Micheal H Welker Posted July 15, 2021 Share Posted July 15, 2021 Car will start and idle if one injector conector is loose.it wil actually run on 5 cylinders and rev with throtel if i have a test light atached to one side of the conector but not the other side of the conector .both sides will light up the test light though. Even with the ignition off both wires to the injector conector will light up the test light. If i plug the conector back in it kills the engine.both wires still light up a test light. Quote Link to comment Share on other sites More sharing options...
jonbill Posted July 15, 2021 Share Posted July 15, 2021 so it runs with any 5 of 6 injectors plugged in and any 1 of 6 disconnected? or is it a specific one that has to be disconnected? Quote Link to comment Share on other sites More sharing options...
Micheal H Welker Posted July 15, 2021 Author Share Posted July 15, 2021 11 minutes ago, jonbill said: so it runs with any 5 of 6 injectors plugged in and any 1 of 6 disconnected? or is it a specific one that has to be disconnected? Quote Link to comment Share on other sites More sharing options...
Micheal H Welker Posted July 15, 2021 Author Share Posted July 15, 2021 yes with any of the six unpluged but only idles. Unless test light is on the one side then it will rev Quote Link to comment Share on other sites More sharing options...
Micheal H Welker Posted July 15, 2021 Author Share Posted July 15, 2021 is it a ground or ecu? Quote Link to comment Share on other sites More sharing options...
Micheal H Welker Posted July 15, 2021 Author Share Posted July 15, 2021 I just checked the single wire going into the ecu and it is sending a pulse. Quote Link to comment Share on other sites More sharing options...
NewZed Posted July 15, 2021 Share Posted July 15, 2021 Check your grounds, in the EFI wiring harness and at the ECU. The injectors need current flow. Might be that you have only enough to run 5 injectors at idle, and the test light provides just enough extra current to get it to rev. Bad grounds = low current. Quote Link to comment Share on other sites More sharing options...
Micheal H Welker Posted July 15, 2021 Author Share Posted July 15, 2021 I just checked the single wire going into the ecu and it is sending a pulse. Quote Link to comment Share on other sites More sharing options...
Micheal H Welker Posted July 15, 2021 Author Share Posted July 15, 2021 I'm not sure how to check the efi ground? No it does not get a ground signal to the injectors. I think the test light may be suplying the ground but it will not run wirh all pluged in and test light conected to to wire to the conector. Quote Link to comment Share on other sites More sharing options...
NewZed Posted July 15, 2021 Share Posted July 15, 2021 (edited) 14 minutes ago, Micheal H Welker said: No it does not get a ground signal to the injectors. If the engine runs there's a ground for the injectors. Use the FSM and a meter. You can't get far without doing basic electrical testing on the EFI systems. Download the FSM and the 1980 EFI guide. Use the Engine Fuel and Emissions chapter. The EFI harness has its own ground point. Test at the ECU connector. https://www.classiczcars.com/files/file/32-efi-book-1980/ https://www.classiczcars.com/files/category/14-280zx/ Edited July 15, 2021 by NewZed Quote Link to comment Share on other sites More sharing options...
Micheal H Welker Posted July 15, 2021 Author Share Posted July 15, 2021 Well you just lost meat fsm? And meter? Quote Link to comment Share on other sites More sharing options...
NewZed Posted July 15, 2021 Share Posted July 15, 2021 FSM = Factory Service Manual. Meter = electrical multimeter. Must haves for working on any EFI car. EFI = electronic fuel injection. Good luck. It's difficult at the beginning but well worth the time. https://www.instructables.com/How-to-Use-and-Choose-a-Multimeter/ Quote Link to comment Share on other sites More sharing options...
Micheal H Welker Posted July 15, 2021 Author Share Posted July 15, 2021 Well should there be constant power to the injectors even when the ignition is off? Quote Link to comment Share on other sites More sharing options...
NewZed Posted July 15, 2021 Share Posted July 15, 2021 Yes. The injectors have power when the key is on and they open when the circuit is grounded by the ECU. Both sides of the injector plugs will have power because it's a parallel circuit. Unless you measure with all six injectors unplugged. Quote Link to comment Share on other sites More sharing options...
Micheal H Welker Posted July 15, 2021 Author Share Posted July 15, 2021 But these have power when the key is off? Quote Link to comment Share on other sites More sharing options...
NewZed Posted July 15, 2021 Share Posted July 15, 2021 Sorry, is that a question or a statement? Power should be off when the key is off. Quote Link to comment Share on other sites More sharing options...
jonbill Posted July 16, 2021 Share Posted July 16, 2021 The diagram shows the injectors have +12v at all times I think; doesn't go through the switch. So: it will idle on 5, but if you try to rev it higher, it dies. correct? But, if you ground the 6th,through your test light, it will rev. correct? as @NewZed said, its probably bad earths from the ECU. Quote Link to comment Share on other sites More sharing options...
NewZed Posted July 16, 2021 Share Posted July 16, 2021 You're right. That was in the back of my mind, the question has come up before, because on the 280Z's they run it through a relay. I kind of knew it was wrong when I posted it, should have held off. Not sure why they would change to constant power wires over the engine. But, apparently, they did, they show it twice. Doesn't make sense. Continue with the 20 questions... 1982 1978 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.