280z idle problems

[needmydatsun]

hey guys, im new here and i have a question. i just got a 78 280z and its my dream car so im really excited that i finally got one (im 16). i got the car for $1,000 and everything is there. it drives fine and everything exept for the idle. when i start the car it idles perfect and starts with no problems, but after the car warms up it starts idling all funny like its about to die. my dad said it might be the throttle valve switch or it might be a vaccum line but neither of us are sure. i cant pinpoint problems but once i know what the problem is i can fix it. so if anyone has any ideas or suggestins of what it might be i would really apreciate it.

thanks guys

[BBISHOPPCM]

Try replacing the oxygen sensor. I believe the earlier fuel injection systems work like this (someone please correctme if I'm wrong) When cold, The fuel mixture is determined by the mass airflow sensor and coolant temp sensor; in this state, the mixture will be slightly rich. This is called "open-loop mode," it uses a predetermined mixture that will allow the car to run until it warms up. Once a higher temperature is acheived, the computer turns to the oxygen sensor to determine the actual burn quality, and adjusts the mixture as needed (closed loop mode). Theoretically, if the OXS is giving false readings, the computer will compensate incorrectly. If there are no readings, the computer will be forced into a "fail safe" mode. Is this right?

[needmydatsun]

checked the oxygen sensor and my chiltons says it needs to be replaced.thanks for the tip

[Stealth-Z]

checked the oxygen sensor and my chiltons says it needs to be replaced.thanks for the tip

78's do not have Oxygen sensors.Here is a link to the factory fuel injection manual. Right Click and save ashttp://www.fairladyzg.com/PDF/...k.pdf

[needmydatsun]

chiltons said that if no light turns on under the dash that the oxygen sensor is messed up and no light came on so i figured it was messed up but i never actually looked at the sensor itself, i looked for it but couldnt because its apparently not there. i guess i'll keep trying to figure it out.thanks for the link and that info stealth-Z

[evildky]

on the bottom of the thermostat housing there are a few sensors, the one with 2 wires is the one that tells the CPU the engine temp, replace it, it might be the same as the later CHTS found in the head of the alter cars, it can aause you to run pig rich once warmed up

[needmydatsun]

do you know what that sensor is called and where i can find one?

[evildky]

I assume it's still calledthe CHTS (Cylinder Head temp Sensor) I think it's the same just a different location

[needmydatsun]

thanks

[needmydatsun]

i fixed the vaccum leak i found and it still idles kinda crappy but not nearly as bad i think it might be a connection to one of my fuel injectors because a couple of them have fallen off before, i have them taped on right now. thoughts?

[cpt jack]

78's do not have Oxygen sensors.Here is a link to the factory fuel injection manual. Right Click and save ashttp://www.fairladyzg.com/PDF/...k.pdf

hahahahah 02 sencors i own a 280zx and i dun need that pos my car actully runs better... LOT! thank god for oldskool

[BBISHOPPCM]

hahahahah 02 sencors i own a 280zx and i dun need that pos my car actully runs better... LOT! thank god for oldskool

WHAT?!?!?!?

And I do believe your issues are caused by/not helped by poor injector connections. How are the contacts? any corrosion on the terminals? If so, you would benefit from replacing the connectors by splicing on new ones (not sure where you can get new ones).

[needmydatsun]

not really, a little, but ive been looking for connectors and i doubt schucks or westbay would have them so if anyone knows where i can find some PLEASE help

[evildky]

summit sells them, but your stuck paying their oder processing fee, msa sells them but are a bit pricey, I've seent hem on ebay, diyautotune.com sells them, sparkandfuel.com sells them, heck look though the adds at diyefi.com and find plenty of sources

[needmydatsun]

thanks