Erratic Knocking Question

[TylerMartin]

Hey guys,



I was driving to work this morning when all of a sudden my truck started knocking erraticly and reving between 1000 and 3000 rpm. It scared the crap out of me. I pulled over and shut the truck down to have a look under the hood. Everything looked normal (ie: no leaking fluids or disconnected hoses). I checked the trouble code and it gave a code of P0236. I restarted the engine and it has ran totally normal for the rest of the day.



What could have caused this? Is it injectors, fuel pump, or what? I work in pretty remote areas and I can't afford to wait until something causes permanent damage and leaves me stranded. This has been a great truck and I've never had any problems with it other than a wire on the back of the radiator rubbing through and a hole in my aluminum rim. The truck has 95000 km's.



Any help is appreciated. Thanks.

 

[RAMINSPEED]

Check all of the wire connections under the hood, especially the one for the fuel system.

 

[JCleary]

Unplug the Quad Race harness completely and see how your truck runs.



My truck would do weird things with the harness in place, even with the bypass plug installed instead of the box. Rough idle, surging, stumbling, etc. The throttle wouldn't respond so I would give it more, and the truck would catch and take off. I thought I couldn't drive a clutch any more, I felt like an idiot.



I uninstalled the harness and the truck runs great since.



Some have had success with using dielectric grease on the MAP and Rail plugs when experiencing these same problems, but I am not going to do that. It's a perfect way for a tech to see you've tampered with your truck.



Even if you remove and reinstall each plug, you should have a better connection.

 

[TylerMartin]

You think it has to do with the Quad box? I've had it installed on my truck for over a year and never had any problems with it (mind you I hardly ever have it turned on). I unplugged my connections and had a look. There didn't seem to be anything out of the ordinary. I left it unplugged completely and drove it for a while. It seems exactly the same as when it's plugged in.



I guess I'll have to wait until it acts up again.



Thanks