Noob question! no pressure from gas cap? - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Medicom3 · 07-08-2011, 11:43 AM

Back pressure from the gas tank is back but the car bogs randomly now. HELP! Really appreciate it!

blingbling · 07-08-2011, 11:44 AM

Test the fuel pump

Edwin562 · 07-08-2011, 11:47 AM

leak somewhere.... check the gas neck if the rubber is ripped ....

Medicom3 · 07-08-2011, 02:35 PM

Quote:

Originally Posted by Edwin562

leak somewhere.... check the gas neck if the rubber is ripped ....

not rip at all

Medicom3 · 07-08-2011, 02:36 PM

Quote:

Originally Posted by blingbling

Test the fuel pump

How do i do that?

blingbling · 07-08-2011, 02:54 PM

Well get some help from a friend who is mechanically inclined, turn the key over and try to hear if the pump is priming. It should "whir" from the rear of the car for about 5 seconds (correct me guys if there is a better way to describe it lol) if you cannot hear anything test the fuel pressure(this is something you can search how to do). Is it bogging when you accelerate?

Medicom3 · 07-08-2011, 05:47 PM

Quote:

Originally Posted by blingbling

Well get some help from a friend who is mechanically inclined, turn the key over and try to hear if the pump is priming. It should "whir" from the rear of the car for about 5 seconds (correct me guys if there is a better way to describe it lol) if you cannot hear anything test the fuel pressure(this is something you can search how to do). Is it bogging when you accelerate?

Yea it bogs sometime when i fill it up half tank

KiLLeR2001 · 07-08-2011, 06:19 PM

When I open my fuel cap up I don't have any pressure released. I have my tank properly vented though. If you block off the vent you could damage the fuel pump from too much positive pressure.

mxexux · 07-08-2011, 07:12 PM

EVAP valve may be stuck open and the carbon canister is saturated. Or there is a leak in the EVAP circuit. This could cause the bogging by the engine sucking in extra fuel or a vacuum leak when the EVAP valve opens.

Tokona-x · 07-09-2011, 01:27 AM

Quote:

Originally Posted by mxexux

EVAP valve may be stuck open and the carbon canister is saturated. Or there is a leak in the EVAP circuit. This could cause the bogging by the engine sucking in extra fuel or a vacuum leak when the EVAP valve opens.

+1 for evap valve ive had the same problem in the past

Medicom3 · 07-09-2011, 09:25 AM

Quote:

Originally Posted by mxexux

EVAP valve may be stuck open and the carbon canister is saturated. Or there is a leak in the EVAP circuit. This could cause the bogging by the engine sucking in extra fuel or a vacuum leak when the EVAP valve opens.

Ok ill check that out. I also smell fuel when the car is running...

driftxninja · 07-11-2011, 10:39 AM

i have dealt with this exact problem for inspection 3 times.

is this for inspection or just your own fixing up?

anyways pressure not holding in gas tank

take off the fuel pump cover, there is a gasket shaped like an "O". it goes under the cover where the fuel lines go in and meets at the tank. you will see it. its worn or stretched out. trust me. its like 12 bucks for a new one. that fixed the problem all 3 times for me. (all different 240's)

driftxninja · 07-11-2011, 10:42 AM

also im not sure about the bogging. could be a connected problem if thats the case then prolly what those other guys were saying. could be a completely different issue though.

just my 2 cents.

have a good one.

Medicom3 · 07-13-2011, 07:59 AM

Quote:

Originally Posted by driftxninja

i have dealt with this exact problem for inspection 3 times.

is this for inspection or just your own fixing up?

anyways pressure not holding in gas tank

take off the fuel pump cover, there is a gasket shaped like an "O". it goes under the cover where the fuel lines go in and meets at the tank. you will see it. its worn or stretched out. trust me. its like 12 bucks for a new one. that fixed the problem all 3 times for me. (all different 240's)

thanks! just chabge it and the smell went away!

The car still bogs though when my foot is on the pedal.

driftxninja · 07-14-2011, 08:22 AM

no problem man! very common issue with these 240s.

as for the bogging that is a tough one... i would say that is most likely a fuel issue..

best thing is to do the cheap stuff first, like a new fuel filter like 10 bucks, check the fuel pump, make sure you have good fuel pressure, could try cleaning your injectors.

driftxninja · 07-14-2011, 08:25 AM

since you mentioned it bogs with like half a tank of gas

does it bog with a full tank or less than half a tank?

PM me for faster responses ok.

looking online it could be a number of reasons it bogs... found issues like o2 sensor, fuel filter clogged up, your TPS (throttle position sensor) could be bad.

Medicom3 · 07-16-2011, 11:02 PM

Quote:

Originally Posted by driftxninja

since you mentioned it bogs with like half a tank of gas

does it bog with a full tank or less than half a tank?

PM me for faster responses ok.

looking online it could be a number of reasons it bogs... found issues like o2 sensor, fuel filter clogged up, your TPS (throttle position sensor) could be bad.

Full tank and half tank of gas it still bog. I just change the fuel filter already.

pm'd!

driftxninja · 07-17-2011, 09:35 AM

does it bog all the time or randomly ? i think you told me random in your PM im too lazy to check again right now. ,haha.

so anyways does the motor shake when it bogs or anything weird happen? obviously the rpms drop

i had a problem once where my fuel injector would cut out on me randomly and my engine would run on 3 cylinders till it decided to work again

if it bogs down again i would try pulling over and looking at your engine bay, pull spark plug wires one at a time while engine is running, if you notice there is not any change in rpm after you pull one then that cylinder isnt firing. try that and let me know

is it like a quick just bog down and then boom your good or do you have continuos loss of power afterwards?

