ctc Posted November 6, 2013 Share Posted November 6, 2013 Did you check spark plug ? Ignition wire and firing sequence ? First post, strong spark. No injector firing. Quote Link to comment Share on other sites More sharing options...
ISPKI Posted November 6, 2013 Author Share Posted November 6, 2013 I did not get a chance to check the resistance but I will do that today. Here are the photos of the ECM and ECM plug. I dont recall which end to start counting from but some of the pins are not lining up. I looked online and that appears to be how they are configured, just seemed odd to me. I am leaving now and will continue testing and report back later tonight with results. Quote Link to comment Share on other sites More sharing options...
ISPKI Posted November 6, 2013 Author Share Posted November 6, 2013 Of course, some of those pins on the plug are damaged, cant be good...will straiten them out when I get to it. Quote Link to comment Share on other sites More sharing options...
ISPKI Posted November 6, 2013 Author Share Posted November 6, 2013 (edited) I have continuity on pins 5, 16, 17, and 35 now. I have +12v on pin 10 with key turned to "on" but I do not have 12v on pin 4 with the key turned to "start". Currently testing the injector wires. Trying to figure out if they are in the correct order or if I have the wires flipped. What should the resistance be on the injector wires? I was getting very low resistance Do you guys know which connector on the injector is supposed to be receiving the 12v and which one is supposed to connect to ground? Edited November 6, 2013 by ISPKI Quote Link to comment Share on other sites More sharing options...
ISPKI Posted November 6, 2013 Author Share Posted November 6, 2013 Looks like I am getting 0.4ohms on all the injectors. I have continuity to ground from (I think) pin 72 on the relay - I tested the only black wire coming out of the upper plug. I also tested pin 21 and 34 (cold start circuit and air regulator circuit) and those both failed to have battery voltage with key turned to "start". Quote Link to comment Share on other sites More sharing options...
ctc Posted November 6, 2013 Share Posted November 6, 2013 (edited) The ECU needs power when cranking or the injectors will not fire. I don't have my FSM at work, but pin 4 should have battery (+12V) while cranking. Use the FSM page I referenced above to verify the pins. Also double check the injectors are powered when the engine is cranking. The way the key works is to disconnect the run position and power everything from the start (crank) posisition. So, If you only checked for power to the injectors and ECU while the key is one, they might not be recieving power when the engine is being cranked. I would focus on getting the ECU power when the engine is cranking. A check you can do, is to jumper the starter solenoid while the key is in the on position. This will cause the starter to engage without having the key in the start position. If the ECU is functioning correctly the engine will start. Resistance between the ECU plug and injector plug should be really low. It would show infinite ohms if there was a open. Just wanted to make sure you did not have a break in the wire between the injector and the plug. Edited November 6, 2013 by ctc Quote Link to comment Share on other sites More sharing options...
ISPKI Posted November 7, 2013 Author Share Posted November 7, 2013 Right. I am going to take closer look at the ignition switch tomorrow morning. I do rebuild it with new parts as the original was broken and was very hard to get the key to engage. I recall that the switch assembly did not really go together nicely with the aftermarket components so maybe there is an issue there. Thank you BTW for all the help thus far. Quote Link to comment Share on other sites More sharing options...
ISPKI Posted November 8, 2013 Author Share Posted November 8, 2013 OK, I checked power to the injectors with my multimeter by sliding the red probe into one pin on the injector plug and the other I wedged between the valve cover bolt and the cover, no power before turning key to "on", 12v with key turned to "on" and 12v with key turned to "start". I jumped the starter with the key turned to "on" for 4-5 seconds and, as usual, it started for a second and then immediately died. Quote Link to comment Share on other sites More sharing options...
ISPKI Posted November 8, 2013 Author Share Posted November 8, 2013 (edited) OK, I went back to the FI handbook and rechecked the ignition relay. It clicks when turned to "on" but does not click when turned to "start". This lead me back to double check Pin 4 on the ECM which I believe is just the wire that supplies power to the ECM? In the schematic, Pin 4 should have a wire that goes from ECM -> Relay, Relay -> Ignition Switch, ignition Switch -> Fuse, Fuse -> +BAT. Since I jumped the starter with the key turned to "on" and it did not want to start up and run, that basically narrows the problem down to the ECM or the Relay correct? I know the fuse and the cables are good up until it gets through the firewall and into the relay. I think I am going to try and pull the relay out and look inside it to see if there is any damage inside. Going back and double checking some of the other circuits that go through the relay and others are also failing - Pin 20 to ground has no continuity, pin 34 to ground also has no continuity. Looks like the relay is the source of my issue here. Will know more once I take it apart. Edited November 8, 2013 by ISPKI Quote Link to comment Share on other sites More sharing options...
