F-150 CNG Removing System

[Channing]

1998 F-150 I want to remove the CNG system. If I remove the apparatus under the hood. Is it easy to do? Will the truck still run? What do I need to know.

[Lancer Automotive Group]

Re: F-150 CNG Removing System

Is there a reason you would want to remove the system for your Ford? Just curious.

[Channing]

Re: F-150 CNG Removing System

The system dosen't work to start with. I have numourus problems in the valley area including a vacume leak and an ignition problem. So I want this out of my way. I tryed unpluging it and the truck won't run so there must be a plug or pigtail that needs to be reinstalled?
Plus we have no CNG in this area

[Lancer Automotive Group]

Re: F-150 CNG Removing System

What area are you in?

[Channing]

Re: F-150 CNG Removing System

North of Boston

[Lancer Automotive Group]

Re: F-150 CNG Removing System

Let me do some checking they maybe a shop that will remove it for free if they can have the used parts, let me see if I can find there number.

[CNG Utah]

Re: F-150 CNG Removing System

Does the truck still have the CNG tanks in the bed, or have they been removed?

[Rickinokc]

Re: F-150 CNG Removing System

I will take the tank-thanks

Rick

[Channing]

Re: F-150 CNG Removing System

OK OK I know everybody wants the parts. we are a gov fire dept so I cant just give the stuff away but we can have them declared surplus. I realy need someone to tell me how to make the truck run without the compuvalve and the black box.

I unpluged some of the plugs and the truck died so I stoped there. Most of the plugs are numbered if that helps.

[rtry9a]

Re: F-150 CNG Removing System

There is a common splice on your fuel pump wire from the compuvalve, other than that the systems are mostly separate and independant.

The only other parts that might give you problems I know of involve water lines and the fuel injectors- the metered nat gas feeds into rubber spacers under the normal gasoline injectors- you might be able to either block the natgas ports or replace the spacers- Dont know if you can just remove them or not.

[Channing]

Re: F-150 CNG Removing System

I just want to get the compuvalve off the top of the motor. When I dissconnect J-8, J-209,P-37 or the black box under the dash the motor races up to mid throttle and stays there.

If I dissconnect the single red wire the ties into ford harness the motor dies. Any more input would be very helpfull.

[larrycng]

Re: F-150 CNG Removing System

Let me see if I have wiring diagram for the vehicle.

Normally you would have to restore wiring to the gasoline configuration. This means finding which circuits are intercepts and removing them (taking them out of the Ford system), then you would cut tap wires. You would need the standard Ford diagram and the one for the bi-fuel system.

After all the work is done you should check the vehicle with a computer scan tool to verify all the OBD II circuits are working.

Larrycng

[CNGparts]

Re: F-150 CNG Removing System

All you have to do is disconnect the fuel pump from the CNG wiring harness and reconnect it with the original harness. It's easy to see, I don't even have to put the truck on a lift to do it. Then you have to take the two coolant lines from the regulator and connect them together. The last step is to cap the hose going from the compuvalve to the fuel rail.

[Channing]

Re: F-150 CNG Removing System

OK I see the 2 plugs hanging down next to the fuel tank. assuming there ford plugs I just plug the fuel sender into those.

So thats it? I can unplug the compuvalve and I already capped the fuel rail.
Why is the motor racing when I unplug the compuvalve.

A local mechanic says the ford computer probably needs to be reprogramed

CNG parts have you done this on a F-150 before??? Please keep the information comming Thanks everybody...

[CNGparts]

Re: F-150 CNG Removing System

I've done this to three 01 F150's. I don't touch the fuel rail at all, what I do is cut the hose coming from the front of the compuvalve as close as I can to the splitter that connects to the fuel rail and then cap it off. Once the hose is off and capped, the compuvavle should be able to come right out. The CNG basically comes in the back of the compuvalve and out the front through that hose. My guess is air is still getting sucked into the fuel system through the hose that needs to be capped.