s30kid Posted August 9, 2012 Share Posted August 9, 2012 I was wondering how the ignition coil controls the firing of the fuel injectors. When I looked at how the coil was wired it didn't look like it went to the ecu harness at all. Just from the distributor. And a + and - If someone could explain it to me that would be nice. And I do have the owners manual, The FSM. and the efi bible. I've looked through but all I could find was what pins to test with the volt meter. Did I miss something? Quote Link to comment Share on other sites More sharing options...
s30kid Posted August 9, 2012 Author Share Posted August 9, 2012 Update: test #1: I did the ignition coil trigger imput circuit test from the efi bible, I tested pin #1. Its supposed to read 12v on the on position. It read 0. Test #2: I also did the control unit power input circuit test. testing pin 10 for 12v. and that test i got 12v. So, what does my first test tell me? Why wouldn't pin #1 be getting 12v? Quote Link to comment Share on other sites More sharing options...
NewZed Posted August 9, 2012 Share Posted August 9, 2012 Check that you have 12 volts at coil (-) with the key On. If not, check coil (+). You should have 12 volts on both sides with the key On. If you have 12 volts at coil (-), then check the following: There is a blue wire connected to the coil (-) post that runs through the harness to Pin #1. If you're not getting 12 volts at Pin 1 there must be a break in the circuit somewhere. Could be at the coil or anywhere in between. 77 still has the ballast resistor. I think that the blue wire actually connects to a post on the ballast that is also connected to coil (-). If you've messed with the wires at the coil and ballast, find that blue wire, check continuity (resistance) to Pin 1, then connect it to coil (-) of it's the correct wire. Quote Link to comment Share on other sites More sharing options...
s30kid Posted August 9, 2012 Author Share Posted August 9, 2012 I checked the Coil I have 12v at The + and - terminals. Quote Link to comment Share on other sites More sharing options...
s30kid Posted August 9, 2012 Author Share Posted August 9, 2012 Do you think that the ballast resistor could be bad? Quote Link to comment Share on other sites More sharing options...
NewZed Posted August 9, 2012 Share Posted August 9, 2012 The post for the negative side would just be a terminal for connecting wires. It might not even be used. You'll have to take some measurements to know what's working working right. Quote Link to comment Share on other sites More sharing options...
s30kid Posted August 9, 2012 Author Share Posted August 9, 2012 Well is there any help you can give me. I'm relatively new to the electronics side of cars. I'm kinda shooting in the dark. I did the tests and that's it. The most I know would be to replace peaces one by one till it runs. But that's not always smart. It's also costly. Quote Link to comment Share on other sites More sharing options...
NewZed Posted August 9, 2012 Share Posted August 9, 2012 Turn the key On and measure voltage to ground from the coil (+). then do the same from the coil (-). If you don't have voltage there you won't have voltage at Pin #1. If you have voltage at the coil (+) but not coil (-) then you have a bad coil. If you don't have voltage at coil (+) at all then you have a power supply problem to the coil. If you have power at coil (+) and coil (-) but none at Pin #1 then you have a break in the circuit from coil (-) to Pin #1 that you will have to track down. Quote Link to comment Share on other sites More sharing options...
s30kid Posted August 9, 2012 Author Share Posted August 9, 2012 Thankyou so much. You have been a lot of help. I'm sure I will be able to trace the break. The car sat for a Long time at a junk yard I'm not supprised there would be faulty wiring. Tell me I I'm correct tho, I traced the negative wire, it looks like it goes to the ballast resistor. From there it goes to the front of the car by the headlights. Across the front of the radiator to the other side of the engine over to where the fusible links are. Is that correct? Quote Link to comment Share on other sites More sharing options...
s30kid Posted August 11, 2012 Author Share Posted August 11, 2012 UPDATE!!!: Today I got my car running. Sorta I found out that the pin #1 was not even connected to the (-) coil side. So I ran a jumper wire from pin 1 to the (-) coil. Plugged everything back in started the car and it ran. But didnt want to rev. Thats okay right now im just glad I found the problem. But, while the car was idling I reved it a few times... Or tried to, and then one of the fusible links blew. If your standing on the passenger side of the car looking at the 2 fusible link holders, its the one on the right closest to you. Which link is this and why would it have blown? Also is there supposed to be a resistor between the pin #1 and the (-) coil? And the absence of one caused the fusible link to blow? Quote Link to comment Share on other sites More sharing options...
s30kid Posted August 11, 2012 Author Share Posted August 11, 2012 This is the wiring diagram i found on xenons30.com. Quote Link to comment Share on other sites More sharing options...
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