drvrswntd Posted June 30, 2011 Share Posted June 30, 2011 (edited) As the title suggests, I am looking for some help troubleshooting what I believe are the final barriers from getting my car started: Background: 1973 240Z body, 1998 Camaro LS1, T56, PCM Electrical: The symptom: I put my key into the ignition. I turn it from lock to off, and the starter cycles/cranks. I turn it from off to acc or on, no problems (no fuel pump prime either, but I think we can figure that one out), i turn it to start and the starter goes again. Turn it back to ACC and no issue, turn it to off, no issue, turn it to lock, and the starter cycles. Another issue, probably related, is that the switch wire (below for setup) has constant power when the ignition harness is plugged in, key or no key. The setup: Black and White (BW) wire from ignition is switched power, right? So that goes to the fan/fuel pump relays and Camaro C Connectors. Black and Yellow (BY) is wired directly to the purple starter wire of the LS1. White and Red (WR) is wired from the battery, as are the PCM and Relays for the fan and fuel pump. Fuel: The symptom: Aside from the fuel pump not priming when the ignition is "ON" (which I think we can work out), giving the fuel pump constant power does not raise the pressure at the rails, and the car wont start. The setup: 240Z tank with a summit sump welded at the bottom. 90* -8AN outlet to filter, filter to walbro (mounted in the 280Z location on an extended (lower) bracket), walbro to corvette fpr, fpr to rails along driver trans tunnel, and return to upper vent line - all -8AN fittings and braided lines. The evap/expansion tank is plumbed to one gas tank outlet, the other tank outlets and evap tank inlets are sealed. A non-scientific test of feeling the lines with the pump running indicate vibration along the lines between the tank and filter, filter and pump, pump and fpr, and fpr and return. However, a few inches past the fpr, the lines to the rails seem to vibrate substantially less. I have thought of doing the following: remove filter, pump, fpr from brackets and place them all as low under the car as possible remove outlet at pump, check for fuel when pump is on remove outlet at fpr, check for fuel when pump is on remove inlet to rails, check for fuel when pump is on Other items of note: The filter is mounted where the stock 280Z pump would go, the walbro is mnounted a few inches beneath that, but the walbro is still pulling fuel through the filter above it. Also, I have the 90* outlet from the tank sump angled up with the fuel lines running just above the seam of the gas tank, recessed between the tank and the rear fascia, which is higher than the fuel pump. Sorry if I missed any details, or added any obfuscation, just trying to be clear and concise at the same time. Thanks in advance for any help. Josh Edited June 30, 2011 by drvrswntd Quote Link to comment Share on other sites More sharing options...
h4nsm0l3m4n Posted June 30, 2011 Share Posted June 30, 2011 (edited) Your ignition switch symptoms are very strange. Definitely seems like its mis-wired and not acting properly. Did you change anything from the stock wiring harness that could have affected the switch? The only modification I had to do to the stock harness was splice the ignition wire to signal my LS1 relays, etc to turn on. About your fuel pump. Working with open fuel always makes me nervous but going through the fuel system one component at a time to check everything is probably the best way to figure out where youre not getting fuel. My first suggestion (if you havent already thought of this) would be to verify all your inlets and outlets on the pump, fpr, filters, etc, are hooked up to the right fuel lines. Very easy to get mixed up Edited June 30, 2011 by h4nsm0l3m4n Quote Link to comment Share on other sites More sharing options...
drvrswntd Posted June 30, 2011 Author Share Posted June 30, 2011 (edited) Thanks for the quick reply! Your ignition switch symptoms are very strange. Definitely seems like its mis-wired and not acting properly. Did you change anything from the stock wiring harness that could have affected the switch? The only modification I had to do to the stock harness was splice the ignition wire to signal my LS1 relays, etc to turn on. Sadly, I am combining two 1973 Zs into one - the recipient of the motor was a shell, so I never saw it run. The dashboard donor car has run in my recent past. I haven't changed anything from the stock harness other than the three wires identified in my first post. About your fuel pump. Working with open fuel always makes me nervous but going through the fuel system one component at a time to check everything is probably the best way to figure out where youre not getting fuel. My first suggestion (if you havent already thought of this) would be to verify all your inlets and outlets on the pump, fpr, filters, etc, are hooked up to the right fuel lines. Very easy to get mixed up Yeah, last night i dropped the walbro, and confirmed that the flow arrow followed the fuel lines correctly. The filter's flow arrow is always visible, and I am using this picture as reference for the fpr, knowing that the return and inlet labels are switched. Today I am going to start at the rail and move backwards to see where I can get fuel to pump back into a gas can. Edited June 30, 2011 by drvrswntd Quote Link to comment Share on other sites More sharing options...
