hey so i have a 03 350z and i currently just bought it and it’s in limp mode and won’t get any power to the throttle body won’t rev past 1.5k and i’ve checked the throttle positioning sensor that’s good i got a oem throttle body brand new and it still won’t rev thought it was the maf so i got a new one still won’t go past 1.5k i think it could be electrical but not sure i also don’t have the fuse cap from my fuse box behind the battery so if anyone knows what’s going on please lmk

 

Edit: Smooth brain move, the codes are listed in post Title/Header.

Ok, so you replaced the TB with a new OEM unit, good. Did you go through the Throttle Position or Idle Air Relearn procedures? You mentioned the vehicle won't rev past 1.5k RPM, so it sounds like it's at least starting up. Try the Idle Relearn procedure 1st, if that yields no results, then you most likely have a wiring fault. Check your harness wiring at the TB, look for corrosion or damaged shielding. Also check the fuse box for corrosion since you mentioned the cover is missing. Also check all your fuses and relays. Lastly it could be a loose connection at the ECM (in passenger footwell). Inspect the harness there for corrosion or poor contact. Should be common sense, but make sure to roll your windows down & disconnect your battery before playing with the wiring.

If that fails to yield results, then more in depth troubleshooting will be required with a wiring/circuit diagram and volt meter to check continuity.
Good Luck!
-Icer

 

i looked at the fuse box that is tucked behind the battery and the relays look like they are melted around the relays could this possibly be the reason

 

also when i got the car it was sitting for a year before hand and i replaced the maf because it got super hot so i don’t know what was going on with that

 

prev owner did a weld on the battery tie down but and it got way to hot and just eroded over time thanks for the help

 

Based on what you're describing, it sounds like there was a serious electrical short. The IPDM (engine bay fuse box) probably needs to be replaced. There's a strong possibility that other wiring was damaged. If the wiring looks crispy/burnt/discolored around the IPDM, then I wouldn't even try to re-use it. I would gut and replace. Whenever major electrical shorts are in evidence, there's a strong possibility that computer modules could also have been damaged. It's difficult to know without trial and error. The concern here is what caused things to get so hot to begin with. That's highly unusual unless someone, who had no clue what they were doing, was in there messing with the factory wiring (think aftermarket stereo or other addons). Alternatively, something like a small engine fire, but engine fire damage would be super obvious so I'm leaning towards an electrical fault.

Also....the battery tie down was welded? How so? The hold down bar is known to corrode from leaking battery maintenance caps, but these are cheap and easy to replace. I hope the prev-owner didn't weld the J hooks to the battery tray.

If you don't have the skillset to troubleshoot further or re-wire the vehicle, you might want to ask yourself if it's worth spending more money & time on it. I don't know what you paid for the vehicle, but this could easily turn into a money pit. Think about cutting your losses now vs. later. Consider getting a professional's opinion on the car before throwing more parts at it. This is not something that folks online can virtual assist with further, this needs hands on diagnosis.

Good Luck!
-Icer

 

the he tried to weld the tie down and he didn’t take out the fuze box and half of the box was melted couldn’t even take out a relay im thinking that’s it because it’s really eroded too so 100% is that because stereo works in the car i think he welded to close i have a picture of the fuze box looks toast

 

Wow, that was one hell of a smooth brain welder. That's the obvious place to start, replace the whole fuse box, I would also get rid of w/e pieces he welded and replace. Please post pics so we can all look in awe at this ****-up.

You should be able to source replacements from a Junk Yard or dismantler for cheap. These are not parts in high demand.
Cheers!
-Icer

 

Speaking of high demand, may want to try contacting SAC auto parts in Sacramento CA. Ask for Eduardo, he's saved me $ and agood guy.

 

hey i still haven’t gotten this thing to rev past 1.5k im thinking it could be a short or disconnected wire just wondering if it could be the ecu i talked to recent owner and he said he parked it running and now we are here so im just lost on how something ran before winter and now won’t rev so im just thinking on what it could be the code says power to throttle body and im not sure how it got hot would a good ground and bad power would make the maf heat up just don’t know if anyone of y’all could dm your phone number that knows a few lmk

 

i’ve been looking at the wiring nothinh looks fired just seems like isn’t getting power to ecu

 

got a new fuze box because it needed it just want to know if it could be a fired ecu how could you tell. could i do a ecu reset would that help

 

Do you have a factory service manual?
If not it would be a good idea to have on hand for wiring diagrams. Seems like you are going to need it.

 

i don’t have it dude drifted it before me and he said he didn’t have it

 

I think there's a thread in the maintance section, search? Also if you have a dvd drive on your computer, Rock Auto has them available by year. Cost for me about 9mo ago was $ 20.
Hope this helps you out. Good luck.

 

so we did a ecu reset and the throttle body opened for the start up and then didn’t receive any more power after that went back into limp mode so anyone have a good idea on what i could be pls lmk sounds like wiring to me but if it’s something that i’m not catching then could save me a bunch of time going through wiring harness today

 

Could be a ground fault. Check all the major engine bay ground wires. But at this point I would need to be hands/eyes on to give any further advice. Best to go through the wiring and look for open or shorted circuits.

Also, you should be able to download a copy or chapters/sections of the FSM in pdf from Nicco club still.
Cheers!
-Icer