Newb, hot start problems and introduction

[expo5.0]

Hi-

We just picked up a G35x for my girlfriend. Got a great deal on a 2004 with 41k miles. However, the car has one slight issue- when it is warm it won't start unless you give it a bit of gas upon start-up. The car turns over revs to 2k or so and then shuts back off again. Even the slightest pressure on the gas pedal will avoid this issue. Car starts every time when cold and car turns over/starts to start every time when warm. Any ideas?

Thus far since we picked up the car i've changed the oil with royal purple, tinted it and swapped to a k&n filter. Also cleaned the maf and a few other parts. Plan is to leave this car stock for quite a while. When she wears these tires out will likely upgrade wheels and tires and we are on the fence so far as adding the stock rear wing. Also, i'm sure i'll end up throwing some audio equipment in it at some point (i own an installation company and do a lot of work part time).

here's a picture thus far-



I currently drive a 1999 C43 Mercedes with a very nice audio/visual system (image dynamics idx24/idq31 processing, cd1 pro horns, cx62 mids, boston pro tweets, stereo integrity substage etc. etc.) some suspension work, some styling stuff (but keeping it stock looking if possible) and an eaton supercharger. Some of it is currently "in-progress" but will be put back toghether in the next couple week for worldstreetchallenge.com show where i'm running/judging audio portion.



I also have a bagged 1996 explorer with many many body modifications and a couple of stock vehicles i just use for transportation (1998 suburban and cutlass).

the G35x is in some ways a replacement for my Bugeye that was totalled at the end of January. It was making 278 hp 254 ft lbs on a dyno dynamics when it hit the truck, lol.

[G_whizz]

Welcome to NICO!

Glad to have you onboard!

I really haven't got a clue and I don't want to mis-diagnose... hang tight and the boys will chime in here VERY shortly!

[Eikon]

I'm not so familiar with the VQ engines, but I'll take a guess at what the issue might be just based on general knowledge.

I would guess you have a plugged or clogged or broken idle air controller or auxiliary air controller.

I think it has less to do with gas into the engine and more to do with air into the engine. When you hit the gas pedal, what you are doing is opening the throttle body a bit, which allows more air into the engine. The ECU then compensates for more air by adding gas... hence we call it a gas pedal.

Here's what I would try... 1.) Clean the throttle body with carb cleaner and make sure it's operating smoothly and properly. 2.) check an FSM for the location of either idle air controller or auxiliary air controllers.. They will be around the intake manifold somewhere. When you track them down, remove and clean them to make sure they are operating proplerly.

On a warm day, does the car studder on startup after you've been driving? Or every single time? If you start it and drive to work, then turn it off in the parking lot, then immediately start it back up, does it have trouble again?

[Beancooker]

Try this also...

zerothread/299577

[expo5.0]

I'm not so familiar with the VQ engines, but I'll take a guess at what the issue might be just based on general knowledge.

I would guess you have a plugged or clogged or broken idle air controller or auxiliary air controller.

I think it has less to do with gas into the engine and more to do with air into the engine. When you hit the gas pedal, what you are doing is opening the throttle body a bit, which allows more air into the engine. The ECU then compensates for more air by adding gas... hence we call it a gas pedal.

Here's what I would try... 1.) Clean the throttle body with carb cleaner and make sure it's operating smoothly and properly. 2.) check an FSM for the location of either idle air controller or auxiliary air controllers.. They will be around the intake manifold somewhere. When you track them down, remove and clean them to make sure they are operating proplerly.

On a warm day, does the car studder on startup after you've been driving? Or every single time? If you start it and drive to work, then turn it off in the parking lot, then immediately start it back up, does it have trouble again?

any time the temperature gauge reads anyting other than basically "minimum" it doesn't start- including immediately after shut-off.

I too agree it seems to be an air problem and not a fuel problem- I did think cleaning the tb/mas and replacing the super gummy stock air filter would likely solve the problem initally. That is why i did those things right away/prior to posting.

it is probably one of those other "controllers"- wouldn't a malfunctioning idle air controller effect the idle once it's running as well? i'm not clear on the function of the aux air controller.

-drew

[Sentientbydesign]

I'm not so familiar with the VQ engines, but I'll take a guess at what the issue might be just based on general knowledge.

I would guess you have a plugged or clogged or broken idle air controller or auxiliary air controller.

