RPM Resto & Custom

Ok just an update.....and unfortunately I have 2 seperate threads going on this issue now...other is in the Help Me section. I have the csv problem narrowed down to a specific area at this point. The fuel injection system relay is supposed to get 12V from the ignition switch in the Start position on a black/yellow wire at the switch which I have. From there it should travel down to the relay passing through a 4 wire connection on it's way. At this connection the wire color has changed from black/yellow to solid yellow. By the time the wiring hits this point I've lost my 12V signal. If I jumper from the switch down to this point the csv works perfectly. Does anyone know where this wire travels and splits off from the ignition switch down to the 4 wire connector? I followed it up under the dash but it goes above the pedal bracketry and behind the speedo and tach where I can't see it anymore or unwrap any more of the harness protection.

Alright I've just about got this narrowed down but I'm stuck at this point. It looks like I'm on the right track with not getting 12V from the ignition switch black/yellow wire down to the yellow wire in the 4 wire connector that eventually feeds the fuel injection relay. I ran a jumper directly from the 12V Start position on the ignition switch down to the yellow wire on the 4 wire connector and the cold start injector works perfectly when you crank the car over. So where am I losing my 12V signal between the ignition switch and that 4 wire connector?? I followed the wires up under the dash as high as I could but they go above the heavy bracketry that the pedals attach to and behind the speedo/tach area.

Little update. I got the fuel pump pumping again but I'm not sure the logic behind how. It seems the cold start injector has to be grounded to the intake in order for the fuel pump to run. Also the pump won't run with the small wire off of the starter solenoid and the ignition in the Start position still which I believe it should do. So with the cost start valve grounded the engine runs now. However the valve still isn't operating properly. If I prime the fuel system and jumper the csv off of the battery it sprays fuel so the valve itself is ok. The thermotime switch is brand new as I suspected that to be my original problem after my ohmeter readings didn't match what the FSM specifies. I ran the diagnostic outlined in the FSM for the thermo time and FSV that involves jumping both sides of the thermotime connector and testing pin 21 on the injection controller harness while cranking. I don't get a steady 12V...it seems to come and go and I can hear the relay clicking. Is that all I'm supposed to have or should it be constant? Also if I plug a fuel injector noid light into the harness for the csv I get no signal. However maybe that's because my injector needs to be grounded for some odd reason?

Car is a 75 280Z with an XR3000 ignition setup. Ok so I've been trying to track down a cold start injector that wasn't working and now somehow over the weekend the fuel pump has stopped operating. I've tested the fuel injection relay as per the FSM as well as the cold start valve itself and the thermo time switch. Not sure how but it looks like I'm not getting 12V from the ignition switch down to the fuel injection relay now. There is 12V exiting the switch on all of the proper terminals in the Start and Run positions. After looking through some wiring diagrams it looks like at least in the Start position I should have 12v coming from the black/yellow wire at the switch and it makes it's way down to a 4 wire connector that has 2 green and 2 white wires on one side and the other has yellow, red/white, and 2 others. If I read the wiring diagram right the 12V from the ignition switch should be coming down to this yellow wire and feeding the fuel injection relay. Both the black/yellow wire from the switch and the yellow wire from this connector go up under the dash too far for me to find where they would pair up. Am I correct that these wires should attach? If I jumper 12V right from the switch to the 4 wire connector where the yellow wire terminates the fuel pump runs so I know the pump is ok. Plus it's only a week old. There is no other relay for the fuel pump that I may have blown is there?

Looks like the Black with Yellow should be my wire from the Positive Battery Fusible Link eventually ending at the ignition switch...however this isn't showing continuity all the way through. I found a wiring diagram for a 75 but the wire colors don't seem to match up. My fuel injection relay has blue wires going into it instead of red like the diagram shows...however it looks like my red wires coming in from the engine bay might switch over to blue in the harness right before it branches out 6" into the fuel injection relay...not sure why. My continuity from the fusible link to the upper part of the relay at the blue (red) wire is good....but on the lower half of the relay the continuity doesn't continue back out of the blue (red) wire. There are two small "nubs" on the bottom of the relay that nothing can connect to and I have continuity there. Does this mean the relay is bad??

Ok I just spent about 2 hours going through different tests. It looks like I'm getting no power to the cold start circuit from the ignition switch as best as I can tell. I have continuity from the csv to the ignition relay on both sides of the relay. And I have continuity from the csv to the connector going into the fuel system controller. This seems to leave me with the wiring going from the fusible link to the ignition switch. The fusible link is good and I seem to have continuity from the fusible link to the ignition relay...so I assume it's bad from wherever the fusible link line branches off into the ignition switch. I can't find continuity from the fusible link into any of the wires going into the ignition switch but according to the FSM there whould be one going in and then when the ignition switch is in the start position it sends power from that input out to the CSV system. Does anyone know which wire into the ignition switch should be coming from the fusible link? I'm also not sure how the car would start and run with no power coming in from the fusible link?

Gotcha. I'm still thinking something in the CSV circuit however since the harness to the actual valve gets no electrical pulse. I just spoke with Mike at Banzai Motorsport and he suggested looking into the CTS as it may not be telling the computer it's cold enough. The actual CTS is new within the last year but maybe it's a wiring issue?

