240ADAM Posted October 23, 2009 Report Share Posted October 23, 2009 I think Benzo is right, there is a fuel pump and a FI relay under your dash by the steering colum. Check those out with a relay tester or bang on them. I know my fuel pump relay on my 75 would get stuck on and drain my battery, so I beat on it a little and it was fine. My Z started dying like your does ,but I never figured it out I just did a turbo swap and that fixed it. Good luck! Quote Link to comment
Z_Rac3r Posted October 25, 2009 Author Report Share Posted October 25, 2009 I changed the coil (thanks hugh) and it ran fine to work, and back, then died yesterday morning, same problem just wouldnt start when I came back out. Rob helped me tow it home and Grr.. I know its not the relay to the ful pump because when its dead (having the issue, and not starting) you can hear the pump turn on. I'm going to try finding a new dizzy (incase its the sensor) and other then that just check the connections you guys have mentioned. :( I'm really at a loss with this one, my forte is Mechanical, not electrical ecu stuff. Thanks for all the suggestions. Quote Link to comment
DISLEXICDIME Posted October 25, 2009 Report Share Posted October 25, 2009 what about the module for the distributor have you checked that yet Quote Link to comment
hughdogz Posted October 25, 2009 Report Share Posted October 25, 2009 ^^ That's what I was thinking. You could borrow the E12-80 ignition module off my parts car, or just the whole distributor if you want. Maybe Reuel has some spares lying around... Quote Link to comment
Z_Rac3r Posted November 9, 2009 Author Report Share Posted November 9, 2009 does anyone know the part number of the ignition module on a ZX, and on a 280z? I've changed the following. Fuel Filter, Coil, Distributor, Fuel Pressure Reg, ECU, ignition module (i think its the wrong one tho), Fuel Injection Relay... all the connections in the motor have been cleaned and I put that gooey electrical connection cleaner/enhancer stuff (looks like neosporin for electronics lol) in all the connections. when its dead it get spark, so Its a fuel/air issue as far as I know.. Its not even starting now. Next time I get some daylight when I'm not at work i'm going to pull an injector and see if its squirting when I try to start it. When we put in the new ECU... it ran so awesome, drove around the block 3 times, then parked it, shut her off, and she won't start :mellow: the misfire was gone though lol... :lol::( Any ideas are appreciated. Quote Link to comment
yello620 Posted November 9, 2009 Report Share Posted November 9, 2009 Proper fuel pressure for the injectors to fire? Not- the pump comes on either. What is the pressure at with a guage? Is it in spec? If it is too low the injectors will not fire.:( Quote Link to comment
Z_Rac3r Posted November 9, 2009 Author Report Share Posted November 9, 2009 what would hold the pressure back, I'll have to get a pressure gauge to test it, but theoretically if it was low, would that mean the pump is going bad? or maybe cloggged? and why would it run perfectly normal off and on if so? Quote Link to comment
benzo Posted November 9, 2009 Report Share Posted November 9, 2009 was the relay you changed new? I assume the ecu was used. maybe the you got is bad? If the relay was used maybe that one was bad also. Quote Link to comment
Z_Rac3r Posted November 9, 2009 Author Report Share Posted November 9, 2009 Yeah it was used. :( Quote Link to comment
Cuts metal like mad Posted November 9, 2009 Report Share Posted November 9, 2009 bad electrical connections... these are a bitch to track down. You just have to go through every piece of wire that is part of the fuel system. This is a good possibility... not a certainty however. Try testing the resistence in the wires first. Quote Link to comment
Cuts metal like mad Posted November 9, 2009 Report Share Posted November 9, 2009 Why hasn't Skib fixed this yet? Is he really gonna let shit go down like this? Help the lady out, get her back on the road... Quote Link to comment
Skib Posted November 9, 2009 Report Share Posted November 9, 2009 Why hasn't Skib fixed this yet? Is he really gonna let shit go down like this? Help the lady out, get her back on the road... idk dude, this ones pissing me off :blink: weve swapped out almost everything, Im gettin to the bottom of my usable parts pile on this one :( Quote Link to comment
Z_Rac3r Posted November 9, 2009 Author Report Share Posted November 9, 2009 I just sat outside in the rain with her last night. Nothing else to do. I'm going to take a volt meter to everything I can when I get home, the only thing we haven't changed out is the temp sensor... My mechanical brain still refuses to belive an air temp sensor would control that much of the fuel, where the car won't hot start. But I'm stubborn and I've got alot of people telling me it could def. be it. :( Quote Link to comment
DanielC Posted November 9, 2009 Report Share Posted November 9, 2009 Are you sure the ignition system is working good enough to run the engine? I do not mean to nag, I am just trying to eliminate possibilities. Here is a picture of a spark tester I use to check out ignition systems: I have used this spark tester on everything from a lawnmower to a 1947 Willys Jeep, with points, and a six volt system, to my boat, with a Ford 351 fuel injection engine. The tester is available at Autozone, I believe for less than $5.00. These are general ideas I learned on working on another boat with the same engine as mine. You must know the fuel pressure is good. It is important you have a fuel pressure gauge hooked up when the symptom are occurring. Most electronic fuel injectors work like this. When the engine is suppose to be running, battery positive voltage is applied to one of the two wires connected to each fuel injector. The engine's computer then grounds the other side of the fuel injector, for the correct amount of time to provide enough fuel to meet the engines demand. A good way to check voltages at the fuel injector, or other sensors it to "back probe" the connector with "T" pin. You can get these