Nissan 370Z Forum - View Single Post - Car is not running right. Rough idle and misfiring under acceleration.

Wilson2608 · 01-09-2019, 10:16 AM

I have updated this post because I still have not been able to get the car right. I have tried numerous things and nothing has changed. If you have any suggestions please feel free.. Thank you.

What I have tested/eliminated:
Cats
Fuel pump
Injectors
Coil packs
Spark plugs are good
Air filters replaced
MAF and TB cleaned
PCV valves cleaned.
Checked for vacuum leaks
Replaced valve cover and spark plug gaskets( though for sure that would fix it as there was oil alll over spark plugs )

As i stated before I checked the spark plugs, they look fine and they have about 55k miles on them.

I’m making this post in hopes anyone has any other tips ideas. I’m kinda at my last ditch effort here. Gunna get my boost leak tester from 300zx to be 100% sure there’s no air leaks.

Hello everyone, I have a 09 370z (mods in signature) and am having a issue with idle and WOT acceleration. No check engine light and no pending codes besides random misfire. Once car is warmed up it sounds like the engine is misfiring at idle, i can feel it shake the car very slightly every time it happens and it’s pretty consistent. Under WOT the car will be pulling smooth up until about 4-5k then it starts to break apart. If i keep on the gas it will break apart then pull smoothly again and it continues to this back and forth. I’ve check my air filters, cleaned the MAF, and MAP sensor. Fuel pump was replaced 35k miles ago and spark plugs changed out about 45k miles ago. Was going to check fuel filter but all it is is a black mesh piece attached to the fuel pump assembly. If anyone has any idea please post them.

01-09-2019, 10:16 AM	#1 (permalink)
Wilson2608 Enthusiast Member Join Date: Dec 2014 Location: Nashville Posts: 301 Drives: Nissan 370Z Sport Rep Power: 10	Car is not running right. Rough idle and misfiring under acceleration. I have updated this post because I still have not been able to get the car right. I have tried numerous things and nothing has changed. If you have any suggestions please feel free.. Thank you. What I have tested/eliminated: Cats Fuel pump Injectors Coil packs Spark plugs are good Air filters replaced MAF and TB cleaned PCV valves cleaned. Checked for vacuum leaks Replaced valve cover and spark plug gaskets( though for sure that would fix it as there was oil alll over spark plugs ) As i stated before I checked the spark plugs, they look fine and they have about 55k miles on them. I’m making this post in hopes anyone has any other tips ideas. I’m kinda at my last ditch effort here. Gunna get my boost leak tester from 300zx to be 100% sure there’s no air leaks. Hello everyone, I have a 09 370z (mods in signature) and am having a issue with idle and WOT acceleration. No check engine light and no pending codes besides random misfire. Once car is warmed up it sounds like the engine is misfiring at idle, i can feel it shake the car very slightly every time it happens and it’s pretty consistent. Under WOT the car will be pulling smooth up until about 4-5k then it starts to break apart. If i keep on the gas it will break apart then pull smoothly again and it continues to this back and forth. I’ve check my air filters, cleaned the MAF, and MAP sensor. Fuel pump was replaced 35k miles ago and spark plugs changed out about 45k miles ago. Was going to check fuel filter but all it is is a black mesh piece attached to the fuel pump assembly. If anyone has any idea please post them. __________________ Stillen G3, z1 Intake Manifold, Stillen Headers, Z1 HFC's, Stillen Catback. 330whp 267 ft- lbs tuned at Z1 motorsports. Last edited by Wilson2608; 09-18-2020 at 08:18 AM.