# Z31 VG30E engine trouble, bogs and runs rich



## BoBakTXL (Aug 30, 2004)

Hey guys, first off all, I made a video, to show whats wrong:

http://home.comcast.net/~bobaktxl/05-04-06_0853.3g2

Thats Quicktime format (from my cell phone)

Anyways, whenever i go wot or engine is either under or not under load, it feels like its running SUPER rich, it cuts out on me, and lets say im at a stop light and go WOT in nuetral, the motor takes a few seconds to get to 6k, in between idle and 6k it runs like it has a little bit of water in the cylinders (an example), its really weird, it feels like as if its dumping WAY to much fuel in to the motor and the plugs cant fire the incoming fuel or something?

Anyways if you keep it WOT in nuetral or driving long enough, the motor will "clear out" and will run perfect if kept at WOT. Another thing, if im cruising, lets say in 4th at 40mph (2000 rpms), and i downshift to 2nd (now at 4000 rpms), and go WOT it takes like 1 second of bogging down (sounds like to much fuel?) and then the motor will "clear out" and run perfect, wtf is going on?
thanks alot, 1SIKZ31

1986 Nissan 300zx NON TURBO 5 speed VG30E.


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## Spongerider (Nov 18, 2002)

Check your spark plugs.


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## BoBakTXL (Aug 30, 2004)

http://home.comcast.net/~bobaktxl/05-04-06_1011.3g2


Put your volume up and listen to the studder at around 3krpms, from the video it sounds like a small studder, but when driving its like slamming in to an instant brick wall and then WOT again, its like a power onnnn... power off.... power onnnn type of thing, like the engine was turned off and then turned back on..
What in god could it be?

thanks !


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## BoBakTXL (Aug 30, 2004)

any other replys?


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## BoBakTXL (Aug 30, 2004)

anything else other than "check ur spark plugs?"

please!


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## Spongerider (Nov 18, 2002)

BoBakTXL said:


> anything else other than "check ur spark plugs?"
> 
> please!


Well, did you check your spark plugs?


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## asleepz (Feb 24, 2004)

Spongerider said:


> Well, did you check your spark plugs?


Of course not....


Change your spark plugs, disconnect your battery before you start and reconnect it after your done.


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## BoBakTXL (Aug 30, 2004)

I bought 6 NGK V-power resistor type spark plugs, im i guess going to keep the gap the same?

Ill post results afterwards.

By the way, I bought and installed a new bosch 02 sensor like previously stated, and now my idle is ROCK SOLID and the "bogging" decreased by like 20% but it still bogs up to the point now that if im in 2nd gear lets say at 3k rpms driving, and I go 30mph (cruising), and I go WOT (wide open) the engine is creating ZERO whp, its actually DE-celerating, the rpms go down and its giving off the "im getting ZERO fuel and only air" sound, another way to do this is to be driving and take ur key out (engine off but still spinning) and try to throttle it with it off but spinning (vehicle is moving) its just the "air sucking in to the motor and in to the cylinders" sound, its the EXACT same thing.

Plus.
I had the hood open and had 1 hand on the MAF, and one hand on I think the TB, and I revved the motor up, and got ZAPPED, freaking electricity (HIGH voltage) went through my body, i couldnt feel my arms for over 5 mins, the higher the engine rpms went the more the MAF zapped me, wtf is that all about?
I was the ground to the MAF?

So I was told to re-ground my MAF since its "floating in the air" (custom intake) and I did but still bogs like no other, not really a bog, but more like TONS of fuel.


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## BoBakTXL (Aug 30, 2004)

problem SOLVED!!!!!!!!!!
spark plugs, all 6 had were burnt white (lean?)

thanks alot guys!


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## Spongerider (Nov 18, 2002)

BoBakTXL said:


> problem SOLVED!!!!!!!!!!
> spark plugs, all 6 had were burnt white (lean?)
> 
> thanks alot guys!


Gezzz....... Thank you, thank you very much! (Elvis voice)

What took you so long?


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## asleepz (Feb 24, 2004)

Yep white is lean... Did you unhook the battery like I said so it would reset the computer.