Medicom3 · 07-17-2011, 10:40 AM

Quote:

Originally Posted by driftxninja

does it bog all the time or randomly ? i think you told me random in your PM im too lazy to check again right now. ,haha.

so anyways does the motor shake when it bogs or anything weird happen? obviously the rpms drop

i had a problem once where my fuel injector would cut out on me randomly and my engine would run on 3 cylinders till it decided to work again

if it bogs down again i would try pulling over and looking at your engine bay, pull spark plug wires one at a time while engine is running, if you notice there is not any change in rpm after you pull one then that cylinder isnt firing. try that and let me know

is it like a quick just bog down and then boom your good or do you have continuos loss of power afterwards?

the rpm goes down for like 10 sec then it kicks back up again

07-08-2011, 11:43 AM	#1
Medicom3 Leaky Injector Join Date: Oct 2010 Location: Fremont Posts: 55 Trader Rating: (0) Feedback Score: 0 reviews	Noob question! no pressure from gas cap? Back pressure from the gas tank is back but the car bogs randomly now. HELP! Really appreciate it! Last edited by Medicom3; 07-16-2011 at 11:44 PM..

07-08-2011, 06:19 PM	#8
KiLLeR2001 Post Whore! Join Date: Jun 2007 Location: オーランドフロリダ Posts: 7,955 Trader Rating: (46) Feedback Score: 46 reviews	When I open my fuel cap up I don't have any pressure released. I have my tank properly vented though. If you block off the vent you could damage the fuel pump from too much positive pressure. __________________

07-08-2011, 11:44 AM	#2
blingbling Zilvia Junkie Join Date: Jan 2011 Location: phoenix az Posts: 360 Trader Rating: (0) Feedback Score: 0 reviews	Test the fuel pump

07-08-2011, 11:47 AM	#3
Edwin562 Post Whore! Join Date: Nov 2009 Location: Whittier (562) Age: 34 Posts: 4,721 Trader Rating: (35) Feedback Score: 35 reviews	leak somewhere.... check the gas neck if the rubber is ripped ....

07-08-2011, 02:54 PM	#6
blingbling Zilvia Junkie Join Date: Jan 2011 Location: phoenix az Posts: 360 Trader Rating: (0) Feedback Score: 0 reviews	Well get some help from a friend who is mechanically inclined, turn the key over and try to hear if the pump is priming. It should "whir" from the rear of the car for about 5 seconds (correct me guys if there is a better way to describe it lol) if you cannot hear anything test the fuel pressure(this is something you can search how to do). Is it bogging when you accelerate?

07-08-2011, 07:12 PM	#9
mxexux Zilvia Junkie Join Date: Jun 2008 Location: SoCal 949 Posts: 363 Trader Rating: (9) Feedback Score: 9 reviews	EVAP valve may be stuck open and the carbon canister is saturated. Or there is a leak in the EVAP circuit. This could cause the bogging by the engine sucking in extra fuel or a vacuum leak when the EVAP valve opens.

07-11-2011, 10:39 AM	#12
driftxninja Zilvia Member Join Date: Mar 2010 Location: Ventura Posts: 153 Trader Rating: (0) Feedback Score: 0 reviews	i have dealt with this exact problem for inspection 3 times. is this for inspection or just your own fixing up? anyways pressure not holding in gas tank take off the fuel pump cover, there is a gasket shaped like an "O". it goes under the cover where the fuel lines go in and meets at the tank. you will see it. its worn or stretched out. trust me. its like 12 bucks for a new one. that fixed the problem all 3 times for me. (all different 240's)

07-11-2011, 10:42 AM	#13
driftxninja Zilvia Member Join Date: Mar 2010 Location: Ventura Posts: 153 Trader Rating: (0) Feedback Score: 0 reviews	also im not sure about the bogging. could be a connected problem if thats the case then prolly what those other guys were saying. could be a completely different issue though. just my 2 cents. have a good one.

07-14-2011, 08:22 AM	#15
driftxninja Zilvia Member Join Date: Mar 2010 Location: Ventura Posts: 153 Trader Rating: (0) Feedback Score: 0 reviews	no problem man! very common issue with these 240s. as for the bogging that is a tough one... i would say that is most likely a fuel issue.. best thing is to do the cheap stuff first, like a new fuel filter like 10 bucks, check the fuel pump, make sure you have good fuel pressure, could try cleaning your injectors.

07-14-2011, 08:25 AM	#16
driftxninja Zilvia Member Join Date: Mar 2010 Location: Ventura Posts: 153 Trader Rating: (0) Feedback Score: 0 reviews	since you mentioned it bogs with like half a tank of gas does it bog with a full tank or less than half a tank? PM me for faster responses ok. looking online it could be a number of reasons it bogs... found issues like o2 sensor, fuel filter clogged up, your TPS (throttle position sensor) could be bad.

07-17-2011, 09:35 AM	#18
driftxninja Zilvia Member Join Date: Mar 2010 Location: Ventura Posts: 153 Trader Rating: (0) Feedback Score: 0 reviews	does it bog all the time or randomly ? i think you told me random in your PM im too lazy to check again right now. ,haha. so anyways does the motor shake when it bogs or anything weird happen? obviously the rpms drop i had a problem once where my fuel injector would cut out on me randomly and my engine would run on 3 cylinders till it decided to work again if it bogs down again i would try pulling over and looking at your engine bay, pull spark plug wires one at a time while engine is running, if you notice there is not any change in rpm after you pull one then that cylinder isnt firing. try that and let me know is it like a quick just bog down and then boom your good or do you have continuos loss of power afterwards?