Sneze Posted March 16, 2014 Share Posted March 16, 2014 (edited) Hello people First of all, it's an sr20 in a '78 280z in which my brother and I did everything except the wiring which was done by a shop (with a new "Painless" wiring harness). Right, so earlier this week the car died on the way home so we towed it home and found out the fuel pump was not working because it was not getting power. With some tests with a multimeter, we concluded the wire is broken somewhere in the harness. Instead of following the wire through the maze of the harness to find the problem, I wired the pump directly to the battery, with a toggle switch, and the pump definitely works as it makes a sound. But it still wont start. It cranks fine, the fuel tank is full, but it wont fire. What could be wrong? Is it not ok to wire the fuel pump directly to the battery? Is the problem somewhere other than the fuel system? Thanks! Edited March 16, 2014 by Sneze Quote Link to comment Share on other sites More sharing options...
NewZed Posted March 16, 2014 Share Posted March 16, 2014 Whatever failed probably powered both the fuel pump and something else. The something else still needs power. Maybe the ignition system. Quote Link to comment Share on other sites More sharing options...
dexter72 Posted March 16, 2014 Share Posted March 16, 2014 Have you checked for fuel flow, from the hose connected to the fuel rail??.. You could have a clogged tank, filter, or line. Have you checked for spark at the spark plugs??.. Have you checked all the fuses??.. I think you have more things to check. You can wire the fuel pump like you have but you should always have an inline fuse installed also. Quote Link to comment Share on other sites More sharing options...
Sneze Posted March 16, 2014 Author Share Posted March 16, 2014 Thanks for the suggestion of checking the spark! We didnt see a reason why the spark plugs would stop working but after your suggestion we went ahead and checked. Alas, we have no spark. Does anyone know what could have happened to make the fuel pump not get any power AND the spark plugs? We checked fuel flow, and its totally fine. Quickly checked all the fuses but would a blown fuse be the problem? If so we can check them even harder. Quote Link to comment Share on other sites More sharing options...
NewZed Posted March 16, 2014 Share Posted March 16, 2014 Take the multimeter you used to check the wire, turn the knob to DC voltage, and check for power on the ignition circuit. The coil (or coils, depending on ignition setup) is a good place to start. Describing the ignition system and EMS you're using would help people give you some better guesses. It's not a 1978 280Z anymore. Quote Link to comment Share on other sites More sharing options...
dexter72 Posted March 16, 2014 Share Posted March 16, 2014 When checking any no-start while the engine turns over condition, always check for spark, air, and fuel. Always check your fuses and fuse links for power, always check for fuel flow and pressure. And i say fuel flow because a fuel pump can pump air pressure and wont be pumping. Check for proper voltage at your fuse links and fuses with the key on and then with the key in the starting/cranking position. You should find out how that wiring harness is wired for the engine components. Did you get a wiring diagram with the harness that was installed??... Thats if it was an aftermarket harness. Possible ignitor failure, wiring failure, ecu or ecm issue, Aftermarket stand alone component issue. Like what was mentioned above, Does the car have an aftermarket ignition system, Factory ecu wiring, Aftermarket ecu???.. Quote Link to comment Share on other sites More sharing options...
Sneze Posted March 16, 2014 Author Share Posted March 16, 2014 Right, so everything is stock except the wiring harness which was professionally installed. No standalone, just factory ecu, and stock coil over plugs. It looks like this problem is getting specific to the engine (sr20) so i think ill have to look at forums with topics on sr20's not getting a spark. There are already a lot of other posts with seemingly the same problem i have. Most are talking about coils not working, bad wiring, or broken ignitor chips. Buuuut if anyone knows what could have happened to make a perfectly running car all of a sudden get no power to the fuel pump AND get no spark, im all ears. Also ill talk to the guy who wired it up for us and see if he has any ideas. Quote Link to comment Share on other sites More sharing options...
dexter72 Posted March 16, 2014 Share Posted March 16, 2014 Electrical parts fail or go bad sometimes, thats just how things go. As long as the same part doesn't keep failing real quick, i wouldn't be too alarmed. You didn't say yet if you checked all the fuses for power, So do that before starting to replace parts. Next find the steps to diagnose the ignitor, Check power to the cas and see if it is bad. Quote Link to comment Share on other sites More sharing options...
Sneze Posted March 21, 2014 Author Share Posted March 21, 2014 It's fixed! You were totoally right, dexter. We had the guy who wired it up to check the car and one of the big 80A fuses mounted in the engine bay blew. I checked that same fuse before but i guess i didnt look at it hard enough. Thanks for the help and replies everyone Quote Link to comment Share on other sites More sharing options...
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