So my 1986 300zx with 160k miles manual transmission, has been having a low idle issue as soon as you turn on the car, I changed the spark plugs and wires, including distributor rotor and cap but nothing has changed. Any idea where the issue stems from?
Probably a good place to begin is cleaning the throttle body, AFM/MAF, and IAC (Idle Air Control) valve.
Thanks!
common VG engine issues are EGR valve blocked, solenoids on the idle control valve could be faulty, fuel injector clean/service, fuel pressure sensor check for a broken wire or plug, check your timing with the distributor on this engine there is and adjustment screw. check air flow meter. if you have a scanner you will need and OBD reader, not an OBD 2
also check air regulator valve to see if its working or corrosion around the plug, check valve if it is stuck closed.
Check fuel pressure, then throttle positioning sensor. $50 for a new one.
Thank you!
are you refering to no cold start idle where the engine runs at a higher rpm until the ecu re adjusts to a lower idle when heat starts to flow through the engine? being a Z31 300ZX i assume you have the early type VG30 non quad cam type?
@scotty_64 I start it on a cold start and the car is on low rpms and instantly starts shaking.