Hello,

I have a 96 Taurus Wagon, 3.0 OHV with 74,000 miles. Check engine light sometimes flashes, sometime just on. Code PO301. Troubleshooting has found that #1 cylinder injector is not clicking. What I mean by this is, if I put a screwdriver on any of the other injectors while the engine is idiling, I can hear a distinctive "cliking" sound whith my ear on the handle of the screwdriver. But for #1, I hear no clicking. In fact, it appears to be a "hissing" sound. I am guessing that means the injector is always spraying, thus overly rich, and misfiring. The engine does appear to run smoother at higher speeds. (25 MPH or higher, 1500 RPM or higher). My guess is that either the injector is bad, bad connection to the injector, which I doubt, or the PCM (computer), since the signal for the injector comes straight from the computer to the injector connector. Before I take the car in, have I missed anything? Oh yes, if I reset the code, the code will re-appear after about a 5 mile drive, or after warm-up. Good spark, good plugs, good compression.

Thanks

Have you pulled the spark plug for cylinder #1 to see if it is wet with fuel? How about trying a noid light to see if it's getting the proper signal. If the plug is not wet with fuel, I'd be hesitant to say the injector is stuck open.

-Rod

Rod,

I have taken the plug out of #1, and it did not appear wet, in fact it was very clean, in fact maybe too clean, as the white insulater above the spark-gap was very white! But not hot. Not a hint of tan or brown. It did not appear wet.
I have yet to try a noid light as the connector is hard to get at. To get to it, I may have to remove the upper intake manifold, which reqiures a special tool to remove the fuel lines from the fuel rail.:uhoh: Thanks for the idea! If and when I get this fixed, I will post the answer(s)!

Update: Took the car in to a reccomended local mechanic. He agreed with my diagnosis,:grinyes: but he wanted to test the signal (noid light test). The signal to the injector was good, so the next check was to check the resistance of the coil that is in the injector. The coil tested open. Some mechanics would say that the coil was "shorted-out" but actually that is not true. A good coil reads almost like a short..very few ohms. So the repair including the diagnostic test, new injector, coolant(possibly), intake manifold gasket and labor is about $350.:rolleyes:

Update #2,

Found out what killed the injector. There is a cooling pipe that runs inder the top half of the intake manifold. It had a small leak. This leaked coolant right onto the injector and eventually killed the injectors coil.:banghead: That probably explains why the insultor above the spark gap on that plug was so clean. It was probably getting "steam cleaned" while I drove. This may also be the reason that I kept getting intermittent PO136's.:nono:

Sounds like some good investigative work on the parts of you and your technician. Good job, and thank you for the excellent updates. I'm sure those will prove useful to others in the future. I hope this repair takes care of your codes and keeps you happily on the road!

-Rod