9rider Posted May 7, 2013 Author Share Posted May 7, 2013 er, I edit a bigger picture. Quote Link to comment Share on other sites More sharing options...
9rider Posted May 7, 2013 Author Share Posted May 7, 2013 (edited) I don't have noid light to check injector pulse. Need to buy one. Is there anyway to check if my ECU in working condition without getting a second ECU to test it? Edited May 7, 2013 by 9rider Quote Link to comment Share on other sites More sharing options...
Domzs Posted May 8, 2013 Share Posted May 8, 2013 Don't think there's a way to check the ECM . All you can do is to test all powers , grounds , and inputs . If everything checked out good then you condemned the ECM . Noid light is pretty cheap , you can get one for Bosch style connector or the whole kit . Or you can make it one by using a low amp light bulb . Quote Link to comment Share on other sites More sharing options...
4.6StangRage Posted May 8, 2013 Share Posted May 8, 2013 (edited) Here are the connectors under the dash. The ones that are using the Weather pack connection is the one that controls injector pulsing. Definitely go to the single connector, which will be a small square connector on yours (assuming that you have a '77) and check for pulsing on the Blue colored wire. Use a test light and probe it while cranking to see if there is a pulse. If you don't have a pulse your problem lies within this circuit. Also, did you try checking the resistance on your injectors? A shorted out injector will definitely cause your ECU to not fire the other injectors. Edited May 8, 2013 by 4.6StangRage Quote Link to comment Share on other sites More sharing options...
9rider Posted May 8, 2013 Author Share Posted May 8, 2013 @4.6StangRage: my Z is 1976 but I think those wires would be same from 76 to 78 ( dont know about the turbo one) I did check the circuit for injector using the ECU plugs pins. All of them showed same value and continuous . Didn't check resistance of each in the engine bay yet. If so, what is the resistance's value of each injector. I traced almost all the wires from the ECU to engine bay and to each sensor, double check if anything lose but everything was fine. Took the dropping resistor apart and test resistance show 10.4 ohm equally across all 6 resistors.( dont know if this right value, I am using cheap FREE multimeter from harbor freight) Quote Link to comment Share on other sites More sharing options...
9rider Posted May 8, 2013 Author Share Posted May 8, 2013 Does anybody know where is the transistor ignition unit located? Is it on the pass side under dash? Thanks Quote Link to comment Share on other sites More sharing options...
NewZed Posted May 8, 2013 Share Posted May 8, 2013 The ignition module is above and forward of the fuse box. About 5" x 5" dark green box. Resistance values for the dropping resistors are shown on page EF-56. Most of your testing can be done right at the ECU connector. Look through the FSM to find the right value, look at the wiring diagram to see what pins tocheck at the connector. The connector is the best place to start since what the ECU sees is what's important. 76 and 78 have some differences in wiring at the igntion module and at some of the relays. Quote Link to comment Share on other sites More sharing options...
Domzs Posted May 8, 2013 Share Posted May 8, 2013 Does anybody know where is the transistor ignition unit located? Is it on the pass side under dash? ThanksIf You said that you have spark . If you do then you don't need to test the ign. module . If no inj. pulse then check to see if ECM getting signal ( at neg. coil term. ) or ign. module . Quote Link to comment Share on other sites More sharing options...
4.6StangRage Posted May 9, 2013 Share Posted May 9, 2013 9rider, these wires changed between '76 and 77, that is why I have a weatherpack in place. I had to modify the connection because they were different by one wire and it was a crucial wire. I check injector pulsing with my LED test light and those can be found for pretty cheap. Seriously, Check pulsing at pin #1 on the ECU with a test light that will confirm that the ECU is getting the triggering it needs. If the triggering exists that is good. I dont know the exact specs of the injector resistance but if you find one that is Out of limits (or reads "OL") or has much higher resistance than the others. That will certainly cause an engine to die and not start up until you unplug the particular injector. Quote Link to comment Share on other sites More sharing options...
9rider Posted May 11, 2013 Author Share Posted May 11, 2013 I found the problem, thanks to 4.6StangRage and all members. Problem laid in the ignition wire ( weather pack connector on 4.6StangRage's pictures), the wire looked fine , however, the conductor inside was broken. That why I couldn't detect it. My car run again, and thank you all for your helping hands. Wish you have a nice weekend with lady you love. ( Fairlady included ) Quote Link to comment Share on other sites More sharing options...
4.6StangRage Posted May 11, 2013 Share Posted May 11, 2013 Congrats! It took me quite some time as a very inexperienced tech to figure this out. Think about it, you also know how to disable the car to prevent theft. Only Z guys know how this connector works so it would make it quite difficult for others to figure it out. Quote Link to comment Share on other sites More sharing options...
MidnightCafe Posted May 17, 2013 Share Posted May 17, 2013 I found the problem, thanks to 4.6StangRage and all members. Problem laid in the ignition wire ( weather pack connector on 4.6StangRage's pictures), the wire looked fine , however, the conductor inside was broken. That why I couldn't detect it. My car run again, and thank you all for your helping hands. Wish you have a nice weekend with lady you love. ( Fairlady included ) I am having issues with my transistor ignition unit right now. Are you telling me that you essentially jiggled the ignition wire and it fixed itself? Quote Link to comment Share on other sites More sharing options...
9rider Posted May 17, 2013 Author Share Posted May 17, 2013 No, my ignition wire was damaged inside ( broken ) , However appeared perfect outside. I cut and re-wire. Quote Link to comment Share on other sites More sharing options...
4.6StangRage Posted May 17, 2013 Share Posted May 17, 2013 This wasn't necessarily an ignition issue. It was a signaling problem to the ECU. Quote Link to comment Share on other sites More sharing options...
9rider Posted May 18, 2013 Author Share Posted May 18, 2013 Test 35 pins of your ECU, help me to understand a lot tho . Quote Link to comment Share on other sites More sharing options...
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