I just got my 350z back from the shop after install of jwt 272 cams, rev up oil pump, new valves/heads, 550cc injectors, and walbro 255, and a full new timing chain kit. My car won’t run, it starts up but immediately chokes and dies. I can keep it alive if I play with the throttle but it is very rough. My tuner has sent me 3-4 different base tunes trying to get it running/figure out the problem. (No luck)

My data logs say the car is running stupid lean... like air fuel ratio of 30 and at some points it even read as high as 97, I don’t think that’s even possible!!! What the hell?!?!? But my car should be running rich because of the much larger injectors, and when it does start up it smells rich. Car also has code for random multiple misfire. I checked all coil packs and plugs and they are good and flow tested my injectors and they are good as well.

I know my upstream O2 sensors have been bad for a long time but it’s never caused any issues... maybe this is one kind of crazy o2 sensor thing or something??? Anyone have any idea or recommendations?... after $4,000+ I’d really like to have my car running

if you’d like to see the data logs, or videos of what’s happening, or talk to me directly,
pm me on Instagram @Pearly_z33
Any insight helps...

 

Tow it back to shop.

 

My thoughts are, why did it leave the shop?

 

because it was expected to not really run with the much bigger injectors and all the additional work that was done, it was towed home where the plan was to put a base tune on it so it would run proper with the big injectors and cams.

 

How did that work out for you?

 

[QUOTE=travlee;11033152]How did that work out for you?[/QUOTE

Clearly I’m having issues, any help with ideas of what may be a potential cause for what’s going on would help greatly. Please and thanks.

 

[QUOTE=Freudenthaler;11033156]
this should help ya some

https://bfy.tw/OrNG

 

What are you using to tune? Are you able to tune it yourself?

 

The problem you are having can be caused by so many things that we can't really help you without logs (what ECU are you using?).
The problem can be a vacuum leak or very low vacuum. Can also be that the new injectors arent setup correctly in the ECU. Did the tuner changed the dead time, flow rate etc.
Only a tuner can help you with this im afraid.
The one thing you can ask to your current tuner if he can raise the idle RPM to 800-900 and see what that do.

 

Pat at limpmodetuning is remote (email) tuning my car using uprev.

 

So it was running fine before the install of these parts? The o2 sensors can adjust fuel by 25% ea. You could have an intake leak. Coils connected wrong. Timing not set correctly. Fuel basket mods could be done wrong. I don't think the problem is the tune... something went wrong with the install of those parts.