So I just finished up putting the motor back in my 03 350z. Car ran fine prior to pulling the motor. The upper oil pan cracked so that is the reason for replacing. Well I the car idles fine up until it warms all the way up and the fans kick on. Then it wants to stall. Sometimes it does stall other times it just idles up and down 100ish rpms. I did the throttle learning procedure. It is not throwing any codes. Anything else I can check? Thanks

 

How about when you turn on the rear defogger?

 

Sorry. I meant Efan on the radiator

 

Right. Does it also stall when you turn on the rear defogger?

 

I'll check tonight when I get home

 

I turned the rear defroster on at various times while the care was at idle and all it did was slightly mess with the Rpm's. That's with no fan running.

With the fan running it didn't stall

Also I just have the intake tube with the maf bolted on. Will that cause issues it the air box itself isn't attached?

Also oddly enough it didn't stall when the fan kicked on today.

 

As long as the maf is in the tube and connected it should run fine. Your car's ECU may have simply needed to find it's happy place again.

 

Yea I sure hope so. It was a pita pullin the motor twice.

 

Check all wire connections/ ground connections.. Your ecu might have to re-learn itself, meaning drive your car.. For a while

 

Thanks. I'm hoping to have it drivable tomorrow. Just have to put a few more parts back on and take it off jack stands. Can't wait to finally be driving it again

 

Did you ever figure out your problem? Mine does this same thing, replaced the fan motors, new oem maf, new alternator, cleaned the throttle body, new plugs, new ac compressor(thinking the clutch might've started to seize and slowed the belt down when the fans and ac are on), and checked multiple times with different code readers with no luck. Any help would be deeply appreciated. Btw, I have an 05 base package with a VQ35DE and manual trans.

 

I have the same problem! When the fan kicks in it makes the idle really rough and sometimes the engine turns off. Any idea on what the problem might be?

 

I've been dealing with it still, and I've kinda came to the conclusion that it's either a grounding issue or I need a tune. I've replaced the fan motors, alternator, oem maf, spark plugs, battery, ac compressor, belts, cleaned the throttle body, replaced the pcv valve and hose, cleaned all grounding points, checked compression, seafoamed, replaced air filter, o2 sensors, and I could probably keep listing more. But I've kinda came to the ground wiring, or I need a tune. Sorry wish I could be of more help.

 

Guys, it's so much cheaper to take the car to a dealership to have it checked on the CONSULT II computer than it is to just throw parts at the problem.

 

Did anyone ever figure out the solution to this problem. My z has started doing this as well. Thanks

 

take Zak's advice.... from close to two years ago