NewZed Posted August 13, 2016 Share Posted August 13, 2016 And odds are good that the crud in the tank and lines came from water in the fuel. If it got through the filter, the injectors could be rusted. They're sensitive. The injectors are easy to remove as an assembly still attached to the rail. Don't miss the bracket held on by an intake manifold bolt. That's the cause of many bent fuel rails. Quote Link to comment Share on other sites More sharing options...
ericp501 Posted August 13, 2016 Author Share Posted August 13, 2016 No I take it back.. I think its bad gas. Gonna pump everything out of the tank and try again in a bit. Quote Link to comment Share on other sites More sharing options...
ericp501 Posted August 13, 2016 Author Share Posted August 13, 2016 Where are your fuel pressure measurements? Between the filter and the rail. Don't really have a way to measure that at the moment, but I am getting fuel through the return line so its enough to open the FPR Quote Link to comment Share on other sites More sharing options...
ericp501 Posted August 13, 2016 Author Share Posted August 13, 2016 And odds are good that the crud in the tank and lines came from water in the fuel. If it got through the filter, the injectors could be rusted. They're sensitive. The injectors are easy to remove as an assembly still attached to the rail. Don't miss the bracket held on by an intake manifold bolt. That's the cause of many bent fuel rails. I agree, I'm going to pull the line and see if the injectors are spraying at all. If not I'll try running some chemtool through them for the time being, but its likely I'll need all new injectors. Quote Link to comment Share on other sites More sharing options...
ericp501 Posted August 13, 2016 Author Share Posted August 13, 2016 Just noticed my injectors are 3 different colors, tan, green, and I think there was a blue one. Some of the screws came off easy, others feel like they're welded on so they're just gonna have to soak for a while before I try popping the line off. I've heard the 280zx fuel line is an improvement, might just try to score one with some clean injectors on it. Quote Link to comment Share on other sites More sharing options...
NewZed Posted August 13, 2016 Share Posted August 13, 2016 I've heard the 280zx fuel line is an improvement, might just try to score one with some clean injectors on it. Not a bad idea. The 1978 280Z rail is also a direct swap, and one piece. 75-77 are the three piece rail that you have now. The ZX rails will swap but the cold start valve tube will need some bending. Nissan redesigned the intake manifold for the ZX's, although 1979-80 is a transition period for the L28 engine. Not sure what they did for intake there. They can all be made to work. Quote Link to comment Share on other sites More sharing options...
ericp501 Posted August 14, 2016 Author Share Posted August 14, 2016 I pulled all the plugs and put a little gas in each cylinder hoping that would get it started then she'd run from there, even if it was rough, but once the gas in the cylinder burnt up that was it and it died. For the record, this is someone else's project I got for cheap, it has the Ferrari GTO body swap and was pretty much gutted, so I put the replica dash back in and started rerunning the whole wire harness. Even the ignition was locked up so I pulled that and have been just turning the switch itself. I'm sure I'm close and its just something stupid. My ultimate goal is an engine swap anyway, but I'd like to at least get this engine running to I can easily move it around my property till I'm ready for the swap down the line. I really don't want to put much more money into this motor, so hopefully the new injectors do it otherwise the engine swap is going to happen sooner rather than later. Quote Link to comment Share on other sites More sharing options...
ericp501 Posted August 14, 2016 Author Share Posted August 14, 2016 Went out and turned the key one last time today.. sputtered as I feathered the gas, did that weak idle motors do for 10 seconds just as they stall out. I guess its a step in the right direction.. I had put some chemtool into the fuel rail earlier in the day. I'm guessing that helped clean out the injectors a little which makes me think that much more I just have 6 badly gunked injectors. Quote Link to comment Share on other sites More sharing options...
NewZed Posted August 14, 2016 Share Posted August 14, 2016 The 10 seconds then die behavior is actually typical of the AFM fuel pump relay switch not making contact. It's bypassed during Start if you're using the fuel pump relay circuit as it was intended. You can short it or bend the control rod in the AFM to fix it. Quote Link to comment Share on other sites More sharing options...
ericp501 Posted August 14, 2016 Author Share Posted August 14, 2016 The 10 seconds then die behavior is actually typical of the AFM fuel pump relay switch not making contact. It's bypassed during Start if you're using the fuel pump relay circuit as it was intended. You can short it or bend the control rod in the AFM to fix it. At the moment I'm actually running wires direct from the battery to the fuel pump with a manual switch. Can you be a bit more specific about the contorl rod in the air flow meter? I'm not 100% sure which one that is and I don't want to mess anything up. Quote Link to comment Share on other sites More sharing options...
NewZed Posted August 14, 2016 Share Posted August 14, 2016 If you take the black cover off of the side of the AFM and look closely you'll see the tiny contact points for the pump switch. A metal rod closes then when the vane opens. You can bend the rod to adjust it if it's off. But if you have a hotwire with a switch, it's irrelevant at this point. Quote Link to comment Share on other sites More sharing options...
ericp501 Posted August 14, 2016 Author Share Posted August 14, 2016 So it was running. Got some throttle response too but its not consistent and hard to get started and there's no idle at all. Now the stupid Injection relay is making a whining noise and I'm getting nothing.. I'm sure I'm no longer getting pulse, so I just called it a day but at least I'm on the right track. I think I've got about a $250 budget on this engine to get it running right otherwise I'm giving up on making it moveable for now and just focusing my energy on interior/exterior, brakes, ball joints, etc. and just replacing the motor with an LT1 or something. Quote Link to comment Share on other sites More sharing options...
ericp501 Posted August 15, 2016 Author Share Posted August 15, 2016 Update: looks to be starting and has pretty good throttle response, way better then before, so I guess the injectors are getting cleaned out. Main problem now is it wont stay running, no idle at all. I'll feather the gas to keep in running but if I take my foot off the gas it just dies. I unplugged the AFM which seemed to help so I imagine I'll be needing a new one of those. But is there anything I can do for the time being to help keep the car running at idle? Quote Link to comment Share on other sites More sharing options...
NewZed Posted August 15, 2016 Share Posted August 15, 2016 Imagining will cost you a lot of money, AFM's are expensive. Check for vacuum leaks, check the PCV system. Turn the idle speed adjustment screw. The ECU is designed for injectors that flow a specific amount. It doesn't adjust for low flow. If they didn't flow at all before it's unlikely that they're flowing the proper amount now. If you let all six injectors squirt for the same amount of time in to containers they should all squirt the same amount. If there's an imbalance, you have cloggage. Quote Link to comment Share on other sites More sharing options...
ericp501 Posted August 15, 2016 Author Share Posted August 15, 2016 I found a vacuum line under the throttle body that was unplugged. I adjusted the idle screw (All the way in then 6 turns out). I pulled all the electrical components having to do with idle and throttle and game them a cleaning with electronic cleaner. I pulled the cold start valve and sprayed the snot out of it with carb cleaner. I sprayed the snot out of the throttle body internals with throttle body cleaner too. Just started it and it has amazing throttle response and is actually idling! The idle is a little rough, but great that its actually running. When you give it gas it revs up fast and clean with no popping or anything. The AFM is currently unplugged which I imagine has something to do with the idle not being perfect. I'll go plug it back in a bit later to see if it helps with the idle at all.. but for now couldn't be happier. Once I get the master clutch cylinder it I might actually be able to take this thing for a ride around the property! Thanks for all the help guys. I'll keep this thread alive as I improve things. Quote Link to comment Share on other sites More sharing options...
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