the_journeyman Posted September 13, 2011 Share Posted September 13, 2011 Ok folks, hoping to not be a complete pest here, but as I look over this 1978 280Z I've got, I keep finding more and more questions. Bad part is it isn't things that would be covered in the FMS (I have a PDF of it) since it's non-original parts & prior modifications. Ignition stuff: Timing light is simple enough to use, never done it, but after reading the process on here, I won't have any trouble. However, does having the Crane XR700 electronic ignition change that any? I don't *think* I have a vacuum advance attached, but not 100% sure. I'll have to check. If not, is it needed with the electronic ignition? Fuel System Fuel pump clicks loudly, but seems to make good pressure (5psi according to gauge) and seems to supply plenty of fuel. Fuel tank is much newer than the car, so I'm assuming the pump was added with the tank. Fuel Pressure Gauge, I'm assuming has been added. It is mounted a line leaving a cylindrical thing about 3"-4" in diameter that tapers round on the bottom. It's near the passenger side fender, fuel line enters bottom, comes out top. What is that thing? Fuel return line has a valve (quarter-turn on/off kind like a petcock). Completely closed, fuel pressure is 5-5.5psi, completely open, gauge reads 0psi, but car still runs. Pressure comes up as you turn the valve. I have it set where the gauge reads 3psi (about half-way open) since the Mikunis want that pressure AFAIK. Brakes Vacuum line (assuming, coming off top of carb) coming from the 3rd mikuni connected to brake MC. It has a twist-type valve that you can vary from open to closed. Haven't messed with it, but what would its purpose be? Other Air horn & fog lights added, relays added for them too. That's probably a good thing since the horn has a compressor & lights are really bright. Bumper delete has been done, nothing really added except a little thin metal flange added to the rear for appearance purposes. Will it pass like that in NC or am I going to have to find a bumper? Old FI equipment still in engine bay, just wrapped up and zip tied to driver's side fender. Is this hurting anything? That's all for now. Thanks! Quote Link to comment Share on other sites More sharing options...
BluDestiny Posted September 13, 2011 Share Posted September 13, 2011 Fuel tank is much newer than the car, so I'm assuming the pump was added with the tank.Fuel Pressure Gauge, I'm assuming has been added. It is mounted a line leaving a cylindrical thing about 3"-4" in diameter that tapers round on the bottom. It's near the passenger side fender, fuel line enters bottom, comes out top. What is that thing? Fuel return line has a valve (quarter-turn on/off kind like a petcock). Completely closed, fuel pressure is 5-5.5psi, completely open, gauge reads 0psi, but car still runs. Pressure comes up as you turn the valve. I have it set where the gauge reads 3psi (about half-way open) since the Mikunis want that pressure AFAIK. The cylindrical thing on your fender should be your fuel filter. That fuel return line valve is what I'm guessing is an attempt to manually regulate the fuel flow because the car doesn't have any kind of fuel pressure regulator mounted. You should also very thoroughly go through the FSM's wiring diagram and see what FI is not being used anymore and remove it. If it is getting power and sending electricity to the clips or whatever you are asking for an engine bay fire. You should be able to separate the FI harness from the chassis harness anyway. And when I say FI harness I mean the fuel injector clips, MAF clip and most the the extra items on the old manifold. Quote Link to comment Share on other sites More sharing options...
the_journeyman Posted September 13, 2011 Author Share Posted September 13, 2011 The cylindrical thing on your fender should be your fuel filter. That fuel return line valve is what I'm guessing is an attempt to manually regulate the fuel flow because the car doesn't have any kind of fuel pressure regulator mounted. Ok, I didn't realize the filter would be that large, but at least I know what it is and can check it's condition. So, I'm guessing that I should keep the return valve set where I'm getting the 3psi the Mikuni carbs want. I should probably check into a pressure regulator and do the fuel delivery right. You should also very thoroughly go through the FSM's wiring diagram and see what FI is not being used anymore and remove it. If it is getting power and sending electricity to the clips or whatever you are asking for an engine bay fire. You should be able to separate the FI harness from the chassis harness anyway. And when I say FI harness I mean the fuel injector clips, MAF clip and most the the extra items on the old manifold. I'll look at the wad of wires. Whoever changed the FI to carbs rolled the wires up and stuffed them in a heavy plastic bag. I can trace it ALL to one thick wire bundle coming from the driver's side of the firewall, near the bottom. I'll see what all of that stuff is. There are no wires running to the motor itself aside from the spark. Thanks for the input! Every little step helps! JM Quote Link to comment Share on other sites More sharing options...
Miles Posted September 13, 2011 Share Posted September 13, 2011 Post some pictures Quote Link to comment Share on other sites More sharing options...
the_journeyman Posted September 13, 2011 Author Share Posted September 13, 2011 (edited) Post some pictures I'll get on that when I get home this afternoon. Since I'm running carbs, not FI, I'm assuming I would need a FPR for a model that was originally equipped with carbs? Possibly something like this: Holley FPR JM Edited September 13, 2011 by the_journeyman Quote Link to comment Share on other sites More sharing options...
the_journeyman Posted September 14, 2011 Author Share Posted September 14, 2011 (edited) Pics of things: Fuel pressure gauge & what was ID'd as the fuel filter. Lines go from the gauge through the banjos on the carbs and back to the valve with the red knob. The position of the red knob gives me about 2.5-3.0psi. I got an improvement on my plug readings after a short putter through the neighborhood. Vacuum gauge, line runs from 3rd carb to back of brake MC on fender side Overall shot of bay, seems really empty, pass. side Another overall shot, FI stuff is circled in red. Stuff goes in, nothing comes out, so that must be only FI stuff, and the chassis wiring moved Found this under the rear carpet, bet that bottle of inflator is past its expiry date Hope that helps! The vacuum advance is still hooked up, pulls of the 1st carb. If it is hooked up with the electronic ignition, is that good or bad? Can I just unhook and see what happens or will I damage something? JM Edited September 14, 2011 by the_journeyman Quote Link to comment Share on other sites More sharing options...
the_journeyman Posted September 14, 2011 Author Share Posted September 14, 2011 (edited) Oops. Duplicate. Edited September 14, 2011 by the_journeyman Quote Link to comment Share on other sites More sharing options...
Pharaohabq Posted September 14, 2011 Share Posted September 14, 2011 You overall short, the one with stuff cirled in Red. That could be AC stuff, Normally the AC pump would be on the driverside below the manifolds. It's really hard to see in your picture. though I don't see any connectors by your tranny tunnel so it's hard to identify what's there. A little better pictures might help. The passenger side is normal not to have much there. I've been people move the coil and setup MS and such on that side. Alternately it is a great location for that Water2Gas Hydrogen setup, if you believe in that. Quote Link to comment Share on other sites More sharing options...
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