jas280z Posted July 3, 2010 Share Posted July 3, 2010 Tried to start my 280z yesterday to move it in the garage, started right up, but then died immediately. Tried to restart, but noticed that the fuel pressure gauge in the engine bay wasn't showing any pressure. Looked at the gas guage and noticed that it wasn't showing anything, the needle never even went up to E. Got under the car and tried to start it and the fuel pump wasn't turning on. Tried the headlights, they didn't work, but the running lights came on. Hazards worked, but no turn signals. Voltmeter in the car showed 14 volts. Today, while trying to diagnose the problem, the problem got worse to the point where the car has not power what so ever. The car had power, I pulled the fusible link covers, looked at them, and put some di-electric connectors between the fusable links and battery, which I think are fuel pump relays. After I did this the car had no power at all. I pulled the connections back off and checked them, and they all looked fine. When I pull the negative cable from the battery and put it back on there is not very minimal sparking, and you can hear a couple clicks in the car, sounds like they are under the dashboard, but there is still no voltage. The only changes I have made since the last time it ran fine is a new differential mount insulator and currently redoing the front suspension. One other thing of note is that the headlights occasionally wouldn't turn on, but they would always turn on with the next try. I am going through the wiring diagram in the FSM, trying to figure out what the problem could be, but I was wondering if anyone had any suggestions. Thanks. Quote Link to comment Share on other sites More sharing options...
jas280z Posted July 4, 2010 Author Share Posted July 4, 2010 Fixed the problem by removing and cleaning the connections at the fusible links, fuel pump relays, and ignition relays. Don't know which of these was causing the problem, may have been a combination, but it is better now. Quote Link to comment Share on other sites More sharing options...
SmoothZ Posted July 4, 2010 Share Posted July 4, 2010 Sorry for the noob question, but what did you use to clean those parts? I have the same problem. I just picked up my 260 and have to jump start it each time. One of the fusible links is fried, so I'm sure that's a problem. I'm looking at upgrading that anyway. For now, I'd like to clean up the connections and what not. Thanks. Quote Link to comment Share on other sites More sharing options...
jas280z Posted July 4, 2010 Author Share Posted July 4, 2010 Just some dielectric grease and a brush to get any corrosion off. Quote Link to comment Share on other sites More sharing options...
Austin240Z Posted July 7, 2010 Share Posted July 7, 2010 (edited) Since you're having a series of electrical problems, start with the source, the battery. If your battery is a year and a half to 3 years old, take it to the local parts house and they can check it for free. Bad batteries cause 50-75% of electrical problems (usually on newer cars though) and most people dont bother to have it checked. A battery with a dead cell will act like someone severed your battery connections intermittently, and can cause literally all the problems you have described. Also check the main cable connections at the battery, and where the attach to the starter and engine block. If they're rusty, broken or corroded, replace them. Once that is eliminated, check the alternator and voltage regulator connections. Just because the interior gauges show 14 volts, doesn't mean that's actually what you are getting. The S30 volt gauges aren't exactly reliable, especially after 30 years. (have a buddy who's gauges read 15-17 volts, but alternator puts out approx 14 when checked with the alternator tester) In addition, the fuseable links a very common source of problems, which it seems like you are already aware of. I had a fuseable link with a broken connector and the headlights stopped working, but running lights still worked. Fixed the connector and everything worked properly again. Just because they look ok, doesn't mean they are, however I would be surprised to see them all fail at once unless your alternator was putting out upwards of 15 volts. Your gauges are run off of the main harness rather than the ECU harness, so in my personal opinion, I think you either have a battery problem, an issue with a main power or ground cable, or Maybe the connections for the main harness under the passenger side of the dash.... but if you are able to get your main electrical power back, and the fuel system still isnt working, then you may have additional problems in the Fuel Injection side harness. The fuel pump and injectors run off a single relay, which the Bosch FI manual suggests checking in pretty much every diagnostic procedure, mine does not work, they are available from most parts stores for around $120, but since that's a lot of money and I hate wiring issues, I just dumped the FI entirely and went to a pair of round top SU's. Also check your ECU connection as I have noticed that on about 4 or 5 280Z's here from our Local Z club, the clips that hold the main ECU connection on have stretched slightly over the last 30 years causing a slightly loose connection resulting in a whole slew of problems. The most common problem being complete loss of (horse)power after reaching normal operating temperature on a hot texas summer day, this includes the vehicle stalling out completely and not being able to start back up until the connections have cooled down (usually 10-15 minutes) Edited July 7, 2010 by Austin240Z Quote Link to comment Share on other sites More sharing options...
DCZ Posted July 7, 2010 Share Posted July 7, 2010 When my gauges recently went dead (73 240z) I cleaned the connections under the steering column (ignition switch, turn signal switch, headlight switch) and that fixed the problem. Quote Link to comment Share on other sites More sharing options...
Pharaohabq Posted July 7, 2010 Share Posted July 7, 2010 YEah I've had the fusible links cause trouble so many times. It's a really good idea to replace them. though cleaning the connections usually help since 30+ years of weathering can really corrode the metal. At radio shack or Autozone or other local auto parts places they should have electrical connection cleaner. This along with some dielectric great will solve tons of issues. eg Injector plug connectors, fusible links, AFM plug. Thermotime plug. all should be cleaned. You can also buy replacement rubber boot connectors cheap on Ebay to help keep the bad water out of the plugs. Corroded connectors not only don't work right, but they generate resistance which makes heat, which if left alone can cause harness shorts or ever a fire, so keep that in mind when you're seeing corrosion on a plug. Phar Quote Link to comment Share on other sites More sharing options...
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