2010 EX35 - Idling & Starting Issues

[vancity16]

Hello Everyone,

Pretty much every time I come to a stop, my engine will momentarily idle down from ~1000 RPM to 400 RPM (where the car shutters a bit) and then back to 600 RPM where it sounds ok.

More recently, once every few weeks, I'll start the car it will idle up and then just die. It does this until I Rev the engine, and then it won't have issues starting for a few weeks.

Any ideas?

Thanks!

[CustomLowz]

How many miles are on your vehicle? I'm wondering if you would benefit from a fuel system cleaning. You might have carbon buildup in the throttle bodies which would cause the car to stall upon startup. I had that issue with my 2011 until i had both throttle bodies replaced and the issue went away. ( I was going to get them cleaned before but since they were replaced - no need.)

[vancity16]

Cheers, thanks for the quick reply!

It's got 45,000 miles on it.

How much did the throttle body replacement run ya/

[CustomLowz]

Cheers, thanks for the quick reply!

It's got 45,000 miles on it.

How much did the throttle body replacement run ya/

I had them replaced under warranty due to a CEL for the mass airflow sensors throwing codes. That happened around 60K for me.

[schaffs04]

Welcome to the infiniti VQ engine. The only real downfall of this setup appears to be the ability of the throttle bodies to get very dirty very quickly. I've had 3 of them, all with a similar issue. Likely the throttle bodies need to be cleaned. Worked on my I30 and my G35, and needs to be done on my 08 EX35.

Hope this helps!

[vancity16]

Did you clean the throttle bodies yourself? I read that it is very easy to damage if you even lightly touch the butterfly valve.

[schaffs04]

I did my own, as many have. It depends on your level of both skill and confidence. The key is to not move the butterfly valves manually at all, and not to disconnect the electronic connection to the throttle body. Took me about an hour or so and while it's not perfect, it no longer stalls. Be sure you use ONLY Throttle Body cleaner specifically and not some other cleaner.

Google cleaning G35 throttle body and you'll get a ton of results including some videos. The set up on the G35 under the hod is identical to our EX35, but since a lot more people drive the G, and they're popular with racers and gearheads, there are a lot more resources.

15 years ago the dealer hit me with $350 to clean them. If you have to ask how much replacement throttle bodies are, as the saying goes, you can't afford it. Crazy expensive.

[Lapin]

I had them replaced under warranty due to a CEL for the mass airflow sensors throwing codes. That happened around 60K for me.
[/quote]

Would have loved this thread back in March when I had similar issues. 2012 EX35 with 115K KM pulled the MAF code. I cleaned, switched the MAFs around and finally broke down and bought two new sensors in September. I attributed the problem to the Aftermarket K&N air filters. I have the same "lazy" idling and she seems to be more sensitive to the cold weather. Now I think it's time to clean those throttle bodies and see if the code is permanently fixed. Curious to know why the MAF code is thrown when the throttle bodies are dirty...

[piSSko]

why not to move the butterfly valves manually and not to disconnect the electronic connection? when I clean mine I didn't move them and couldn't clean then properly so I just left as it is. Btw, I found some tutorial to disconnect the car battery so car's computer wouldn't have power at all and I guess, wouldn't remember the butterfly valves positions.

[schaffs04]

Enough horror stories of people damaging the throttle bodies by moving them or disconnecting them. I've heard you can fry a portion of the ECU if you're not careful. Surging idles that can't be tamed are not unusual. Better safe than out 1,500-2k.

[gkdyeung]

serendipitously ran into this post...
i have the same starting problem.
despite an idle reset and a fuel system cleaning.
i have put a few more kilometers on my ex. approaching 220k.
still runs like new otherwise.
maybe it's time for clean throttle bodies then.
it's too bad "trial and error" is needed to come to a diagnosis at infiniti.
though... that may be intentional...