Nissan Repair: 90 nissan 300zx not starting, nissan 300zx, intermittent problems

Question
I have good injectors, computer ,cas, new injector connectors, when i pull the cas and spin it only two injectors are "clicking" had them all at one point ....then herd a "buzz" noise under the dash and now only two? any ideas would be great!

Answer
Hi, sorry for the delay, I was out of town. With the engine of and the ignition key off, verify a 12V voltage on each injector's connector. The connector has 2 wires. One is for the voltage supply to the injector and the other is used by the ECM to ground the injector so it can fire. If there is no voltage reading on the supply wire, try the same test with the engine off and the ignition key on. If there's still no voltage, then we are looking at a bad wiring somewhere along the line. A qualified technician needs to run some tests to isolate the problem and intermittent problems are often hard to diagnose. In the mean time you can check and make sure that the battery retains 12.6 volts, that the charging system works properly and that all grounds are tight and clean. (Motor ground, chassis ground, electrical components grounds and battery terminals.) Even though there may be a voltage reading on the injector's wiring, a poor ground it will prevent the injector from firing. :)