stravi757

I still havent found anything conclusive. I did remove/pull the pins from the connectors of the EFI Main Relay and the fusible links. They were a little corroded but not badly. They all tested fine prior. Since I cleaned them the car has started without issue. I will find out through time if it corrected the problem.

yes, and also swapped it out with a know working spare I grounded the negative coil wire with the ignition turned on, and the injector will open(confirmed) every third tap. I tried this when the car was not starting by cranking.(edit, fluke test due to intermittence) EDIT. I tried grounding the negative coil wire again when the problem occurred, and the injectors were not opening every third tap ( this is the difficulty with intermittency) I tested the negative coil wire(disconnected from the coil post) for continuity to ECU Pin #1, and it read zero resistance. It was reading correct voltage to pin #1 when given power as well. Im confident the signal to pin #1 is fine. My next step is to try and ground the injectors from the ECU connection manually to see if that will fire the injectors. Im waiting for the problem to come back to test that...

I do not have the cold start valve or thermo time switch hooked up.

So It turns out the problem was not solved. It has come back. I am still struggling to figure out whats the problem. The problem continues to persist the same way. The injectors intermittently wont open open while cranking(tested with noid light), once the engine is running it stays running. It will start right away If you push start the car. I have tested the ecu pins and they all check out fine 12v at pin #1(negative coil) I immediately check this wire for power when the engine decides to not start 12v at pin #10(ecu B+) 12v at all injector pins 12v at pin #4 - When IGNITION is in the "start" position (start switch enrichment signal) harness ground wires all have continuity I have tested with a couple different ecus, no difference.

I found the problem. Zed Head sent me in the right direction when he recommended looking at the coil wiring. Years ago I cut signal wires to the distributor on the main harness. I crimped them back together but not very well. the wires were able to pull out of the crimp by hand. I put the wires back together again and the problem has gone away. lesson: young self did things inadequately, those problem will haunt you years later. Thanks for all the help everyone.

I tried using a different coil and a spare ignition module with no luck. I will track down the positive coil wire though. My spark does seems a little weak(yellow, not blue with either coil). The ignition module contacts look very clean but it wont hurt to spray some cleaner on those too. Interesting problem. I had my stock switch begin to go out a couple years ago. which I have replaced and it would not make contact with the start signal vs. losing contact with the "ON". I dont think this is my problem though because my coil is making spark still. I tried using a spare ignition switch anyway too with no luck. thanks for sharing the video. I learned something new! I tried putting electrical tape over ecu pin #4 to try and "replicate" a push start scenario today and it didnt work. just an experiment I thought was worth seeing out when I got home from work.

Hey. I have been struggling to trace down for some time an intermittent issue with my Z. The engine runs perfect besides this issue. Not a hiccup. It makes great smooth power, passes smog Extremely well, idles well, it basically runs exactly the same it has for the last three years except for this recent issue. Its a stock 1978 280z which I DD . The only modification that comes to mind is I have safteyhub 150 I installed years ago. Problem: The Engine will intermittently not start(it doesnt matter if its been cold and sitting or warm). It started happening months ago, It always starts back up, but the problem has progressively become frequent, and it takes longer too start when it does happen as time goes on. I have traced down the problem to this. The injectors are not clicking while the turning the starter-motor.( I get spark, starter motor turns totally normal as well ) But heres something interesting. I can get the engine to run When the intermittent problem occurs by push starting the car. So its only while the starter-motor is turning that the engine wont start. I thought that was weird. I tried to think of why that would happen. The only idea I have had is, that the START signal from the ignition switch wasn't going to the #4 ECU pin. I checked and It is getting 12v at the pin. (NOTE: I have also tried things like changing out the ECU and various other sensors which I have replacements of. ) I did notice that when I turned the ignition switch the START position with the starter motor connected and cranking, my voltage reading at Pin #4 was 9volts. Is it possible that is too low and is preventing the ecu from firing the injectors? The Battery is fairly new and doesnt seems to have any struggle cranking even though the voltage number is kinda low. Any help would be great. I have been thinking and checking things longer than I can make a list of for weeks now. Hopefully I have described the problem well enough for some insight. Also Its been a while since I have posted, If there is information you think I am missing to make this post more useful, let me know, thanks.

Thankyou!

hey there, I am looking to buy some bullet connectors from http://www.vintageconnections.com/ They have two different styles of bullet terminals and Id like to know which one to buy. Antone know what size we have in our z cars? 3.5mm or 4.0mm?