Joined: Mar 2005
Location: New Cumberland, PA
I had the exact same thing in my 94 LE that had about 213,000 miles on it at the time. I currently have 219,000 on it. anyway, it had a really bad misfire and vibration, but at highway speeds, it seemed to smooth itself out. also, when I had it in drive and I was stopped at a light, it had a rough vibration too. and the drivability problem happened basically overnight. one trip, everything was fine. next trip, I had the vibration problems. after swapping the plugs, wires, cap, rotor, ECU, and entire distributor with known good ones from my other sentra, a 94 XE, I narrowed the problem down to a bad fuel injector. it was the #4 injector, the one all the way over to the drivers side.
there are 3 ways to check injectors. the easiest is to get a screwdriver or a long socket extension. start the engine, put one end of the screwdriver to your ear and the other end to each fuel injector. this is a really simplified stethoscope. you should hear a distinct "click" from each injector, in a pretty consistent pattern.
a better way is to start the engine and one by one, disconnect and reconnect the harnesses for the fuel injectors. each one has a 2-wire harness on it. disconnecting it meant pressing on a tab first. disconnect one injector harness. the engine should stumble and run worse. that means the injector was working. if nothing happens, that could be the faulty injector. plug that injector back in before moving to the next one. I did this test when I had the misfire problem. the first 3 injectors caused a reaction, and the 4th didn't. that's how I knew.
and finally, if you think you have a faulty injector, it can be verified with an ohmmeter. with the engine off, disconnect the harness to the injector that might be bad, and touch the ohmmeter probes to the pins on the injector. a good injector should measure 10 ohms I think. my faulty one read 0 ohms.
it was about a 2 hour job, I ended up having to get a new injector (about $70) and a new intake collector gasket ($5 from nissan). new injector fixed it, and even fixed the rough idle I had when I was stopped at the light.
but I'd start with the basics first, plugs, wires, cap, rotor, stuff like that. just because you have 33,000 original miles doesn't mean you don't need to worry about a tuneup. change that stuff out with new parts and see where that gets you. but if you tune everything up and still have the problem, I'd lay money on you needing a new fuel injector. it sounds like you have the exact same symptoms I did.
"if you aren't really shifting, you aren't really driving."
Last edited by blackmaxima88; Oct 18th, 2005 at 03:14 PM.