SmokeyRoach

FIXED!!! Changed #6 injector and bamm! Runs like it should now. The injector WAS stuck open thus causing the cylinder to flood out thus killing the spark. This is the black and white fact and proof this can happen. Changed it out for now with a GP Sorensen P/N 800-9208...AutoZone $44. Looks like eventually I will upgrade all the injectors and fuel system since I am in the full restore mode. However thanks for all the help and the healthy discussion!

Gents, I will finally be able to get back to this over the weekend and give you guys an update on what I find. Just a note, firing order is correct, all plugs, wires, dist cap/rotor etc are new and replaced in an attempt to solve this. Based on everyones comments here "which btw is great feedback" I will replace the injector and go from there. From what I have troubleshot on this so far it is the only thing left that I have not changed and makes sense if its stuck open. The good thing is that I have a spare fuel rail and injectors. I will change out #6 injector and update you on my findings. As for upgrading the Ignition/EFI system...I would love to one day and probably will, but there is no reason to do that now and drop $ before finding the root problem. Thanks Bill

Wet with fuel.

All, For some reason my #6 cylinder is not firing. To start the plug is wet when pulled out after running on the remaining 5. Injector is firing, spark is good on #6, compression is at ~178-180 on all, timing is right on. All my checks so far check out but it is still not right. Any ideas how to further troubleshoot this? Thanks 76 280z Stock motor

Sorry, its a 5 speed, 76 with original engine. I looked at some old pics and saw that one of the ivory colored wires goes to the water temp switch. These wires are all part of the same bundle and go to a 3 connection connector that contains a red wire and 2 ivory wires, looks to be "C14" on the 76 wiring diag. Just need to know which ivory wires goes where since they are very close in color if not the same. Thanks

All, I have two "ivory" wires going to the water housing. Where do they plug into? The one Red wire is on the temp sensor and there is a black wire also that is not connected? The two ivory wires the PO cut off and I need to figure out where they hook. Anyone know where these go? Thanks

Yes got the FSM on CD and wiring diags. Fusable links are good, The ignition relay does come on and is good, I bet its something right in front of mine eyes with the + wire between the ON position and Pin 71 (86c) of the fuel pump relay or the ground to pin 72. I will let you guys know next time I get under the dash...BTW the motor sounds awesome and runs great!! Cant wait to drive a Z again. Thanks

Well I was wrong, new ignition switch is not it...my bad logic. All EFI harness checks "referance FSM 76 Z" and funtional tests check out except for the Power Line Circuit. Pin 10 on the ECU should show 12V with the ignition switch in the ON position. I dont see 12V on pin 10 of the harness. The solution is to referance the circuit in Fig EF-50 of the FSM. This shows the componets in the mix here are Battery, Fusible Link, Ignition Switch, Fuel Pump relay, harness and the Control Unit. All these items seem to check out even the wiring both Pos and Grounds. I have gave up so your help is much appreciated. The engine runs when I hold down the secondary fuel pump relay contacts "the one the latches the other after the key is released from the Start postion. So with that said is there another item I'm missing such as the ECU needing to see RPM's etc. Thanks in advance I know I'm missing probably the most basic thing here but I now need a 3rd eye ball... Bill

Thanks for all the help gents! After getting the FSM on CD etc and a full fuel system/control unit test it appears that the ignition switch is intermittant in the On postion thus causing the fuel pump relay to de-latch here and there. I would have spent days more except I found it by removing the relay from the metal can around the fuel pump relay and watching the coils energize. I recall back in 89 when I last add a 280z I had the same problem should have know better... Bill

Hello all, Can I wire the fuel pump on my 76 280z through a seperate switch from the battery to the pump for test purposes to get the engine running? ..heres why.... I only get power to the fuel pump while cranking..i understand this is correct and is due to the airflow sensor and that the engine only turning will produce power to the pump...all good with that. Well mine does not seem to continue to run "the pump that is" and thus no fuel to the engine, Ive given up. Since I will be doing a full restore on this car in phases and the fuel system will be replaced I'm not going to try to nick pick it apart but wanted to get it started to check through some things, I know it runs. Thanks for your help, Bill