Guest cantstopdriftin Posted April 19, 2005 Share Posted April 19, 2005 ok, heres the deal. car is 76 280z efi. ran until parked ~6months ago. car cranks and sparks fine. i think im not getting any fuel. i put in 5 gallons of fresh gas because the gauge said there wasnt enough to reach the E mark. now ive heard that the fuel pumps on these cars do not come on unless the engine is running. what should i do to get this thing started. can i prime it by removing the fuel lines in the engine bay and squeezing some gas in. i have to move this car first thing tommorow morning since i already bought it and its getting towed from this guys apartment if its not gone. please any help would be good. and yes i searched. Quote Link to comment Share on other sites More sharing options...
Guest cantstopdriftin Posted April 19, 2005 Share Posted April 19, 2005 <------ also ive posted a dozen times yet my post count is that....hmmmm Quote Link to comment Share on other sites More sharing options...
Jolane Posted April 19, 2005 Share Posted April 19, 2005 The problem that I had with my 280ZX when I ran out of gas once was very similar. My ZX did not have a schrader valve on the fuel rail to bleed the air out of the system, so basically the fuel rail filled with compressed air, with no way to get out. What I had to do was pull the return fuel line off the fuel rail (loosen the hose clamp), and bleed the air out that way. Be careful, because when you pull it off, you may get fuel shooting out everywhere. Watch your eyes. I would then turn the ignition on (don't try to start it though). This should turn the pump on momentarily (a few seconds), then off. Put a spare fuel line onto the fuel rail, and the other end into a fuel can prior to doing this, you will probably get fuel out. If you get a nice stream out, hook the line back up, and try to start it. The return line is the one not running from the filter. It runs from the fuel rail back to the tank, and was smaller in diameter on my ZX. Good Luck, I hope this helps, Joshua Quote Link to comment Share on other sites More sharing options...
evildky Posted April 19, 2005 Share Posted April 19, 2005 the fuel lines have a return so any air in the line is gonna get sent back to your gas tank a schradervalve is for testing and releaving pressure when servicing, as for the fuel pump it will come on when the key is rotated to the run position but will not stay on unless the car is runnings, rotating the key on and off a few times will get the lines good and full of fuel, you'll want to listen carfully of have someone with their head under the car or their hand near the fuel pump to find out if it's coming on, if not check for voltage while rotating the key on and off, if no power check the AFM door, if it's stuck open the fuel pump will not turn on Quote Link to comment Share on other sites More sharing options...
technicalninja Posted April 19, 2005 Share Posted April 19, 2005 The fuel rails can have a lot of air in them which can be difficult to purg. 75 and 76 Zs ran the fuel pump circuit through the AFM (air flow meter) disconnect the boot to the airfilter and move the flap a little, you should hear the pump run. 77 and 78 Zs had a double relay set up to only allow the pump to run when the alternator was making power and the oil pressure was not zero. Disconnect alt plug (two small wire in a plastic housing-just need to pull it out of alt-no tools) and disco oil pr send unit. this will trip the relays. I gave you both methods as this changed late in 76 and your car might have either system. Fuel pumps that sit for a long time can "lock up" especially old pumps. after verifing power to pump (12 vlt tst light to non black wire at pump-power wire is green most of time) lightly rap pump with small hammer or handle end of screwdriver to jar it loose. pump is audible when it is working. get power to pump, get pump working, allow to run 2-5 min (with out trying to start car)to help clear air bubble in fuel rail. I would then spray a small amount of Berriman's B12 (or other carb cleaner berriman's seem to work best for this) into intake maniflod at vacuum line fitting for fuel pressure regulator (intake manifold side) only need a 2-3 second spray.Reconnect vac line and start engine immediatly. As long as the engine is mechanically sound and you have spark any engine will run on Berrimans. After you get it lit you can keep it running by spraying B12 (slowly and carefully- use the red tube to get it well into opening- spraying berriman's at any running car can be a fire hazard-be safe) into entry of AFM. After 15 sec of running try to let it run itself. If it starts to die add a tiny amout of B12. The lines from the injector to the rail can take as much as a minute to clear all of the air. The engine will first run poorly by itself getting progressively better as each injector clears. The earlier post about fuel run in the on position is correct for later GM cars which prime the system for 5 seconds in the initial key on position. The early Z (up to 90) did not have a prime circuit and had check valves in the output fitting of the pump to hold system pressure until the next start. Years ago Nissan sold just the fitting $ 8 which was an easy sell to the Z customer when their car did not start instantly on crank. Nissan stopped selling this part and you could only get entire fuel pumps for $200. I would not replace a pump which lost its pressure hold feature as the cars would start after 5 seconds anyway. Because of this early FI problem GM came up with the 5 sec fuel pump run at first on position. Hope this helps Rick Quote Link to comment Share on other sites More sharing options...
Guest cantstopdriftin Posted April 19, 2005 Share Posted April 19, 2005 thanks for the ideas so far. will be up brite and early to go over there and start working on it.. wes Quote Link to comment Share on other sites More sharing options...
Jolane Posted April 19, 2005 Share Posted April 19, 2005 evildky, While it seems that the air would simply go back to the tank, remember that it must first get past the FPR, which is ~36 psi. That means that the air compresses a lot, and can be hard to remove. I just know what my experience was the one time I ran out of gas...what a pain. I also had to use the shrader valve on a Ford ranger once to bleed the lines after my friend ran out. Maybe the Z can purge the lines another method, I don't know how though. technicalninja, My 83 did have a prime circuit. I could audiably hear the pump run with the key turned to run for a few seconds, then shut off. I think it may have something to do with safety in case of an accident. The pump will not run continuously unless the engine is running, otherwise it will shut down. I assume this to also act like a prime circuit. Again, this is what my stock 83 did. Joshua Quote Link to comment Share on other sites More sharing options...
Guest cantstopdriftin Posted April 20, 2005 Share Posted April 20, 2005 well i got the car started, it appears that it just took quite some time for the fuel to get from the pump to the injectors, drained the first battery and by time i put the second one in the car started. thanks for all the help. wes Quote Link to comment Share on other sites More sharing options...
Tim240z Posted April 20, 2005 Share Posted April 20, 2005 <------ also ive posted a dozen times yet my post count is that....hmmmm Any posts made to the Non-tech forum do not add to your post count. Quote Link to comment Share on other sites More sharing options...
Guest cantstopdriftin Posted April 20, 2005 Share Posted April 20, 2005 ahh i see, damn newbs like me Quote Link to comment Share on other sites More sharing options...
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