DavidZ1911 Posted February 7, 2015 Share Posted February 7, 2015 hello all, I am new here. I have searched and searched for an answer to my problem. I got my 1978 280Z home yesterday, I drove it for 200 miles to get it home and it was PERFECT. Started up like a new car each and every time. Woke up this morning and took the car out, all was fine but I noticed it seemed like it had a small miss down low. Went to surprise my dad with the car, It died on me on the way there while I was in mid acceleration. It started right back up no problem at all. Got to my parents, turned it off showed my dad, started it right back up drove my dad down the road, went to take off from 1st and it died. I started it back up and all was well. drove my dad back, turned it off and talked for 20-30 minutes, went to leave and now it wont start at all. I pulled the fuel pump and blew through it perfectly fine, no restriction at all, Pulled the line before the filter and then after the filter and tried to start the car, gas flooded everywhere like opening a water tap. hooked it all back up and the car just wont start. I did notice that the fuel pump NEVER shuts off. Its always running while the key is on or trying to crank it. If anyone has any tips I would greatly appreciate the help. Thanks. Quote Link to comment Share on other sites More sharing options...
Miles Posted February 7, 2015 Share Posted February 7, 2015 You will need to consult the factory service manual (FSM). Look in the downloads forum for Xenon where you can find a pdf of your specific FSM. Quote Link to comment Share on other sites More sharing options...
NewZed Posted February 7, 2015 Share Posted February 7, 2015 There's a problem-solving principle known as "first principles". Go to the basics. Spark, fuel, timing, etc. Check for spark. Then get all Boolean on it. Quote Link to comment Share on other sites More sharing options...
DavidZ1911 Posted February 7, 2015 Author Share Posted February 7, 2015 Thanks for the replies. Miles-Thanks for the info, I actually downloaded the FSM right after posting this. Newzed- Yea I am going through the basics. I was about hot when i was typing the original post out bc it was rather annoying that I can drive 200 miles without a problem at all, and i go to give the car to my dad, as it was a surprise gift for him, and then this happens and i was really just looking for a good starting place beyond the basics as i have confirmed they are all good. which adds to the frustration. I shall reply back once i have it figured out. Quote Link to comment Share on other sites More sharing options...
jeremy93ls Posted February 7, 2015 Share Posted February 7, 2015 At least on a 78, the fuel pump shouldn't run constantly with the key on like that. It's trying to build enough pressure in the system. My 78 with a new OEM pump will run the pump to pressurize the lines if it's been sitting a while just before I turn the engine over. I have a leaky injector (or two) and it hums until the pressure builds up. Maybe there's a leak somewhere in the lines that keep it from reaching enough pressure? I recommend a gauge after the fuel filter under the hood. It will help you solve fuel delivery issues. I can watch the pressure build on an inline gauge from inside the car with the hood up. Quote Link to comment Share on other sites More sharing options...
NewZed Posted February 7, 2015 Share Posted February 7, 2015 just looking for a good starting place beyond the basics as i have confirmed they are all good. If they were "all good" the engine would start. Therefore, at least one is not good. The quick test for EFI is starting fluid. If the engine starts, there's a fuel supply problem. If it doesn't, probably a spark problem, Assuming nothing major, like holes in pistons. Typically, a random number things will be examined in random order until something is found, Best to test a specific set of things in a specific order. Quote Link to comment Share on other sites More sharing options...
DavidZ1911 Posted February 8, 2015 Author Share Posted February 8, 2015 Thank you for the words of wisdom. Well I'm a bit stumped on this. I called it quits last night and figured a saner mind would prevail. So today I went back to my parents where the car was sitting. I tried to start it and it would fire, then immediately die. No matter how many times I tried, same thing fire then die almost as soon as it fired off. So I ran back through spark,fuel and air. I wasn't getting any spark from the coil. So I thought what the hell how did I miss this. Replaced and still fired and then died. So I pulled the intake tube off, sprayed some starting fluid in there while my dad cranked it. It fired off and ran until we pressed the throttle. Started it again with the fluid 2-3 more times and same thing happened. On the 4th tried it fired and kept running perfectly just like when I picked it up from buying it. And it's been perfectly fine since then. I will say that my fuel pump never turns off when In the ON position, so I'm assuming a relay is stuck? Also it still sounds like it has a miss or something. The exhaust in the back sounds very lopey like a car with an upgraded cam would sound. so I'm not really sure why exactly was wrong with it and why it works fine now when nothing was replaced other than the coil. Which like I said did nothing until the fluid was sprayed in it. Quote Link to comment Share on other sites More sharing options...
