Gas Smell while accelarating hard ....

[greenwar]

Today I took out my J30 for a weekend cruise and showed off the power of this machine to some unsuspecting 300C and Dodge charger drivers.

However, I noticed(rather smelled) something strange. Under hard accelation, I smell gas. The smell goes away almost instantly. Engine seems to idle just fine but after a little bit of driving, it seems to give out gentle shaking. Like if I am stopped at a stop light, I feel the car gently shaking. When I put the transmission to neural, the shake was more noticable. Are all of these indication of bad/dying fuel injectors? I put in some injector cleaner today with a new tank of gas.

Any suggesstions - comments?

Bugaboo, EricCire - what happend to you guys? I was really hoping to hear the name of a reliable mechanic in the Twin Cities area...

My worst nightmares may be coming true..

[driftkaztik]

make sure the injector seals are not leaking.... i know that Z31s 300zx, M30s and maximas used the same engine that had leaking injector seals and that the fuel could leak and catch the engine bay on fire.

if you smell gas, it probably is. have it checked.

[greenwar]

make sure the injector seals are not leaking.... i know that Z31s 300zx, M30s and maximas used the same engine that had leaking injector seals and that the fuel could leak and catch the engine bay on fire.

if you smell gas, it probably is. have it checked.

I know of the maxima fuel line recall they had.

What's the best way to inspect if my injector seal is leaking? Get somebody else to accelarate at standstill and stand next to the motor? Or is there a more efficient way?

[driftkaztik]

really, since its a safety issue, an expert.

the last thing you want is to put it off and let it cause issues down the road.

[greenwar]

Point taken. Will take it to a mechanic tomorrow or tuesday for sure.

[NismoChi]

i know that Z31s 300zx, M30s and maximas used the same engine

None of the Z31s 300zx, M30 or the maxima use the same engine as we are, we use the VG30DE, and they use the VG30E, not even the block is the same, the head, the fuel rail and the injectors are totally different, one is side feed, and one is top feed. Only the VG30E series engine had the fuel leaking problem that needed for a recall, not ours. To my understanding, during hard accelation, smelling a little gas is normal. When you are in WOT, the engine is going to run richer than normal, when there is more fuel than the engine can burn, the extra fuel will just go through the exhaust and out of the car. And that is probably when you smell the gas, i'm not saying that your car doesn't have any fuel leak, i'm just tell you that you don't have to worry about it too much.

[driftkaztik]

I know the J30s have the Dohc motor.. what I was getting at was the symptons is the same as the recall.. so I dont know where you get that I'm implying we the Z31, f31 and JH30 Maxima have a dohc...

finish the sentance.

"i know that Z31s 300zx, M30s and maximas used the same engine that had leaking injector seals and that the fuel could leak and catch the engine bay on fire."

What I was implying is that these 3 cars used the same engine that had the same problem. NOT the same motor as the J30.

How people with leaky injectors know, is that the smell of gas is inside the car.

[yodawill2000]

If the upper ORing is bad I bet it would smell like fuel under the hood.Open it to WOT , pull over and see if theres wet fuel around the injectors?Just a thought.

[greenwar]

Hey hey, my respectful comrads out there. Don't start a fight....

Just joking. I will take a look at the motor right after it smells. The funny thing is, the car does not smell of any gas when I come home and try to smell something.

One thing I didnt understand. What do you guys mean by WOT ?

I will however get the injectors seal checked. I found a guy in Twin Cities who has rebuilt a 300ZX motor at one point. So hopefully he knows what he is doing. I took my accord yesterday and he seemed to have all the stuff to work on a car. Best of all, he owns a 300zx himself, the older one.... not the new shape.


Modified by greenwar at 8:33 AM 8/28/2006

[yodawill2000]

WOT = Wide Open Throttle Theres a microswitch that clicks when you floor the gas pedal.It then knows you wanna haul A$$ !! hehe

[NismoChi]

I know the J30s have the Dohc motor.. what I was getting at was the symptons is the same as the recall.. so I dont know where you get that I'm implying we the Z31, f31 and JH30 Maxima have a dohc...

finish the sentance.

Oh, i got you, my mistake.

[greenwar]

WOT = Wide Open Throttle Theres a microswitch that clicks when you floor the gas pedal.It then knows you wanna haul A$$ !! hehe

WOW = mean just wow.

I had no clue... Thanks again.

[yodawill2000]

I didnt know about the switch until recently

push the pedal to the floor with the motor shut off, you will hear the click.

[greenwar]

OK got the injectors inspected today. No sign of gas leak. I am guessing the smell is coming only during WOT. My mechanic (a nissan dude) mentioned his 2003 3.5L motor on maxima with 600miles on it smells of gas in WOT. so I guess I am ok in that aspect as well. Just wanted to post the update here.

