claytontnelson

I recently purchased a 2003 350z that has been having power loss issues.
Car will lose power randomly through out the RPM range.
No engine lights. Idles and revs just fine.
Mods are
Cat back exhaust and a injen short ram intake

I made a video to help explain.

Any help or insight will be much appreciated.

myfirstzcar

How long has this been happening? Do you oil your air filter? Did you over-oil the filter?
I think you should get some MAF cleaner and start by cleaning the MAF.

travlee

iTrader: (8)

have you ever changed the spark plugs? did it happen before the mods or just after..

i didnt watch the whole video because i am at work but it would be nice if you put a time of the video that it happens

claytontnelson

maf has been swapped with another one and plugs are brand new.

Purchased the bar with those mods

travlee

iTrader: (8)

and has it always done it?

claytontnelson

since I've had it which is a week now.

Neimad

Isn't the Service Engine Light on?

iStan

iTrader: (29)

Looks like it but OP said no engine light?

myfirstzcar

No cel, but that doesn't mean there aren't any codes. Use a scan tool and look for codes, mine had power loss up to about 4000 rpm when the knock sensor went bad....There was no cel.

Neimad

I bet $20 OP thinks Service Engine Soon means it needs an oil change.

claytontnelson

Im not an idiot.... as a matter of fact i bought the car with a blown engine and swapped it with one i had in one of my 240sx's. But thanks for your negative comments cluttering up my thread. check engine light is not on. car runs good or bad from one minute to the next, and when i say runs bad i mean losses power around 3500-4000 rpms randomly. Everything else works fine. Idles smooth and drives fine at lower rpms. One issue i have noticed is the cruise control set light will flash when its having the power loss issue.
Im waiting for my UPRev to be returned to me so i can data log the computer.
Maybe that will give me a better idea to whats going on.

Thanks to everyone else who's making suggestions. I appreciate all the input.

Neimad

Whats the bright yellow light on the lower left of the instrument panel thats on while you are driving?

claytontnelson

TPMS (tire pressure monitor sensor) light, car has aftermarket wheels.
Car has no codes when scanned.

Im not some yokel with a 350z.
I'm just unsure of whats causing this issue. Car literally runs different from one run time to the next. I can drive the somewhere and it will make good power and feel great, park it and come back five mins later and it'll have no ***** above 3500 rpms.

But like i said cruise control will function correctly when the car is running properly, and when its not running well the cruise control set light will flash when i attempt to engage the cruise control.

I'm waiting for my Uprev tuner to be returned along with my spare ecu's. To further test the car.

Neimad

Sorry, but with the level of intelligence of most posts here and 50% of customers with that light on misunderstand, so I had to make sure, but really sorry dude.

So, no codes power, one minute, recent engine install...I would check grounds really well. Can you read the full OEM and OBDII datastream with the uprev? I'd like to see the throttle request and actual values, fuel commands, etc at the power loss moments. It could be loss of cam/crank signals, vss or something with the ECM deciding to cut fuel.

Neimad

And check IAT, maybe that short ram is getting heat soaked

travlee

iTrader: (8)

i am going to say he has an air leak somewhere.

Edit..... forgot to say on the intake

claytontnelson

Heat soak wouldnt cause this type of power loss, its full power to nothing.
If i had to guess i would say ecu issue or throttle body issue.

travlee

iTrader: (8)

do the ecu reset, throttle relearn, idle air relearn....

claytontnelson

I've done it already.

myfirstzcar

I don't know much about tuning, but I will say this....are your maps changing while you drive? You did say the cruise light would come on.