I think it has less to do with gas into the engine and more to do with air into the engine. When you hit the gas pedal, what you are doing is opening the throttle body a bit, which allows more air into the engine. The ECU then compensates for more air by adding gas... hence we call it a gas pedal.

Here's what I would try... 1.) Clean the throttle body with carb cleaner and make sure it's operating smoothly and properly. 2.) check an FSM for the location of either idle air controller or auxiliary air controllers.. They will be around the intake manifold somewhere. When you track them down, remove and clean them to make sure they are operating proplerly.

On a warm day, does the car studder on startup after you've been driving? Or every single time? If you start it and drive to work, then turn it off in the parking lot, then immediately start it back up, does it have trouble again?

It's true that what Eikon mentioned could be the problem, BUT we have electronic throttles, so there's a proper procedure for cleaning the butterfly valve without killing the throttle motor.

[expo5.0]

Try this also...

zerothread/299577

does this need to be done after every time the battery is disconnected?

[Eikon]

It's true that what Eikon mentioned could be the problem, BUT we have electronic throttles, so there's a proper procedure for cleaning the butterfly valve without killing the throttle motor.

Thank you! That's showing my inexperience with these motors. The "drive by wire" style throttles should be carefullly dealt with. Those could be expensive to replace if they were messed up.

[Sentientbydesign]

Thank you! That's showing my inexperience with these motors. The "drive by wire" style throttles should be carefullly dealt with. Those could be expensive to replace if they were messed up.

No worries. I liked the cable driven throttles better. There were no worries about breaking throttle motors and plenty of fun playing with the ECU.

[BrandAidDesignG35]

I used to have to give my altima gas to start, strangly, not when it was hot, only when you try to cold start

[joe603]

It actually sounds like you need a new TB...if the adjustment doesn't work, try taking it to the dealer and get them to fix...if you just bought it, they may work with you.

[telcoman]

Can we all assume you have a new clean Air Filter?

[expo5.0]

yes- new air filter

[elwesso]

I almost wonder if you have something like a clogged fuel filter or something along those lines.. Ive seen it on Q before, maybe because it dumps fuel during startup when cold, but not so much warm.

It still kinda sounds MAF-ish to me, just because you cleaned it doesnt mean its not on its last legs. The G35 engine bay is a furnace, even in the frozen tundra of MN!!

[Beancooker]

Try this also...

zerothread/299577

does this need to be done after every time the battery is disconnected?

Nope.

[TeflonG35]

It actually sounds like you need a new TB...if the adjustment doesn't work, try taking it to the dealer and get them to fix...if you just bought it, they may work with you.

Yeah most places if they are reputable give you about 30 days after purchase. If it's that new i would say it's their problem and save your money. When i bought my G it has bald tires and beat breaks and wouldent pass inspection. The dealership swapped my breaks and gave me brand new mitchilen tires rated for like 145 mph.

They also changed my stock radio and fixed some trim on the side of my car for free.

[Sentientbydesign]

Yeah most places if they are reputable give you about 30 days after purchase. If it's that new i would say it's their problem and save your money. When i bought my G it has bald tires and beat breaks and wouldent pass inspection. The dealership swapped my breaks and gave me brand new mitchilen tires rated for like 145 mph.

They also changed my stock radio and fixed some trim on the side of my car for free.

You bought it from Infiniti?

[Focusedintntions]

If the car only has 41k...doesn't that mean it's under warranty?? I'd just take it to the dealer and have them diagnose....

But my guess would be to check the fuel filter. They should be replace about every 20k or so. I noticed my old car would struggle to start when warm or cold till i changed this out.

[TeflonG35]

No. A honda dealership lol. I was just looking in used lots.

[Sentientbydesign]

Two things. 1st, your car is still under infiniti warranty, so go let one of their service departments fix it.

2nd, we don't have replaceable fuel filters IIRC. Since about 2000, Nissan/Infiniti only has the screen filter located in the fuel pump.

[expo5.0]

thanks all

[MaximumRPM]

Hello Gentlemen I'm the Dad of a Son who owns a 2008 Infiniti G37. We are having a problem locating the "Fuel Filter" Could anyone out there direct me where to look ?

[telcoman]

Hello Gentlemen I'm the Dad of a Son who owns a 2008 Infiniti G37. We are having a problem locating the "Fuel Filter" Could anyone out there direct me where to look ?

Look here

http://www.nicoclub.com/FSM/G37/Coupe/2008/FL.pdf

See page 14

"CAUTION:
Never disassemble fuel filter and fuel pump assembly."

Telcoman