Zed....the spec for the Thermo Timer is 70-80 ohms....so my reading of 55 seems to be well out of spec....but like I said that's on a brand new switch. As for the fuel pressure dropping off....could be. I just installed a new Nissan fuel pump so I'd assume the check valve is good. The regulator however I didn't know could bleed off. How can I test this? Also I stated above the csv works if I jump it directly off of the battery so I'm ruling that out. If I put a fuel injection noid light into the connector for the csv I still get no pulse.

Hey guys....I'm trying to fix what is basically an extended cranking problem on a 280 that's been warmed over with a cam and some head work. My customer wants it to start a bit quicker on initial start up. I figured it was just an issue of the engine building up some compression first with the larger cam but after digging in a bit it looks like the cold start injector isn't working. I followed the FSM tests...if I jumper the injector off of the batter directly it cycles and squirts a small amount of fuel...which I assume is ok since the fuel pump isn't running when I jump it. However I ran a meter on the thermo switch and it didn't seem to meet the specs outlined by the FSM. My local Nissan dealer was able to get me another switch and I popped it in there this morning and sure enough the injector still isn't firing. I put the ohmeter back on the new sensor and it's still out of spec based on their requirements. With the No 45 pin probed and the switch body I'm only seeing about 55 ohms. They call for 70-86. The water temp should be below the 58* spec as air temp in the shop is about 55* right now and I haven't run the car in days. Is it possible my new sensor is no good? The thermostat housing was ceramic coated however if I run a continuity test between the thermo time sensor body and a chassis ground it's showing continuity so I think the sensor is grounding properly. What's going on here??

Got it all squared away. The Unilite is going to the side for another customer's 240 project I'm currently working on. I disabled the factory module and installed the XR3000 with no ballast jumper as I believe that disables stock tach function. Everything seems to be working properly at this point. Tomorrow I need to install one of those add on fuel pressure regulators which should be another adventure. This car may benefit from it however since it's got a stroker kit, a larger cam and some head work.

You're correct he probably doesn't....although ignition upgrades to Z cars isn't my specialty either. I talked to him on the phone and we may ditch the Unilite but I do also have an XR3000 here that he is interested in installing instead because of the optical trigger system. Still don't think the fancy doo-dads are needed for his setup but to each their own. I know the 3000 requires disabling the factory module as well which I've done. It does call for you to bypass the factory ballast however which I'm still a bit unclear on how to do.

I did not unplug the old module. It's in the driver area kickpanel correct? I'm installing the Unilite upon request from my customer. He basically came to me with a list of upgraded parts he wanted to install. The ballast that came with the coil has no markings...and if my electrical theory is correct it's just a resistor and can be installed in either direction. The factory ballast has 4 posts while the new one has only 2.

Steve, I installed the ballast that came with the PS20 coil as a standalone ballast for the distributor and that was what was smoking. Which terminal on the stock ballast should I see the reduced voltage one?

So I've been trying to wire this new Mallory Unilite into my customers 75 280Z and I'm a bit confused as I'm finding conflicting information. Along with the Mallory I'm also upgrading to the Crane PS20 coil. Motorsport Auto says to retain the factory ballast with this coil. I did some quick checking and it doesn't appear that any of the posts on the factory ballast get less than 12V with the key in the on position. Am I wrong on this? Also I've read that you must run a ballast that drops the voltage down to the 6-8V range to keep from frying the module on the Mallory...so how do I make this work with a stock ballast that doesn't seem to be cutting the voltage? My new coil came with a ballast that I wired in for now but with the key in the on position it start to SMOKE! Right now I have the distributor wired as such....12V ignition and red dizzy wire to one side of ballast. Other side of ballast to Coil +. Green dizzy wire to Coil -. Brown dizzy wire to engine ground. The timing should be close enough to start however I don't think I'm getting an injector pulse....which I think is due to the stock blue wire being removed from the Coil-. However when I do hook this wire up I lose my spark. What am I doing wrong here?

After talking with Aaron over at Motorsport again I don't think I'm going to be running the XR3000 at all. Apparently there is no real benefit over the stock setup. Does anyone agree or disagree with this statement? Looks like the distributor should be fairly easy to wire up then. Brown to Ground, Green to Coil -, and Red to ballast where the 12V ignition also comes in, then from ballast to Coil +. Now I just need to dig out a test light or wiring diagram to find out which is the 12V ignition wire.

Mike thanks for the tips. I spoke with one of the Tech guys at Motorsport and he said there's no need to change over the signal trigger from the Mallory to the Crane one. I'm working on getting everything into the car now but I'm going to have to figure out which wires from the XR box go to which wires from the Mallory since the color coding will be off now. Any ideas how I can match these up?

Hello everyone. I just joined this site. I own and operate a restoration shop in central NJ and do a lot of work for members of the NJ Z Club. I ran into an issue today that I'm not sure how to remedy if it's even possible. I have a customer's 75 280 here that I installed a warmed over engine into last winter along with restoring everything visually. He has it back to upgrade the fuel and ignition systems a bit. I ordered up a new coil, the Crane XR3000, and Mallory Unilite distributor for the car and was getting ready to install them today. However there don't seem to be any brackets in the XR3000 kit that will install the correct optical trigger in place of the stock Mallory unit. After talking with Crane they said they don't show an install kit for the Mallory 6cyl distributor. Are these parts not compatible or am I missing something here? Is it possible to use the Mallory optical trigger with the Crane box?