rackolamb1 Posted April 25, 2009 Share Posted April 25, 2009 So I've searched the forums for days trying to find what I need, but it seems most posts end with no resolution. My gut feel is that I may have an ECU issue (ignition board), but before spending money on a used one, I would like help in verifying this. I've dropped in an 83' L28ET engine into my 71 240z, this includes the engine, harness, coil + ignitor, ecu, etc. I've followed all the diagrams (and variations) and have verified power to the ecu via ignition switch power (on at run position), fuel pump kicks in for 5 seconds when the ecu powers up. I believe my CAS is alright as I can take the distributor out and spin it and I hear the injectors click and the fuel pump turns on. The issue I have is I get zero spark. I've verified 12volts at the coil (via the 12volt switched power to the ignitor). The pulse wire (pin 5 from the ECU) has been ran to the other post on the ignitor. I've hooked up a timing light to see if it flashes while cranking (no go), I've tried a spark plug (no go). The only thing that seems logical to me is that I'm not getting the pulse from the ECU. Unfortunately I don't think I can test this easily. I did buy a good used coil ignitor and get the same thing. I've even replaced the transistor on one of the ignitor's to see if maybe both of them could have been bad. At this point I don't know what else to check. One thing to note, is that my ecu light goes out when I crank the engine, and comes back when I stop cranking. Also, when my ecu power is run from the ignition switched power, it goes to zero volts while cranking. This didn't seem right to me, so I ran power directly to the battery and it does the same thing. I've tried so many things, that at this point it's probably a simple fix, but it feels like my brain if fried (maybe like my ECU ). Can someone help me out? Thanks... Quote Link to comment Share on other sites More sharing options...
WizardBlack Posted April 26, 2009 Share Posted April 26, 2009 Erm, dead battery? It will read 12V or close to it, but soon as you pull a load on it, it drops to virtually nothing. Quote Link to comment Share on other sites More sharing options...
ShaggyZ Posted April 26, 2009 Share Posted April 26, 2009 Have the battery tested. If it comes out good, then start looking for shorts or some reversed wiring. Quote Link to comment Share on other sites More sharing options...
rackolamb1 Posted April 26, 2009 Author Share Posted April 26, 2009 Thanks for the suggestions... I've been using the battery from my 79 CJ7 just to try and get it running. It works fine on the Jeep, but it is about 8 years old. I'll have the battery tested tomorrow, or just buy a new one, as I'll need one anyway. I'll reply back with the results. Quote Link to comment Share on other sites More sharing options...
WizardBlack Posted April 26, 2009 Share Posted April 26, 2009 Juice enough to get a good running vehicle is much less than trying to crank something with a rough tune over, etc. LUK. Quote Link to comment Share on other sites More sharing options...
rackolamb1 Posted April 26, 2009 Author Share Posted April 26, 2009 OK, new battery and same issue. The car cranks like a mofo, but still no spark. Checked the volts during cranking and it drops to like 10.6v, which I think may be why the ECU power led turns off while cranking. I am temporarily running 12v directly from the battery for the ecu power (b/w wire), as my switched power I was running drops to 0v while cranking... What part of the ECU sends the pulse? I know it's off of pin #5. Could it be that just that part of the ECU is bad? The ECU does seem to control the fuel pump signal though, as it powers the pump for 5 seconds when it gets power. Should I pick up a used turbo ECU... Quote Link to comment Share on other sites More sharing options...
loy Posted April 27, 2009 Share Posted April 27, 2009 How about the FI Relay? Are you getting ignition to it? When I had the problem of not starting on my swap, I was using accessory instead of ignition, meaning no power while cranking. http://forums.hybridz.org/showthread.php?t=99620 Also does your fuel pump turn on (prime) at "ACC" or "On" ? Led will turn off while cranking. Quote Link to comment Share on other sites More sharing options...
rackolamb1 Posted April 28, 2009 Author Share Posted April 28, 2009 I have the b/w wire hooked up to the "on" wire coming out of the ignition switch. I've verified this more than once. When I turn the key to the "on" position, my fuel pump kicks on for 5 seconds and the light on the ECU comes on. My problem with it hooked up that way, is that when I attempt to start the engine, the "on" position loses it's voltage (0v). Once I stop cranking the voltage comes back. This is when I decided to move the b/w wire from the "on" postion and hook it straight to the battery for testing, but that didn't seem to help any. I need to verify voltage on the b/w wire with it setup this way, but didn't have a chance to do that last night like I wanted. Does the FI Relay get power from the b/w wire, or is there another wire I need to look into for that? Quote Link to comment Share on other sites More sharing options...
