Cleaning throttle bodies

synolimit

Right. Gotcha. I'm interest to see what my AOS looks like in about 600 miles. Fingers crossed its low with my break in style. When I do my inlet tubes we'll see how clean the TB's look.

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13 370z-

DIGItonium

I personally haven't manually done the idle air volume procedure, but my techs have difficulty running the program via CONSULT.

The first attempt couldn't be done because coolant temps were too high. The second attempt couldn't be done because CONSULT would complain the ECU wasn't responding. The engine would idle up and down, values could be read, but for some reason it would output this error message.

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wstar

I've always done it manually since I don't have Consult, which is a crazy procedure involving very specific timing of presses on the gas pedal and whatnot (it's documented in a time-series chart in the manual). Usually I can get it right within 2-3 tries and it works. However, one time I had a hell of a time with it. Did it over and over and over and it would never "take", like I was screwing up the procedure. It turned out the problem was I still had an OBD-II unit plugged in under the dash (I almost always do for data monitoring/logging). As soon as I unplugged from the OBD-II port the procedure worked on the first try. I'm not sure what's up with that, but my assumption was that the ECU's thinking goes something like "If something's plugged into the OBD-II port and interfacing with us, they're probably using Consult so don't worry about listening for the manual procedures?" Or it could just be a bug, who knows.

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7AT Track Car!
Journal thread / Car setup details

DIGItonium

The techs didn't use the manual sequence. With CONSULT, you can call up the program (as well as other diagnostics) with a click of a button. Not sure why it's such a pain since I'm sure it had to be done at some point after getting the turbos installed.

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L33T Z34

When I change my NGK nickel sparkplugs out @ 30k miles, the TBs have to be removed, so that is when I clean them. As said previously in post 30, IF you dump your side valve cover crankcase breathers, not the PCV lines, to atmosphere (like me) or into a catch can the TBs won't become as contaminated w/carbon from blow-by. I would buy new PCVs (11810-EY00A) and PCV insulators (11812-6N200) at 90k miles on the OD.

KeVoH

Just to share my results, My Z was having a bad case of engine idle and some ping on low RPM's. I found a good deal on a M370 Manifold and decided to install it this last weekend. I bought MAF Cleaner for the intake sensors and when i swapped the M370 i cleaned the throttle bodies.. Man what a diference, my car is idling perfect. It feels more responsive.. can't wait to get a tune. Bottom line is that i reccomend everyone with 25k+ miles to clean the throttle bodies! I did the calibration process just in case.

JARblue

There is some excellent info in this thread. Thanks guys I think this will be my next maintenance project. It will give also me a chance to deep clean my intake filters with some Simple Green solution I'll be sure to post my experience as soon as its done. I am hoping it helps my idle, which seems a bit "off" lately.

btw, KeVoH, it is unlikely that cleaning the TBs will make your car more responsive. The intake manifold you installed is the reason it feels that way. You should feel it pretty good in the mid range and with a tune it should improve across the board.

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KeVoH

I agree! the responsiveness is thanks to the M370, but the idle issue went away! that's where TB cleaning came in handy cheers!

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Justice97

Reviving an old one.

Had a check engine light come on and idle issues. I took it to dealer and they told me that there was a bulletin about reprogramming the ecu, something about how my car was running rich, then lean then rich then lean and it was adding greater carbon build up on the TB. The reprogramming was covered under warranty, but the cleaning was going to cost $180.00. UMMM ILL DO THAT MYSLEF.

Anyway they told me that cleaning the throttle bodies should be done every 20k to 30K miles and should become part of my regular maintenance. Although it is not on the list of maintenance, it should be.

Will get my car back tonight and i will clean them myself tonight. They told me the check engine light will be cleared but because of the erratic idling it will pop back up till they are cleaned and working properly.

Will write back when I am done cleaning and take it for a spin.

kenchan

were you guys able to clean the tb without unplugging the harness?
im thinking that if you dont unplug it, no need to do any reset sequence...

JARblue

'They' say you can just spray the TB cleaner on them while installed. I don't know who 'they" is other than random voice on the internet. My first thought is I don't think I want that stuff in my intake manifold no matter how fast it evaporates. Second, after seeing it firsthand, you should really remove the TBs to get at the majority of the gunk on the back side of the butterfly valve.

I suppose you could possibly remove the TBs and lay a towel over the engine and try to clean the TBs over the towel while the harness is still attached. Seems like a hassle to me.

The reset is easy (car OFF 10 sec, ignition ON 2 sec, repeat once). Then mash down your throttle for the next 50-100 miles. Every time you accelerate give it WOT. As much as possible. Someone try this and see if you notice a change in how the car responds to your throttle input. It won't help with the lag on the stock tune, but I bet you notice a peppier response.

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kenchan

mr.jar- is that ignition ON as in start engine or just go to ON without starting the car? then turn off 10sec, and ON again 2sec and OFF.

i suppose if you keep mashing the gas, the ECU will be out of the eco mode so it will
behave more responsively than normal driving... until you drive normally again and
the ecu returns to mode?

JARblue

I was wondering the same thing myself. It is ignition ON while engine remains OFF. I actually did it incorrectly when we did the TB cleaning, but it still worked even with turning the car all the way on. The instructions say at least 2 sec on, so I let it come on long enough to settle and feel comfortable turning it off so quickly.

Also, I have a tune, so I'm not sure how much eco mode my car goes into these days But I did notice that the car seemed to give me more gas with less pedal than before. I also got more 'bucking' from the car while driving slowly in low gear at higher RPMs and letting off the throttle suddenly.

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kenchan

thanks for the info. that sequence is basically the same as accelerator pedal reset on the ealier models.

yah, since you have a tune perhaps you no longer have eco mode (i prefer not to have
eco mode too )

03g35coupe6mt

i have cleaned my throttle body on my G35 and my 370z and i removed them each time to get the inside clean i think as long as you dont push on the throttle plate and move it when its off you shouldnt have to do any reset . ive never had to . i think i unhooked the negative before i did it but not sure if even that is necessary if the car is off and i have re routed the coolant lines that were attached to them . the coolant still flows but no longer heats the throttle body.