Blown77Z Posted June 30, 2011 Share Posted June 30, 2011 Thanks for the quick reply! Sadly, I am combining two 1973 Zs into one - the recipient of the motor was a shell, so I never saw it run. The dashboard donor car has run in my recent past. I haven't changed anything from the stock harness other than the three wires identified in my first post. Yeah, last night i dropped the walbro, and confirmed that the flow arrow followed the fuel lines correctly. The filter's flow arrow is always visible, and I am using this picture as reference for the fpr, knowing that the return and inlet labels are switched. Today I am going to start at the rail and move backwards to see where I can get fuel to pump back into a gas can. Electrical system: Did you put a test meter on the wires BEFORE wiring it up? If not well............ Fuel system: Are your braided fuel lines brand new? If they aren't new, check them GOOD, I had a similar problem when I got my car back on the road. I had no fuel coming from the pump to the rail. Turns out it was my fuel line...it had ruptured on the top of the line, so it didn't leak any fuel (an obvious sign of a bad line) and was pulling in air from the ruptured portion making a gurgling sound thru the line when it tried to start Are you using an adjustable FPR near the fuel rail? Quote Link to comment Share on other sites More sharing options...
drvrswntd Posted July 1, 2011 Author Share Posted July 1, 2011 Electrical system: Did you put a test meter on the wires BEFORE wiring it up? If not well............ Fuel system: Are your braided fuel lines brand new? If they aren't new, check them GOOD, I had a similar problem when I got my car back on the road. I had no fuel coming from the pump to the rail. Turns out it was my fuel line...it had ruptured on the top of the line, so it didn't leak any fuel (an obvious sign of a bad line) and was pulling in air from the ruptured portion making a gurgling sound thru the line when it tried to start Are you using an adjustable FPR near the fuel rail? I got the fuel portion figured out, I am ashamed to admit it was just a polarity issue on the pump. Works like a charm now. We tested the wires before making the switch, and the BW wire gave voltage only with the key in the on position. Now that it is wired up, that wire seems to have constant power (even with no key), but so does the thicker WR wire that we are using for constant. No idea why there would be two all time hot wires at the ignition. Our wiring matches the coloring in the Haynes manual, and while I know we cannot absolutely rely on it, I have to start somewhere. If anyone can help me read the ignition wiring section, I see that at position 1(L), white red and blue red are connected. Off, nothing is connected. At 1® BW,WR and LR are connected. And at 2® BY, WR and GL are connected. I assume that 1(L) is ACC, 1® is on, and 2® is start. WR is constant through all, and so is constant power. LR is at ACC and on, so it must have switched power at accessory, and BW is on at on only, so is switched for on items (fuel pump among them, don't want that running everytime you turn on ACC only). BY is starter, and that is working fine, except it also triggers mid cycle between off and lock (a local builder says he had the same problem and couldn't get rid of it, so just went push button). Quote Link to comment Share on other sites More sharing options...
h4nsm0l3m4n Posted July 1, 2011 Share Posted July 1, 2011 (edited) For constant 12v I wired my harness to the positive side of the starter wire. Out of the ignition switch I only accessed the one wire (probably BW but I cant remember now) for the ignition "on" signal. If you can verify the LS1 harness is working as intended you can assume the problem lies somewhere in your stock wiring. Did you already test that the harness behaves properly by powering it up without hooking it up to the ignition switch? Also this might sound kind of stupid but what do you mean by "making the switch." Did you take apart the ignition switch assembly? If you take the assembly apart you will find its made of 2 parts, the key/lock cylinder part and the actual ignition switch. The key rotates a small tab on the ignition switch that turns a slot on the ignition swith to "on", "start", etc positions. It is possible (I think), if you turn the ignition switch slot to a different position, to put the assembly back together incorrectly. I accidentally did this and got some wierd, backwards sort of behavior from the switch since its not in the correct position anymore. Luckily this is easy to test and fix. Edited July 1, 2011 by h4nsm0l3m4n Quote Link to comment Share on other sites More sharing options...
