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Hello everyone. I知 new to the Z community and have owned my Z for about 8 months now. I have a 2003 350z with 118000 miles that recently started stalling out for what seems as no good reason. Engine mods include Injen COI, plenum spacer, and Invidia Gemini/Cat delete.
It all started when I did my valve cover replacement. I replaced 1 coil pack that was leaking at the seal as well as all the spark plugs with OEM Nissan ones. When I hooked everything back up she ran great! I did the ECU reset and drove 100 miles continuously, doing both highway and city driving. I continued to drive it for the next few days racking up a total of around 200-250 miles. Then one day I pulled off my street and it stalled out and would not start again. After a few more tries it started as nothing was wrong. Ever since that day the car randomly stalls, at idle AND while driving for seemingly no good reason. The car has no issue starting, sounds good and then randomly it値l misfire a few times and then, it dies. Usually after it stops, 90% of the time it値l start right back up, the other 10% it値l crank/no start, and after a few minutes will start right back up. I can稚 find any vaccuum leaks, I have ruled out VVT solenoids, MAF, O2 sensors have proper voltage and fuel trim readings. Engine Idles around 625-650 which seems low. I have no way to test AFR but it seems rich judging off smells and some buildup on exhaust tips (not sure if thats normal when Catless) when it stalls, the oil, battery, and cel light all come on and then turn right back off when started again, also it does not throw a code neither before/after stalling.
I included some screenshots from my OBD reader if that provides any info.
sounds like cam/crank sensor issues. Check everything in the engine bay. Even battery terminals for corrosion or lose wires anything.
This was the first rabbit hole I went down, I actually replaced the battery and terminals as a whole a few weeks back. I致e heard these cars don稚 always throw CEL all the time for crank/cam so I値l look into that
The cam and/or crank sensors can start failing without causing the CEL to come on, so it's best to get the codes read to see if anything is stored. Sometimes when one or more fail hard enough to cause the CEL to come on, it's too late and you're stranded.
If it is, replace with OEM.
As for the idle, it should be 650 +/- 50 rpm, so you're fine there.
A common mistake is to mix up the wiring harnesses for the ignition coils whenever replacing the valve covers, but since you drove for about 200-250 miles without incident, I doubt it's that.
Car stalls randomly at idle or high speeds. Engine runs perfectly fine. Ruled out battery & alternator & belts.
Replaced coil packs and spark plugs just under a month ago. Started stalling last week and has died 4 times since then.
2003 350z VQ35DE 171k Miles
Last edited by lukebpalmer; 05-24-2024 at 02:53 PM.
It sounds like you're dealing with a challenging issue after your recent maintenance on the 2003 350z. Given the symptoms of random stalling, misfires, and occasional failure to restart immediately, several potential causes come to mind. First, check the electrical connections and wiring harness around the areas you worked on during the valve cover replacement, ensuring everything is securely connected and there are no pinched wires or loose grounds. Since the car has no vacuum leaks and you've ruled out major sensors like MAF and O2 sensors, consider checking the fuel delivery system next, including the fuel pump, fuel filter, and fuel pressure regulator. The low idle RPM (625-650) might suggest an issue with the idle air control valve (IACV) or throttle body, possibly needing cleaning or adjustment. Also, given the car's modifications (COI, plenum spacer, Cat delete), ensure the ECU tune is appropriate for these mods, as improper tuning can lead to erratic behavior. Finally, despite no immediate codes, it could be worth having a professional mechanic conduct a more thorough diagnostic scan, as intermittent issues can sometimes be tricky to pinpoint without specialized tools. https://academized.com/buy-essay is exceptional. They Buy Essay Online - Academized provided me with a well-researched and impeccably written essay that exceeded my expectations. The writers are skilled and proficient, ensuring thorough research and coherent arguments. Their prices are reasonable, making them accessible to students on a budget. I'm impressed with their professionalism and would recommend them to anyone needing academic writing assistance.
Last edited by HarperGarcia; 06-23-2024 at 09:18 PM.
04-17-2023, 10:28 AM
Engine randomly stalling