DavidZ1911 Posted February 8, 2015 Author Share Posted February 8, 2015 ok so car was running fine. it has spark and it has air. the fuel pump is pumping and the pressure is correct. I sprayed starter fluid in the throttle body, car runs and immediately dies. I am thinking it is the injectors. Does anyone else Have any opinion that might help me? I am about to go through the injector testing process, unfortunately no one in my area has any in stock and it will be a week before i can get new ones. Is there a way to clean the injectors and re-use them or am i just sol if they aren't spraying? Quote Link to comment Share on other sites More sharing options...
NewZed Posted February 9, 2015 Share Posted February 9, 2015 (edited) You're not going to have 6 injectors go bad at the same time. It's not your injectors. Check for power to the injectors first. Does the tachometer work? Is the resistor in place on the blue wire to the tach? Is there power to the ECU? Check for power to the places that need power. The EFI (injection) system is separate from the ignition system, but it does use the coil negative terminal to determine when to inject. Search on "Pin 1". Don't forget to confirm power to the fuel pump also. There's a fuel pump control relay on the 78's that uses one of two possible signals to keep power on. Described in Engine Fuel chapter, I believe. Along with a bunch of tests. Also, try to keep your logic straight. You're mixing some things up that just can't be, like engine starting with no spark. Only diesels do that. "it would fire, then immediately die. No matter how many times I tried, same thing fire then die almost as soon as it fired off. So I ran back through spark,fuel and air. I wasn't getting any spark from the coil. " Edited February 9, 2015 by NewZed Quote Link to comment Share on other sites More sharing options...
DavidZ1911 Posted February 9, 2015 Author Share Posted February 9, 2015 You are correct, I apologize for that idiocy on my part just due to frustration. I did not neccesarily mean all 6 of the injectors were faulty at the same time, simply that i believe they are not working as they should and that i do not believe it is the pump as it has power, fuel pressure is in spec between the filter and the rail, I will be testing the power to all the efi components tomorrow. Quote Link to comment Share on other sites More sharing options...
C.RyanStephens Posted March 7, 2015 Share Posted March 7, 2015 my car did something similar, i too have a 78 280z, when its running, wiggle the harnedd to the Fuel injection control module, its to the left of your left foot while sitting in the drivers seat. i had a loose wire going into the module that went to my AFM, i also had a tank full of rust which isnt too uncommon in these z cars, under the deck of the rear hatch there is an inspection lid with your fuel sending unit in it, undo the lock ring (it may be stuck, but it turns counterclockwise, use a screw driver rested on the ridge of one of the little locking things and ta the end till it spins) take a dowel or a long rod and drag the tip of it across the bottom of the tank, see how much crud is built up down there. it was clogging my fuel lines, the fuel pressure was fine sometimes then other time it was god awful. fixed my issues Quote Link to comment Share on other sites More sharing options...
Pac_Man Posted March 8, 2015 Share Posted March 8, 2015 I'd say hook in a fuel pressure gauge and make the hose long enough to tape it to your windshield. Get it to run normally and look at fuel pressure. Drive it down the road or whatever you need to do in order to get it to run like crap. If fuel pressure drops, then your issue likely lies somewhere in clogged lines or a pump that is going bad. Is the pump OEM? Ever been replaced? When my fuel pump started to go bad it would randomly make the car cut out for a few seconds like the engine shut off and then pick back up again. Eventually it would die while I was driving around town and I'd have to give it a few tries to restart it. Got worse and more frequent in the course of a few months. Quote Link to comment Share on other sites More sharing options...
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