Can some1 plz tell me how to troubleshoot a compuvalve for a 96 ford f150 bifuel trk?

[cng]

??????????

[maxman]

Re: Can some1 plz tell me how to troubleshoot a compuvalve for a 96 ford f150 bifuel

There are many ways to check it, including using a scanner. First, be sure the tank is full. I don't know how similar the 96 system is to a 2001, but mine has a fuse board with a couple fuses. If your gasoline is working, at least one of the fuses has to be good because the power that runs the fuel pump also runs part of the CNG system. Do you have a anlternate fuel switch? The later F150's have the switch near the steering wheel on the left side. If the CNG tanks are full, and the switch is in the ALT mode, but there is no green light, it is probably a problem in the Compuvalve, if yours has a GFI system.
I took the connector to the tank solenoid off and put voltage to it to hear the click showing if the valve was working. Check the coalescent filter drain to see if it has pressure there.(Make sure the key is off) I bled the pressure out of the line using the drain on the filter cannister. I then put voltage on the tank valve for a few seconds. Then check the line again at the filter canister to see if the pressure has returned. If the pressure returns, then the solenoid is working. Turn the key on with the switch in the ALT position and check for voltage at the connector which goes to the tank valve.
Actually, the best way to check the controller (compuvalve) is with a scanner. You may need to take it to a dealer or CNG service place to scan. That will be the best way.
Good Luck.

[cng]

Re: Can some1 plz tell me how to troubleshoot a compuvalve for a 96 ford f150 bifuel

Thanks Maxman. Yes it does have the Alt Fuel Switch to the left of steering wheel. I'm not really sure whats wrong with the CNG system because sometimes it works and sometimes it doesnt --- almost all the time it doesnt, and if/when it does its usually only for a few miles. Also, sometimes the Alt Fuel Switch blinks 1-long and 2-short times in succession.

Whenever i turn the ignition switch to the on position then i do hear a click sound like a solenoid being engaged. The gasoline side runs great, and the CNG tanks are full (which is also confirmed by the fuel level gage whenever it does decide to operate in CNG mode).

[maxman]

Re: Can some1 plz tell me how to troubleshoot a compuvalve for a 96 ford f150 bifuel

I spent hours and hours trying to figure mine out. When I first got my truck, the green light wasn't on. I figured it just meant it was out of CNG. Where I bought it didn't have CNG available, to my knowledge.
When I got home and tried to fill tank it was full. On mine, someone had added two hour meters, one for cng and one for gasoline. The one for gasoline had over 2000 hours on it, the cng none. That lead me to believe it has something to do with the meters being installed. I found that the meters ran off the fuel switching relay and they had apparently unplugged the Compuvalve to put the switching relay for the gauges in. Two of the plug connectors to the compuvalve had been switched and I am guessing that damaged the compuvalve. I finally took it to someplace who tested it for about $80. I ended up needing a new compuvavle which I had installed by a Ford dealer's CNG tech who was willing to do it on the side. My truck runs great now, but it was major frustration trying to troubleshoot it.
Where yours worked intermittently, I would would guess you have a bad sensor somewhere or something plugged. Look to see if the little vacuum hose on the back of the compuvalve has come off. It's a vacuum hose no thicker than a pencil. It plugs into the rear of the compuvalve on the edge near the back corner. you need a mirror on mine to see it. Also, wiggle the connectors to be sure they are all secure.
Max

[jgw50]

Re: Can some1 plz tell me how to troubleshoot a compuvalve for a 96 ford f150 bifuel

I've got 2 used compuvalves one from a 98 F150 7700, and one from a 2001 F250. $400 a piece.

[gm50cal]

Re: Can some1 plz tell me how to troubleshoot a compuvalve for a 96 ford f150 bifuel

Ive been looking at a few on ebay. is there a way to see if compuvalves are good/bad with out them being int he truck??