pins at fabric stores. If you look at the electrical connector on an injector or sensor, there is usually a rubber gasket around the wire itself. You carefully can slide the pointy end ot the "T" pin right next to the wire, until it goes far enought to make electrical contact with the metal connector pin. Back to the boat I was working on. It did have a fuel injection problem, no voltage was getting to the relay that ran the puel pumps. Long story short, the boat engine had a 60 amp circuit breaker for everything on the engine, and there was also a 15 amp breaker just for the fuel injection system. The 15 amp breaker was suppose to directly connect to the 60 amp breaker, but somewhere in the wire harness, the connection went away. I could either remove, disassemble the harness, find the bad connection, and fix it, or I could just put a short jumper from one breaker to the other. I put in a short jumper witha 15 amp fuse, just to be safe. The boat has been running fine for the last two years. Quote Link to comment
Z_Rac3r Posted November 11, 2009 Author Report Share Posted November 11, 2009 Now the car will not even cold start. I need help at least to get it back in my driveway so I can tear it apart. I'm going to pick up a noid like today to check all of the injectors and the 2 temp sensors. Which sensor exactly is it? theres the two on the thermostat bigger sensor is the thermotime switch for cold start and the other one is for hot start? Can someone help me understand why it goes off the coolant temp to control fuel? That makes absolutely no sense to me. Theres also a "fuel injection temp sensor" Where abouts is that and what does the temp control? If anyone wants to come over and wrench, I would really appreciate it :( Quote Link to comment
Z_Rac3r Posted November 11, 2009 Author Report Share Posted November 11, 2009 Sorry I'm a newbie to fuel injection... I still hate it lol. Quote Link to comment
DanielC Posted November 11, 2009 Report Share Posted November 11, 2009 An engine needs a richer fuel air ratio to start, and to run cold. Liquid gasoline does not burn. Gasoline vapor burns. When it is cold, the engine requires a lot more fuel because some, or a lot of the gas does not vaporize until the engine and manifold get warm. I do not know all the details on the fuel injection system on your Z-car, I do not know how sophisticated it is. On later model cars, 1996 and later, the computer is pretty smart, and can self diagnose problems, and it turns on a check engine light so you get the car fixed. The computer also stores info on what sensors are going bad, or are "out of range", and it will tell you what went bad, by giving you a trouble code. An ECT (Engine Coolant Sensor) tells the computer to provide a rich fuel air ratio for start up. This is the fuel injection equivalent to pulling the choke knob on a mid sixties Datsun. In many cases, the computer will also compare values from the ECT, the intake air temperature, and how long the car has been not running, and if one sensor is giving bad values the computer will try to guess which one is bad, and run the engine with that info. I am going to guess one temp sensor on your engine is there just to run the temp gauge on the car, and the outer sensor is to give info to the engines computer. Quote Link to comment
Z_Rac3r Posted November 11, 2009 Author Report Share Posted November 11, 2009 I belive both those connectors go to the ECU... and Where is the air temp sensor located. because I can't find it, and I called NAPA to see if they have one, and he can't even find it in the computer. Is the only way to check these connectors with a noid light? Quote Link to comment
Z_Rac3r Posted November 11, 2009 Author Report Share Posted November 11, 2009 can someone please just come over and help me with this? :( Quote Link to comment
DRIVEN Posted November 11, 2009 Report Share Posted November 11, 2009 Noid light will only tell you whether or not the ECM is pulsing/firing the injectors. It won't tell you anything about the other connectors. If you have (1) injector pulse, (2) fuel pressure, (3) spark, (4) compression -- it should run. DanielC gave a pretty good explanation as to the importance and relevance of the coolant temp sensor. I hope it helped. Quote Link to comment
Z_Rac3r Posted November 11, 2009 Author Report Share Posted November 11, 2009 thank you DanielC it did help, I appreciate everyones input on this. Quote Link to comment
datsunrides Posted November 11, 2009 Report Share Posted November 11, 2009 It's been a long time since I messed with a Z FI setup, but if I remember there is a little plug thingy in the airflow meter flapper that can fall off and cause problems. Also may want to try and hold the flapper door open a little and see if it wil fire. I think the flapper has something to do with the fuel pump or injectors somehow. Worth a look. Mark Quote Link to comment
athoose Posted November 11, 2009 Report Share Posted November 11, 2009 Your should hear the pump running when the ignition is in the start position. Disconnect the wire going to the stater terminal so the engine wont be turning over as you listen. You should also hear a click coming from the ignition relay inside the car when turned on, sorry not sure where it is on the 78z. Get the 78 factory service manual and follow the troublshooting chart. It is fairly easy to test most components, If something is shot it should show up. If not you probably have some bad corrocion. you can get a 79 manual here. http://www.xenons130.com/reference.html Also get the efi bible, you can troubleshoot with it as well. Good Luck Quote Link to comment
Skib Posted November 12, 2009 Report Share Posted November 12, 2009 I do not know how sophisticated it is. Z/ZX ECU's are the equivalent of a cheap graphing calculator Quote Link to comment
FoxyRoadster Posted November 12, 2009 Report Share Posted November 12, 2009 If the car smells like its getting fuel then are the plugs firing at all? How do they look? I don't know what you've replaced on it but... Quote Link to comment
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