Cars interesting problems- need ideas

mike12002us

So my car has been having some interesting issues. I have searched the forum extensively and been trying to get ideas as to the issue. Ill go through everything in a time line to help. To start I have a 2010 370z sport manual. Just hit 90k miles and had plugs changed 25k miles ago. I keep it up to date with servicing. Here is my story.

starting out: I had an Injen exhaust, G3 intakes, stillen pulleys and did an uprev tune. The car ran perfectly.

then: I added test pipes and a Stillen 25 row oil cooler and the car felt even better but waited for a new tune until I got the new ported plenum. No issues with just adding TP. Got the CNT Resonated btw.

then: Installed Stillen grounding kit and drove to tuner to have upper ported plenum installed and get a new tune. - car drove ok for the ride home but I never got on it to see what it felt like as it was raining and traffic would not allow for it.

Home: After a few days I noticed that my car would run perfectly when first started and the throttle response is amazing. I can really tell the car has power in 6th gear ( for reference ill be using 6th gear as my guage) The car would then intermittently start acting up. I would be at a stop light and floor the gas and it would take a few seconds floored for it to come up. After 2k rpm it would rev quickly. I also noticed in 6th gear where I normally would pull on the freeway that my power had dropped considerably.

Back to Dyno: I took my car back to the tuner and had it retuned thinking that the timing was too far advanced. We saw on the dyno (the problem luckily recreated itself) that I had no power until 2k rpm then it would jump up. Got the retune and the car felt ok.

Home again: after a few weeks the car started to act up again. The weather had changed from scorching hot to warm and that seems to help the issue. Also when the oil goes over 180 degrees it brings the problem on. This maybe just perceived and not fact for all instances though. It seems when its warm out and the oil hits over 180 in oil temp is when it happens??


Now: I have now received a tune via email going to stock timing on the car and it still does the issue.


I need help figuring out what is going on. I have taken off the throttle bodies and cleaned them as they were filthy. I have been informed that it sounds like a:

1.Vacuum Leak in plenum or hoses going to it
2.Tune issue
3. Sensor issue.
4:?????

I have data logged the car and all of the sensors seem to be fine. I am going to pull the upper plenum off and see if I can find any leaks as wel as take it to be pressure/smoke tested. Im thinking of putting the stock tune on the car to see if the problem goes away. If it does its the tune.

I am just trying to see if ive missed anything and pick your brains a little. Im so frustrated with this. Its been 2 months of issues now. The tuner has been more than helpful but they are 6 hours away and I cant go there every week.