car turns over but wont start. 78 280z please help!

[Nightscraper]

i just recently came across this problem a few days ago and have been scratching my head as to the answer. the car was running fine then all of a sudden sputtered and died completely, i pulled it over checked the wires to see if anything disconnected nothing was so i started it up again and it worked drove a bit longer then it died again. checked once more found a lose sparkplug (it actually separated on the distributor cap) fixed that with my crimps and such. and it would not start after that. any help as to where i should look? im currently waiting on my service manual to come in but have alot of schematics on my comp if any one can help.

[SteveJ]

Fuel, air, spark & timing. One or more aren't functioning right. While you're waiting on the hardcopy FSM, download one from the link in my signature and start reading. Meanwhile, it sounds as though your sparkplug wires and/or distributor cap might need to be replaced.

[Nightscraper]

thanks ill start looking

[jimbob_racing]

Check all the connections under the hood. My '75 would act up periodically from no starts to running very badly. Turns out all the electrical connections under the hood were corroded badly. I spent the day with contact cleaner, a nail file and some dielectric grease and it runs great now.

[Nightscraper]

ok ill take a look at those as well thanks for all the help!

[Nightscraper]

just cleaned the contacts and tried starting it up found no spark so going to change the cap and rotor and see from there.

[SteveJ]

Follow the guide on page 43 of the EE section of the FSM to start.

[FastWoman]

Check your fuel pressure when your engine dies. When my fuel pump was failing, it would generate adequate pressure until it heated up. Then it would fail... and then be normal again after it cooled down. Also check the wiring harness connection just inside the passenger firewall. The fuel pump connection is inadequate and can arc and fail. I fixed mine by snipping the wire out and connecting with a bullet connector.

[grantf]

just a quick suggestion: make sure you have good conections and a good ground to the ignition control module, located above the fuse block, passenger side. Sevice manual: http://www.xenons30.com/reference.html

Edited January 13, 2012 by grantf

[Nightscraper]

went through the ee on the fsm and started taking it by sections starting from battery to coil and found that that was good tried for a spark from there and got nothing so i checked the distributor cap and rotor (they were pretty bad) replaced those then i took off the coil and tried to test it and got no spark so trial of elimination huh? for testing it i took it out attached it to a battery pos to pos neg to neg and got a jump cable and rubbed it on ground to see if i could get a spark and nothing (found that on youtube) is that the correct method to test it?

[SteveJ]

The coil has no moving parts. It's a simple step-up transformer. If you look on page EE-40 of the FSM, it gives you the resistance ranges for the primary and secondary coils. If the resistance is out of tolerance, it could mean a short in the coil (low resistance) or a broken wire (high resistance).

Note: The resistance ranges are for a stock type coil. If you or a previous owner changed to a 3 Ohm coil and removed the ballast resistor, the resistance range will be different at least for the primary side of the coil. You would have to find the range from the manufacturer of the coil in that case.

[FastWoman]

If you physically removed the coil, you would have to jump a spark between a wire hooked to the coil's output and the coil's mounting base.