drvrswntd Posted July 1, 2011 Author Share Posted July 1, 2011 Making the switch meant swapping from datsun wiring to conversion, could have said "making the wiring changes in the first post". The starter is from another z that had previously worked correctly, but it is possible that I just never noticed the starter cycling between lock and off. I am almost positive the issue lies somewhere in the stock ignition switch or harness, or possibly one of the under dash harnesses is plugged incorrectly. In other words, I do not suspect the ls1 ECM as a culprit. Frankly, I assume that in part because wait4me did my harness conversion, and I trust their wiring more than mine. Tomorrow I will try to re-identify which wires are providing what signal in what key position, and will check continuity again on my current wires. Quote Link to comment Share on other sites More sharing options...
drvrswntd Posted July 5, 2011 Author Share Posted July 5, 2011 (edited) Well, I got sidetracked putting on new brakes, wheels, tires and re-packing the front hubs. A friend suggests that I need a relay from the ignition to the switched power supply; i.e. the key turned to on sends signal through the black and white wire to a relay which then sends power, as opposed to using the black and white for direct switched power. Going to try that tonight or tomorrow, and see if that helps out the constant power issue. I also spoke with a local builder who says that he has seen the starter engagement issue on several Z cars in the past; always where a start signal is sent between lock and off, and he has never found a fix other than converting to push button start. I will see if I can find the solution, if there is one, before I commit to push button. Some non-relevant eye-candy: Edited July 5, 2011 by drvrswntd Quote Link to comment Share on other sites More sharing options...
drvrswntd Posted July 5, 2011 Author Share Posted July 5, 2011 Well, found this thread from prior in the year, and it confirms that WR is constant, and the BW and BY wires. However, I will check on the ammeter wiring that the thread finishes with, sounds like that might be the cause. http://forums.hybridz.org/index.php/topic/86807-240zls1-electrical-questions/ Your problem sounds like it is related to the ammeter gauge wiring. When you take that gauge out, you have to connect the two fat white wires together so that circuit is still complete, just as you suggest. I had the same problem and now all is good. Good luck! I did hook that up and all worked after I posted it to try it since I suspected that. By jumpering the old alternator wire I was back wiring that circuit to everything downstream of the ammeter. Without it connected everything before the connection was hot. Thanks for confirming. I also found a bad ground which was causing some other gauge weird problems. Quote Link to comment Share on other sites More sharing options...
drvrswntd Posted July 6, 2011 Author Share Posted July 6, 2011 (edited) Well, friends and I may have traced the cause of constant power at our switched side - by testing every connection from ignition to switched power circuit breaker, we found that when the dome light circuit is closed/fused, we get constant power at switched. When we break that circuit, switched is switched and constant is constant. FYI, no sensors in the doors right now, and no dome light installed. As to why that would be, I have no idea. Fuse block "looks" ok and tests fine otherwise. Will keep troubleshooting tonight. Edited July 6, 2011 by drvrswntd Quote Link to comment Share on other sites More sharing options...
drvrswntd Posted July 7, 2011 Author Share Posted July 7, 2011 (edited) Well, by leaving out the fuse for the dome lamp, looks like we got the major issues worked out. This weekend I should finish up the clean=up of body wiring harness, and reassembly of everything to confirm proper function. Last step will be to decide whether to 1) go aftermarket tach, 2) send it to JCI for reconfiguring, or 3) reconfigure it myself using this method: http://www.dinoplex.org/tachoconversion/index.html Edited July 7, 2011 by drvrswntd Quote Link to comment Share on other sites More sharing options...
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