ISPKI Posted November 8, 2013 Author Share Posted November 8, 2013 Well, I dont see anything really wrong with the internals of the relay, its all very clean inside. Quote Link to comment Share on other sites More sharing options...
ctc Posted November 8, 2013 Share Posted November 8, 2013 That double relay was problematic for me. I had two of them go bad very quickly. Bosch l-jetronic used a similar double relay, but much better sealed. Sounds like you are making progress. If you get voltage to the ECM and still no spark, I would go find a known good ECM. Quote Link to comment Share on other sites More sharing options...
NewZed Posted November 8, 2013 Share Posted November 8, 2013 (edited) Pin 4 gets power during Start, along with the CSV system. Do you have a fuel pressure gauge connected? I don't see any sings that you've confirmed that the fuel pump runs and continues to run after the engine starts, Edited November 8, 2013 by NewZed Quote Link to comment Share on other sites More sharing options...
ISPKI Posted November 8, 2013 Author Share Posted November 8, 2013 I have a pressure gauge right at the start of the fuel rail, after the fuel filter. Maintains about 37ish psi. I have spark, I do not have injector pulse. It starts and runs with starter fluid but dies as soon as I take away the fuel source. I tried to fire the injectors manually by tapping the negative terminal on the coil to ground but the injectors did not click. So far, all my tests point to the relay as all the circuits that have failed pass directly through the relay but I don't see anything wrong with the relay itself. Nothing appears damaged inside of it. I think I will need to simply buy a new unit just to test and see if that is actually the problem... does anyone have a source for these? I have only found one and it was quite expendive . Quote Link to comment Share on other sites More sharing options...
ctc Posted November 8, 2013 Share Posted November 8, 2013 The last one I bought was around $100 used. I had a very hard time finding one. Alternate is to use two individual relays with a diode as shown in the FSM schematic. Quote Link to comment Share on other sites More sharing options...
NewZed Posted November 9, 2013 Share Posted November 9, 2013 EF-55 to -57 of the FSM. There are a page and a half of testing procedures for the relay, pin by pin. Could save you some money. Quote Link to comment Share on other sites More sharing options...
ISPKI Posted November 10, 2013 Author Share Posted November 10, 2013 (edited) Well I plugged the open relay back in and started the car to see if the relay functioned. It does engage both contacts, the one that engages when turning to start just doesnt click as loud as the one when turning to on, and it does not engage when the wire is disconnected from the starter solenoid which must be why I did not feel it click before. So just to clarify where I should be in the EFI bible - My vehicle will start for a second after sitting over night and then die. After that, I cant get it to start although it does sort of cough every few seconds or so. I was looking under "engine does not start" but maybe there are other tests elsewhere that I should be doing. Anyways, I am trying to test the ignition lead wire (a step that I skipped previously), just waiting for the rain to let up... Edited November 10, 2013 by ISPKI Quote Link to comment Share on other sites More sharing options...
ISPKI Posted November 10, 2013 Author Share Posted November 10, 2013 (edited) Well I went back and tested the injectors individually. I slipped a wire into the #6 pin on the ECU plug (pin#31 I believe), turned the key to "on" and tapped the wire against a bolt by the pedals. I could hear a very faint clicking sound from the injector. Also - Just to make sure it was firing, I checked the fuel pressure before and after grounding. The pressure before I started was at 30 psi, I clicked the injector maybe 8 times and the pressure dropped to 21 psi, then I kept checking other injectors and it dropped to 0. This confirms that the wiring harness from the battery, through the ignition switch and relay are all intact and that basically leaves the ECM as the only possible issue. I will order one tonight unless anyone has any other ideas of what might be the issue. Also - Does anyone have a good source for these? Remanufactured from Rockauto costs about 250$. Edited November 10, 2013 by ISPKI Quote Link to comment Share on other sites More sharing options...
ctc Posted November 10, 2013 Share Posted November 10, 2013 (edited) $250 sound about right for remanufacture. Some time you can get a deal on a used one, but if you want the certainity of remanufacture, you are going to spend some dollars. Edited November 10, 2013 by ctc Quote Link to comment Share on other sites More sharing options...
NewZed Posted November 10, 2013 Share Posted November 10, 2013 Try borini63. He parts out a lot of cars and some of them were running when he got them. Bad ECU's are not common. Pretty easy to plug and unplug also, if you can find someone to loan you theirs for a try or a pre-purchase test. Quote Link to comment Share on other sites More sharing options...
ISPKI Posted November 11, 2013 Author Share Posted November 11, 2013 I would love that zed, unfortunately I live in CT and people here do not believe in things like datsuns, freedom, happiness...did I mentions datsuns? Seriously, it took me two years to find this one. I am going to pull my ECU out tomorrow and take it apart to see if anything is damaged inside. Quote Link to comment Share on other sites More sharing options...
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