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## Spongerider (Nov 18, 2002)

If your plugs were that woren down I would suggest replacing your _fuel filter _and _fuel dampner_, and _fuel regulator_.

This should take care of your lean problem.


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## BoBakTXL (Aug 30, 2004)

Spongerider said:


> If your plugs were that woren down I would suggest replacing your _fuel filter _and _fuel dampner_, and _fuel regulator_.
> 
> This should take care of your lean problem.


Whats a fuel dampner and where is it located?
Never heard of it before?

Also, sometimes in the mornings i turn on my car with my fuel pump cut off switch "off" so the engine runs on the fuel in the lines then leans out and dies, I did this over a years time a few times a week, could that cause over time for the plugs to turn white and all like that?

thanks.


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## Spongerider (Nov 18, 2002)

BoBakTXL said:


> Whats a fuel dampner and where is it located?
> Never heard of it before?
> 
> Also, sometimes in the mornings i turn on my car with my fuel pump cut off switch "off" so the engine runs on the fuel in the lines then leans out and dies, I did this over a years time a few times a week, could that cause over time for the plugs to turn white and all like that?
> ...


The FPR and the FD are located after the fuel filter just trace the fule lines. As for your other question it could.


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## BoBakTXL (Aug 30, 2004)

hmmm....

Fuel damper is around the fuel rails?
or?
thanks

By the way: I dont know why but it feels like I gained over 10whp and torque from plugs and 02 sensor and plug wires?


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## Spongerider (Nov 18, 2002)

BoBakTXL said:


> hmmm....
> 
> Fuel damper is around the fuel rails?
> or?
> ...


It should before and after the fuel rail.

Remember that spark is 1 part that is needed for combustion. The bigger the spark the better. 

Im sure you did gain hps.


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## nismo897seZ (May 19, 2006)

the next time it feels like its messing up or "bogging" as its called, when it sounds like you have water in your cylinders, you might wanna take a look at your MAF sensor and/ or your FPR those play a pretty big part in you running rich.


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## BoBakTXL (Aug 30, 2004)

Update:

The car is running awesome, pulls HARD, but recently 2 days ago, the car has been showing an EXTREMELY small sign of "turning off".
The engine doesnt bog anymore, doesnt sound like water in the cylinders, it ONLY happens under heavy loads (10mph 2nd gear giving decent throttle), or 1st gear around 5mph or so, and I will have the pedal pressed to move the car slowly, and the engines power GOES DOWN like to 70whp (just guessing) and then goes back up to normal.
Its like the engine is "off" but is still "pushing" the car, like a SUDDEN loss of power that comes back and doesnt occur ANYWHERE other than LOW speeds of 1st and 2nd gear (heavy engine loads)
What could that possibly be?
Thanks!


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## Spongerider (Nov 18, 2002)

BoBakTXL said:


> Update:
> 
> The car is running awesome, pulls HARD, but recently 2 days ago, the car has been showing an EXTREMELY small sign of "turning off".
> The engine doesnt bog anymore, doesnt sound like water in the cylinders, it ONLY happens under heavy loads (10mph 2nd gear giving decent throttle), or 1st gear around 5mph or so, and I will have the pedal pressed to move the car slowly, and the engines power GOES DOWN like to 70whp (just guessing) and then goes back up to normal.
> ...


Did you change the FP and FPR?


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## nismo897seZ (May 19, 2006)

BoBakTXL said:


> Update:
> 
> The car is running awesome, pulls HARD, but recently 2 days ago, the car has been showing an EXTREMELY small sign of "turning off".
> The engine doesnt bog anymore, doesnt sound like water in the cylinders, it ONLY happens under heavy loads (10mph 2nd gear giving decent throttle), or 1st gear around 5mph or so, and I will have the pedal pressed to move the car slowly, and the engines power GOES DOWN like to 70whp (just guessing) and then goes back up to normal.
> ...







check your TPS keep in mind that its a switch not a sensor in this case it would be a throttle position switch. get it checked out or if you have a DVOM get the specs. and try and match 'em up. get back to me with the results i've studied this field and not only was that the case on mine but also the MAF.


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