[driftkaztik]

No fight or disrespect. Its just a misunderstanding and maybe I wasnt clear with my statements.

doesnt gas dry fast??? or at least evaporate?

[silkysmoothyjud]

If you suspect an injector leak, look for the tell tale sign, a brown run mark will eventually appear even if a slight leak is present (if your car doesn't burn to the ground first). If you can't see the leak upon first glance, (I'm cringing) unbolt and shift the plenum (in my case) and look a little closer, you'll see that brown run mark if a leaking injector is the problem. If you start smelling gas, stop driving it until you diagnose the problem: or if you want to live dangerously, carry a fire extinguisher.

[robmcole]

I had a smell of fuel about a year ago, and it ended up being a fuel line spraying fuel directly on my manifold. I'm surprised the motor didnt explode. $5 at Autozone fixed it!

[silkysmoothyjud]

Just updating, I had a gas smell in my cabin; I am in the process of changing my injectors in my q. If your car starts acting up after driving it for a while, it's an injector developing an "open" condition. Said injector will still ohm out correctly, but a vibration will occur after the engine has warmed up because the open injector will soak the cylinder with gas after a while. Good luck trying to find which one is doing it. I just got promoted and Niqole is getting all new injectors.....

[yodawill2000]

To add to Silkys post an Open condition or a leaking lower O ring can really ruin your day.

Not only is your Oil getting a good dose of Gasoline.It can cause what is called Hydrolock.A cylinder fuel of Fuel when you try to start the engine. It will bend the Valves with a quickess.

[silkysmoothyjud]

Thanks Yoda. In the most extreme cases I believe it could. Wouldn't blue smoke be coming from the tailpipe if an extreme amount of gas is dumped into the cylinder? I was told that the scenario in reference to an "open" condition in an injector occurs when the in injector is constantly shooting gas into the cylinder and the injector will not close because of debris or something keeping the injector from closing. The excess gas in the cylinder will cause a "wash" condition and degrade your oil because the excess gas in the cylinder will eventually bleed past the ring down into your oil. That is why the car starts out fine after sitting for a while (we'll say overnight) and then develops a "mis-fire like" vibration after running for a while. I am not an expert here, and I realize that bad gas (water in gas) can cause the same symptoms, but that is what I was told. Please someone chime in if I am missing something here. I believe a check engine light should come on if the condition was getting bad.

[yodawill2000]

I dont recall the blue smoke when I had a leaky injector but then again I wasnt looking for it.The symptom I had was if I shut the motor of for say 10 to 15 minutes and then tried to start it it would take about 20 seconds before all 6 were firing.But if it sat overnight it started up just fine.Thats when somebody here mentioned it might be leaking and it went out and smelled the end of the dipstick.Bout' had a heart attack.Super strong fuel smell.I suppose after shutdown the fuel pressure was causing the cylinder to fill but after the pressure was down all the fuel went passd the rings to the crankcase.I replaced the oil every 2 days till I replaced the injector.

[silkysmoothyjud]

How did you find out which injector was doing it? My only solution is trial and error, a very tedious process indeed. Ive modified my intake for easy removal by using little c-clamps to hold it down, it sucks. I just replaced the last cream color injector. Now all of mine are purple, I've replaced 1,3, and 4 with no more clues, its gonna be a rough summer if I don't find an easier way to get my idle smooth. I am gonna mess with 2 next, since your supposed to do injectors in pairs and 1 and 2 get the bad gas first. I already loosened the screws with my little vise grips (the best tool for the q). My idle gets real rough in park (not after sitting overnight), and it idles at 500 rpm (I think the Q is supposed to idle at 750). Is there an idle screw one the Q45? Thats the only time the idle is rough enough to bug me, when the car is in park idling at 500 steadly....BTW my injector changes have made my transmission shift silky smooth. The first to second shift is hardly noticeable even when I gun it...

[yodawill2000]

I used an old school technique

Let it run for a few minutes . shut it down and started pulling sparkplugs one at a time.Had a QTip taped to a piece of clothes hanger wire.Dipped the qtip down into the clylinder and touched bottom.Pulled it up and when I got to the bad cylinder the qtip was damp with fuel.

[silkysmoothyjud]

wow that sounds scary, but not half as scary as removing the plenum four more times. If you think I have a leaky injector, its worth a try. What kind of tape did you use? Did the leaky injector foul out its plug? Did you do it while the motor was hot? What if that q-tip gets stuck down in there? I am going to try it this weekend and report back once I get some answers. Thanks for the feedback, your gonna save me about three weekends of pure plenum hell...