loy Posted April 28, 2009 Share Posted April 28, 2009 If you wired both the FI relay and ignitor with the same "On" wire then it should be ok. If not then check the b/w wire on the FI relay, it should see 12 while on and cranking. That switch wire you are using sounds like the ACC wire. The "ON/ignition" has about 12v during crank and on. Figure N http://forums.hybridz.org/showthread.php?t=99620 Quote Link to comment Share on other sites More sharing options...
rackolamb1 Posted April 29, 2009 Author Share Posted April 29, 2009 FI relay wire and ignitor are currently both hooked to 12v direct from the battery until I can get this thing fired up. I verified voltage on these during cranking and it I get 10.7v. When not cranking, I get 12.6v on these. Since I have an 83 setup, I have the 8 prong plug by the ECU. What wires do I absolutely have to have wired from this plug to get it to fire? What I have hooked up is the y/w wire coming from the ECU to the ignitor (verified it is pin#5), the yellow wire for the cold start tied to the start position power, and a black wire grounded. Am I missing anything there? Does the ECU ground itself via the chassis? If so, I just have it laying on the floorboard. Thanks... Quote Link to comment Share on other sites More sharing options...
evildky Posted April 30, 2009 Share Posted April 30, 2009 bad ignotor? got a smart probe? Quote Link to comment Share on other sites More sharing options...
HowlerMonkey Posted May 1, 2009 Share Posted May 1, 2009 Are the grounds connected to the intake manifold? Quote Link to comment Share on other sites More sharing options...
rackolamb1 Posted May 2, 2009 Author Share Posted May 2, 2009 I do not have a smart probe, can these be picked up for a fair price... At this point I'd like to test my ignitor and see if that is my issue. I have 3 grounds on the intake manifold so I'm pretty sure I'm good there. I also have a ground coming from the AFM harness that I have connected to the same ground as the ignitor. I really wish I had taken the old wiring out so I'd have a better idea of what goes where. Thanks for the suggestions and keep em coming.... I'm dying to drive this car. Quote Link to comment Share on other sites More sharing options...
evildky Posted May 2, 2009 Share Posted May 2, 2009 i believe thetoolwarehouse.net sells their version of the "logic probe" for around $40, which is about 1/3 of what it goes for on the truck Quote Link to comment Share on other sites More sharing options...
rackolamb1 Posted May 4, 2009 Author Share Posted May 4, 2009 I got a new ignitor coming. I will post the results after I get it installed. Couple other questions, does the ECU need to be grounded? Could it be my FI Relay? Would the injectors click if that relay was bad? At this point I just want spark, I don't care about anything else. Thanks. Quote Link to comment Share on other sites More sharing options...
HowlerMonkey Posted May 4, 2009 Share Posted May 4, 2009 The ecu case does not require a ground as I routinely run them while holding them in my hand. Quote Link to comment Share on other sites More sharing options...
ShaggyZ Posted May 4, 2009 Share Posted May 4, 2009 The ecu case does not require a ground as I routinely run them while holding them in my hand.That doesn't sound right. I think what you meant is that it doesn't require a case ground. It's an electrical device so you can be sure one of those wires that plugs into it is a ground. Further, it could be possible to have bad connections (shorts) in your case which are acting as grounds; your ECU may technically need a case ground but it's been substituted when unbolted by the aforementioned shorts. Quote Link to comment Share on other sites More sharing options...
rackolamb1 Posted May 8, 2009 Author Share Posted May 8, 2009 Quick Update: I installed the new ignitor and I now have spark. WooHoo, progress. The car barely sputtered and wouldn't. I took the plugs out and squirted in some starting fluid and it started, but died quickly. So I think my next step now is to install a fuel pressure guage and clean the injectors. When I took the plugs out they were bone dry. I'll search for a link on cleaning the injectors, as I'm sure it's been posted.. Thanks for the help. I'll post a victory post when I get it running for good. Quote Link to comment Share on other sites More sharing options...
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