FairAbrocoma

Backfiring consistently even. The car is turning over but not firing up.

I'm at the end of my rope here. I have a 1978 280z and I am having issues getting her to start. I have a spark at the spark plugs due to a tester I bought. My fuel pump works. It is timed correctly because I rotated the engine to TDC at #1 cylinder then put the dizzy back in it's place. All the spark plugs are timed in order at 153624. I took out the cold start valve and made sure it was spraying gas, it does. Although, upon putting it back in the rubber seal broke so now it sprays a little gas everywhere. I tried to circumvent this by just buying starting fluid and spraying it in the intake. Still no dice. My last option is to see if the fuel Injectors are spraying efficiently but I'm pretty sure the car should still start just from the fuel from the cold start valve and maybe die later from the fuel Injectors not functioning. But I'm not even getting that. Tell me if I'm wrong or anything you all can suggest. Everything electrical works as well because I did all the diagnostics for no start in the EE section of the FSM.

That was the next thing. And it smelled like good and clean gasonline. And if it dies after the starter fluid then it's a injector issue correct? Not supplying enough gas for idle?

Good point. Well redact that then lol. I also installed in the spark plugs I bought a while ago just to humor myself and still no dice. I had my gf start it while she pressed a little on the throttle and nothing. A little backfire, but nothing indicating the car has any intentions of starting.

Gotcha. I pulled the cold start valve, and look and behold it works. But life caught up to me and I cannot test the injectors at this moment. But the valve is definitely getting the signal from the thermometer to inject gas.

I have not done much in preparation to start it. The only thing that I've done to start is putting new gas in it and buying it a new battery because the seller did not provide one. Other than that I have replaced most of the ignition systems. I have replaced the ignition coil, distributor and cap, new sparkplugs (which have yet to be put in), new sparkplug wires, and a new ignition control module. The testing I was referring to was the testing procedure in the FSM about an engine not starting, in the fuel section on page EF-22. In that section it says to check certain item numbers in case the engine doesn't start. In this case the items are: 1 - 3,5,6,7,8 2 - 1,2,3 3 - 1,3 In the first string of tests it asks to check for continuity at certain pins on the ECU. I set the multimeter I have to the OHM setting and got continuity readings for all of the test items for Test 1, which were things like the ground and the thermontine switch. They all had continuity and checked out OK. For test 2 it asks to check for voltage at the these pins, which correspond to each of the injectors, the power line, and the revolution trigger signal. These checked out as I had battery voltage for all of these. For test 3 it is the same thing and it tests out the starter signal, and the cold start valve and thermotime switch. This checked out ok as well. As for the history of the engine, I have no clue. I asked the PO if it ran and he said it did a while ago and the only thing that was wrong was that the car was that it "shifted weird". Likely a new clutch. Will update with the cold start valve test though and injectors.

A bit of an update. Turns out my pump is fine and it does actually run at start like you said. When I disconnected the cold start valve harness ( a little too easily I might add ) and the starter motor I could hear the fuel pump pumping gas. But still with no start and presumably gas, no start. I did all the electrical fuel tests at the ECM and everything checked out ok. I will start things by testing the cold start valve and testing the fuel injectors. I did find resistance for the those at the ECM which means continuity but I will check for functionality as well. If those check out, I will check the fuel filter and flush out the fuel system to get any water and or bad gas out of the system, also to see if gas is even getting the engine I just put in new gas already but it may have mixed with the old. What do you all think?

I will try the oil pressure trick as soon as I get off work. I believe I have a problem because the car obviously wont start, it turns over and I have spark going to the plugs, but no dice. And when I turn the key to the ON position, the fuel pump is not priming. Not even turning on. I figured it was grounding issue because 12V are intended for the pump at the relay, which means that the oil pump check, as well as the alternator signal, are allowing 12V to be sent through for the running and priming of the fuel pump.

I have recently taken ownership of a 1978 280z, original motor and everything. But, I am having a power issue with the fuel pump wiring. At the relay, I am getting 12V into the relay (the green/blue wire), but only about 3.4 volts out through the other green blue wire. My question is, is this a simple grounding issue, if so, where it the ground for the fuel pump exactly? I have looked at the wiring diagram still my eyes crossed and I have determined that the fuel pump is grounded inside of the ICM with a few other electrical items. So would my best option be to just cut the grounding off before it splits and just screw it onto the chassis for a ground? Would love your guy's help with this. Also, I jumped the fuel pump just to determine if it would work with 12V and it does so at least that works.

I did. Getting random amount of volts but it's coming through

It's a 78. I replaced the coil because I wasnt getting resistance between the two poles. And I used a multimeter for the coil and a test light for the spark plugs.

Just recently bought a 280z and was trying to get it up and running again but ran into a few problems. I'm getting no spark to the engine. I have replaced the ignition coil as the previous one did not carry resistance. Also the distributor rotor spins and the connections do not seem to be corroded. But still no spark to the engine. When hooking up a spark plug tester I'm getting no light which I am told means a ignition system issue. My last resort is purchasing an ignition control module but, ya know, it's expensive. Would like your guys' take on this. Any help is appreciated. And btw it cranks and everything. Nothing timing related, she's trying her hardest.