Hello everyone, hope you are all having a good Saturday!

So, this past week my car started having idling issues right after Hurricane Irma passed by Florida (great timing huh). The first time I turned on my car to go to work the car seemed fine, but in the afternoon while coming back home, the car's idle started increasing and decreasing from around 1,200 RPM to 2,000 RPM continuously.

A couple of days passed by since then and I noticed the following:

- The car idles higher than normal when cold but the RPM's stay constant.
- The idle begins to inc/dec between 1,200 and 2,000 RPM continuously when the car is warmed up.
- Turning the AC on seems to lessen the idle swing but it doesn't disappear.
- Got a P0507 after a couple of days.
- MPG decreased, obviously.

I have tried the following with no success:

- Pedal position relearn.
- Throttle body position relearn
- Idle re learn.
- ECU reset procedure.

I did all these procedures plenty of times and I believe I have done them right, but the problem has not been fixed yet. The idle continues to swing and the P0507 code came back again.

I'm about to take the car to the dealership next week, but before that, should I do any other obvious check to the car before probably dumping a lot of $$$?

Thank you in advance, have a good weekend.

 

Reset your throttle body. It seems like it's out of place.

Edit: just saw you already tried that. I'm not sure unless I had the car in my hands.

 

Yeah, I tried all the resets. I took the car to the dealership today, and they cleaned the throttle bodies, the injectors, and reset all the computer/idle/etc, but nothing worked. Now they want to replace both throttle bodies for an amazing price of $1,380 ....

 

Just got the car back from them, paid for the cleaning and resetting but I'm keeping the car for a few days until I make a decision on the repair. Any last minute things I look for to see if I can get it fixed?

 

Lmao these prices make me regret I never opened my own shop.

A throttle body replacement is a 20 min job tops. That' literally 1,000/hr.

Throttle bodies are $60 ea.

Hell I'd do it for $500 and happily cash that check. Do it your self. If you were in SoCal I'd literally do it for free. I just took my friends off his 03 Z last weekend.

 

$1400 for replace two TBs ... unreal!

OP - do you have any car-starting / cranking issues? I pop P0507 all the time with my setup usually when I have to crank repeatedly for hot-starts.

When I replaced my battery and relocated it from the trunk area to the passenger side footwell (shorter hot-wire), I've had significantly better starts (both hot & cold) and I dont see that code much anymore.

just a thought...

 

hahaha it seems to be a very lucrative business, you got that right.

The guy at the dealer was so "nice", he said that since they already removed the TB's to clean them, he would only charge me for the parts (1 TB = $689) and no the labor. Oh and he threw in a 10% discount...

Anyway, I have been thinking about doing this fix myself. I found some Hitachi ETB0005 TB's on amazon for $311 the pair, and from what I read, these TB's are exactly the same our cars use so, I think I'll give it a try.

I wish I was in SoCal though! You seem to know your way around Z's.

 

Yeah its unreal

To answer your question though, I never had or have any problems with the car starting. Fires right up normally.

I did have hot-start issues with my older 3000GT VR4 but that's hands down a very problematic car.

 

What kind of car are we talking about here?...

 

Well now that you mentioned that....

 

I relocated my battery to my trunk for balance reasons and it was ill-fated. I lost quite a bit of amperage running the ~15' of wiring back to the OEM starter/alternator fuse-block. Lesson learned.

I wish the kind folks over at Photobucket were so inconsiderate with their 3rd party hosting or I'd have more pictures posted. If you care, my progress is on my IG acct.

https://my350z.com/forum/forced-indu...n-build-7.html

 

Ahhh, got you. I'll check that link now, looks interesting!

 

Ahhh, ok. Gotcha'. Sounded like it was originally IN the trunk.

 

nah - oem location ... I put it in the trunk - like I said though, ill-fated and it needed to be closer to the OEM fuse box. nothing ventured nothing gained.

 

Right.. Lessen learned though.. Maybe one with a higher shield rating to reduce amperage degradation would've worked for ya'?

 

I dont know (but could probably figure out) the exact science behind the energy loss but I knew I was going to a braille battery at some point in time so I didnt freak out about it too much. A good lesson to say the least and maybe why OEM's are rear-mounting batteries more often.

 

I gotcha'. Makes sense.. And I thought they started rear-mounting batteries because it had something to do with safer frontal impact standards, but I'm not sure. Eh, whatev.

 

Any signs that the park neutral safety switch has lost connection?

After 6 speed swapping a car I threw P0507 until I hooked that wire up. This was with an auto ECU so it kicked the idle up when "in gear".

 

No chance of that, my car is MT.

 

So after some research and looking at my options, I think I will give it a shot and order the Hitachi ETB0005 Throttle Bodies from Amazon for $311 (both) and replace them myself. Hopefully this helps, and if it doesn't, I think my best bet would be to replace the ECU (I read in some threads that it could fry also). Wish me luck!