Hi All,

Took my car for a spin. Always inspect it idling post drive and look for issues. Inspected injector electrical connections and observed that engine would run rough when all injector plugs individually removed for all cylinders except no. 4. When I pull that connector no change in idle. I suspect injector is dead or not receiving power.

Do I check voltage at injector plug then pull injector and put 9V on it? Any advice welcome. Bone stock D-jet. Thanks in advance.

Reg

A noid light on the injector connector should indicate pulse if thats the problem. Odd for the electrical on only one cyl to go down and not a pair.

Squirt the injector into a jar to check for flow. Or just send them all out for maintenance cleaning.

You might also check for any broken or suspect ground wires at the FI harness ground connection on the engine case.

switch the leads front to rear and see if the dead cylinder moves or stays at no 4. If it stays, check the valve adjust and compression. If it moves then suspect a bad ground lead at the back of the block OR a bad injector (not likely). Also check for spark. No 4 is the notorious cylinder to fail first as it is the hottest

Thanks gentlemen. Off to the garage. Will report back.

Turns out spark plug ok, injector functions ok but wiring harness plug did not snugly fit in injector receptacle. Not sure why. Replaced with another injector and plug fit more snug and definitely have running cylinder now. Thanks all for the help.

Best, Reg

This is a good job for an IR temp gun.