Hi all,

Having a strange issue with my 1998 Discovery. A little while back, my intake manifold was leaking coolant, which got to the point where it needed replacement. Took it into my local mechanic, who I have had good luck with in the past. After, I have not been able to get the car over about 30 mph. The engine will stutter and misfire under acceleration. Originally a code was thrown for bad O2 sensor, so I replaced all four, however the problem continued with no code present. Replaced spark plugs, and spark plug wires, and finally cam shaft sensor at the recommendation of the mechanic. Did most of the work myself apart from the cam shaft sensor and the manifold gasket.

Currently the engine starts and idles fine, however when accelerating, it misfires, runs rough and has a strong gas smell from the exhaust. Any ideas as to what I could be looking at? Mechanic and I are out of ideas. Any help would be appreciated!!

 

Check for vacuum leaks. There is a small line on the fuel pressure regulator that has a bad habit of coming off.

 

Could also be a wire pinched from the harness, look carefully. Fuel temp sensor on the fuel rail comes to mind. It gets lower in resistance as temp increases, so a short would make it look like you are running so hot that computer adjusts fuel to minimum.