HLChoppers Posted February 11, 2007 Share Posted February 11, 2007 I found that some of my injector wiring has broke apart. I am repairing them and tested the rest of the wiring. My question is sould both wires leading to each injector have power? I thought one is supposed to be a ground and the other a pulse. Please help Quote Link to comment Share on other sites More sharing options...
z-ya Posted February 11, 2007 Share Posted February 11, 2007 One wire should measure 12V. The other depnds on if the engine is running, and what instrument you are using to measure it. If you are using a voltmeter, then it will most likely read a positive voltage. If you have an oscilloscope, you should be able to see the injector being pulsed on an off at some fixed duty cycle. Does it run? If so, you most likely have it wired right. Quote Link to comment Share on other sites More sharing options...
Careless Posted February 11, 2007 Share Posted February 11, 2007 I found that some of my injector wiring has broke apart. I am repairing them and tested the rest of the wiring. My question is sould both wires leading to each injector have power? I thought one is supposed to be a ground and the other a pulse. Please help I'd just wire it as the FSM says. if it's only two wires, that shouldn't be that hard. where did they break? Quote Link to comment Share on other sites More sharing options...
HLChoppers Posted February 11, 2007 Author Share Posted February 11, 2007 It was running but it had a intake manifold to head leak (gas coming out). I replaced the gasket and now it is not starting. I have temp fixed the wiring to the injectors. I have spark at all plugs, timing is still on (distributor was not touched). I know I have fuel to the injectors. I did take the egr system off but keeped the fuel pressure regulator hooked up to vaccum aslo the advance as well. I was using a mulitmeter when I tested the wires and both wires on every injector was running 11-12 volts. Quote Link to comment Share on other sites More sharing options...
Pascal Posted February 21, 2007 Share Posted February 21, 2007 maybe i can help a lil! ^^ Almost al cars have positive as togheter witch you can measure when you give signal with Ignition key, after you did give contact you can measure on all 4 or 6 in jectors positive. What ECU give is negative! So for example you can even turn on engine with wire conected to negative of your battery or make even pulsing as you accelerate with your other hand on buterflly. I normally do that to test some new engine that i need to put in some other type of car.swo no worries about mistake. Just give contact and measure where is positive and other wire is 4 or 6 different wires from each pin on your ECU. Have fun and i hope i did help a bit Quote Link to comment Share on other sites More sharing options...
Daeron Posted February 26, 2007 Share Posted February 26, 2007 maybe i can help a lil! ^^ Almost al cars have positive as togheter witch you can measure when you give signal with Ignition key, after you did give contact you can measure on all 4 or 6 in jectors positive. What ECU give is negative! So for example you can even turn on engine with wire conected to negative of your battery or make even pulsing as you accelerate with your other hand on buterflly. I normally do that to test some new engine that i need to put in some other type of car.swo no worries about mistake. Just give contact and measure where is positive and other wire is 4 or 6 different wires from each pin on your ECU. Have fun and i hope i did help a bit Allright, not to be rude.. your English is FAR better than I can speak any foreign language (although I am learning more spanish daily.) However, JUST to be clear, what he was saying is that most fuel injected vehicles provide a constant feed of positive voltage to the injectors, and let the ECU switch them by switching ground. In other words, you should have a constant 12V+ to one side of the injector, and nothing to the other side. You should be able to check for continuity between the other side, and ground, and get nothing.. UNLESS you are cranking the engine, and then you should see an intermittent ground on the other one. Now, I read the L-Jetronic Bible about two years ago.. I havent had my Z running since shorlty BEFORE that, so I havent worked on Z FI since then.. BUT I am pretty sure he was exaxtly right, and the ECU switches ground to the injectors to activate them. IIRC, the constant positive comes from the dropping resistor, but don't quote me on that... So, if you have the negative lead on a good chassis ground, and the positive lead on each injector wire, and crank the car, one wire on each inj. should run +12VDC, steadily. the other wire should register nothing, or MAYBE show an intermittent -12VDC. More likely, the other wire would register nothing, and then you leave the leads connected as they were to the other wire, and switch your multimeter to continuity.. then, while cranking, you should see fluctuations between continuity and non.. IE, no resistance, then infinite resistance. Now, as I said, I havent worked on my Z in three years.. and even then, I was no guru.. but i am trying to help. Hopefully I am not opening my mouth to insert my foot, but I normally don't even try to help if I am not fairly certain I am right. Also, hopefully if I am misleading or incorrect in any way, someone will chime in and correct me Quote Link to comment Share on other sites More sharing options...
naviathan Posted February 26, 2007 Share Posted February 26, 2007 Try putting a noid light on each side of the injector as the car is cranking. One side should flash the other should stay constant. Quote Link to comment Share on other sites More sharing options...
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