Hey guys, I'm trying to figure out how to remove the CNG junk off of my 'new' '99 low-mile work van. I bought a rolled '04 E250 parts van which I intend to swap all the fuel stuff from.

It appears that it's a OEM natural gas install. It's got one large torpedo tank and two smaller ones where the spare tire needs to be.

Where do I start to bleed off pressure etc?? I am excepting to have to swap, fuel lines, injectors, and gas tank setup. Is the computer the same? What about the 02 sensors etc? Thanks in advance!

 

there should be shutoffs on the tanks themselves and then only residual pressure in the lines, I don't know how to bleed the residual pressure, but thats a start, make sure the tanks are off!

 

After further inspection I think I'm just going to leave it in tact and sell it. It runs very smooth and well and has low miles. I was able to bleed off pressure on rails to heli coil a spark plug hole.

 

I am in the search to do the same thing to mine. I hope to be able to go through with it. Had you located the tank shut valves themselves?
Mine is '98 factory Ford CNG only vehicle as well.

 

The tanks are shut off when the key is off. You simply unhook them and remove. The real problem is that every single wire harness on the van is CNG specific. I had to buy a parts van and swap the entire wiring harness, fuel system, charcoal system, etc. It was a lot of work, WAY more than I had bargained for.

 

Thanks for response.
I noticed I have a 2 or 3 prong wire that is capped and attached to nothing under the hood. Been doing a lot of work on the degas bottle / rad area and noticed it fishing around and drying out some ejected 'cooloil'.
Had been wondering if that was for a stock gasoline setup.
Hmm. the whole wiring harness?? That's a lot of work.
What's the charcoal setup for? Are you in CA for emissions? Could one skip that?
(I know on my motorcycle many people opt to chop out the charcoal canister system and block off the EGR to save weight).

I just read today the Crown Vic's have a manual shut off on the tanks, and the e250 and e350 have this keyed / electronic shut valve. No ignition key in, no 12V no open valve. I am wondering though, while hooked up, sure, I guess it's not flowing CNG then. But what about when you remove the tanks from the vehicle - I guess they just electronically continue to stay shut?

I am looking at a donor vehicle buy to swap to gasoline and gut the CNG.

Is your conversion / retrofit back running? How long did it take you do this?
Did you also change out the fuel rails / injectors?
Was a computer (ECM) swap needed or use the CNG installed stock one as is? Or did you have to re-flash it?