenarius]

Re: CNG dedicated to bi-fuel?

thanx guy's- im a heat and air tech, but ive never been much into cars- this is my work van for the company im starting, so im useing "cng fleet" in marketing. i know its not much- but haveing been in a wasteful trade- and using trucks and vans that down hill get 10mpg. i wanted some thing better...but going low and getting stuck sux hard. so a more available/main stream back up fuel seams to be the neccesity- till more pumps in my area. im in 95991, ca. theres only 1 til sac or chico or woodland-thats it. while the company will grow- and ill add more vans- ill make sure to improve range on them from the start- but till i get off the ground....i need a cheap fix- im also looking into HHO. any thoughts on that? does it hurt cng or help?...so thanx for the ideas

[plenarius]

Re: CNG dedicated to bi-fuel?

I'd just start saving for new tanks, if you intend to keep the vehicle. The good news is, when you replace the tanks, they will be with 3600# cylinders, while will already get you an increase in capacity without taking up more space. Honestly, though, I'd think long and hard if it's worth driving the aging van around those shiny new tanks.

the van only had 46k mi. when i bought it in april, it now has 51k- its all logoed and cleaned up. its still in great shape. just tanks-though not used much- are expireing.