Engine cutting out

[Nolan]

Hello,
I have a 2002 Ford F-150 bi-fuel. It has been cutting out going up hills and today it actualy quit while I was going up hill. This happened in the CNG mode, but it also seems to be running rough (though not as rought) with the regular also. I think I am going to take it in, but any ideas on what could cause this? I am confused because there is no check engine light or anything. I don't know if that is a good sign or a bad one. Thanks for any ideas and if anyone has experience with Utah CNG mechanics feel free to let me know. Thanks,

[jblue]

Re: Engine cutting out

The compuvalve might just need a good cleaning. Check out the thread that goes into great detail about how to do just that.

But it might need a new set of COPs and plugs since you seem to have symptoms in petrol mode.

[cnghal]

Re: Engine cutting out

Could also be the O2 sensors, they help control mixture for both CNG and gasoline.

[alliedmotors]

Re: Engine cutting out

Try cleaning the MAF sensor with an electronics cleaner. But don't use anything else. The MAF is on the air cleaner tube and regulates air/fuel mixture. A faulty sensor can cause stumbling going uphill due to lack of air flow into the cleaner box. You'd need a special t-20 "security" screw to remove the sensor from the housing. This is something highly recommended on all F series pickups.

While you're at it, check the hose going into the throttle body on the top back of engine, passenger side for leaks.

[Bender]

Re: Engine cutting out

I had this very same problem on an '01 bi-fuel truck, except it would miss on the flat as well. I paid for the very expensive tune-up (i.e. coil packs, plugs, o-rings, etc) at a reputable CNG shop. Even got the compuvalve replaced under warranty at the dealer. Worked like a charm for about 25,000 miles. Then it started happening all over again just like before.

Finally after tons of research, speaking with mechanics, other F-150/250 owners I figured out the fix. I bought a Honda Civic GX.