Removing my EVAP System in it's entirety...
10-20-2010, 01:42 PM
#1
Removing my EVAP System in it's entirety...
It seems so simple. The duties performed are to use fumes from the top of the gas tank so that basically nothing is wasted, correct? It filters what evaporates and sends the fumes into your intake. With the exception of emissions tests, what tells us that we can not work our way from the charcoal anister forwards eliminating everything and plugging fuel lines? Absolutely nothing, right? Any idiot could take this entire system out in an hour or so and save thousands on bull**** purge valve, canister, and cap replacements. Am I wrong?
10-20-2010, 02:49 PM
#3
See, the thing is, I'm not having any problem with mine, I just believe that there is no need for it and a block can easily be set up. Seriously, some clippers and colored tape and I'm good.
10-20-2010, 05:18 PM
#4
I actually just replaced my gas cap today because the 455 code (I know there's a 0 in there somewhere) for this system. I installed it in the Nissan parking lot and my SES went off before I even pulled in the driveway.
More on track with the thread......I would suggest talking with the guys who have done the 3.5 swaps.....Aaron would definately be the man. I sincerely doubt he adapted this system into his 3rd gen.
More on track with the thread......I would suggest talking with the guys who have done the 3.5 swaps.....Aaron would definately be the man. I sincerely doubt he adapted this system into his 3rd gen.
10-20-2010, 06:47 PM
#7
I don't like things in my engine bay that don't need to be there. Also, I don't like weight, or unneeded hard lines under my car that can leak and cause problems. Plus, I already used a full bottle of baby oil on my nether regions today, baby. You like?
10-20-2010, 08:08 PM
#8
10-20-2010, 08:16 PM
#9
baby oil? whaaa-..???
10-20-2010, 08:44 PM
#12
10-21-2010, 04:52 AM
#15
It seems so simple. The duties performed are to use fumes from the top of the gas tank so that basically nothing is wasted, correct? It filters what evaporates and sends the fumes into your intake. With the exception of emissions tests, what tells us that we can not work our way from the charcoal anister forwards eliminating everything and plugging fuel lines? Absolutely nothing, right? Any idiot could take this entire system out in an hour or so and save thousands on bull**** purge valve, canister, and cap replacements. Am I wrong?
Anyone?
10-21-2010, 05:41 AM
#16
It's part of your vehicle emissions management. The gasoline is in a closed system, meaning gas fumes don't simply dissipate into the atmosphere, they are instead filtered through the EVAP system and burned by the engine. It has nothing to do with making sure "nothing is wasted"... it's an environmental consideration.
Weight? If you want to yank something because of weight, get rid of your air conditioning. Or be brave and ditch your spare tire.
"Any idiot could save thousands..." What in the world are you talking about?
By all means, research this fully and come to your own conclusions. But since you're asking people for their thoughts on this, I think removing your EVAP system is irresponsible. And while I applaud your approach towards minimalism, you should probably direct those energies elsewhere.
Brilliant.
Weight? If you want to yank something because of weight, get rid of your air conditioning. Or be brave and ditch your spare tire.
"Any idiot could save thousands..." What in the world are you talking about?
By all means, research this fully and come to your own conclusions. But since you're asking people for their thoughts on this, I think removing your EVAP system is irresponsible. And while I applaud your approach towards minimalism, you should probably direct those energies elsewhere.
Brilliant.
Last edited by Rochester; 10-21-2010 at 06:53 AM.
10-21-2010, 08:52 AM
#17
I'm 100% for this thought as well, but not knowing any more yet, about the Max's codes and fail-safes, how do you go about preventing the CEL from coming on? I'm currently staring at those whatever-the-code-numbers are induced CEL for my EVAP system, and I'd love to turn it off without replacing parts. Along those lines, I'd love to just yank all that crap off, but don't know how to keep the CEL off.
Anyone?
Anyone?
10-21-2010, 09:11 AM
#18
Are you serious? How do you plan to eliminate the system from the ECU? Why would you spend so much time eliminate something that is working fine, that will definitely be far more hassle to remove than to just leave it alone? I'm sorry, but this just lacks any common sense.
S
S
10-21-2010, 11:23 AM
#20
Are you serious? How do you plan to eliminate the system from the ECU? Why would you spend so much time eliminate something that is working fine, that will definitely be far more hassle to remove than to just leave it alone? I'm sorry, but this just lacks any common sense.
S
S
So where's Aaron to chime in on this?
10-21-2010, 11:28 AM
#21
10-21-2010, 11:51 AM
#22
There is no way to eliminate the system in a vehicle that is equipped with it from the factory without triggering a MIL. The EVAP system prevents fuel vapor build-up in the sealed fuel tank. Fuel vapors trapped in the sealed tank are vented through the vapor valve assembly on top of the tank. There is no way around it. There are no ways to program the ECU to ignore it. Any attempt to rid the vehicle of this particular system for "weight" reasons would be a complete exercise in futility.
10-21-2010, 12:48 PM
#23
Robert, I've tried to briefly scan the FSM to familiarize myself with the operation of the system, but time's not on my side.
From my quick understanding, the CEL could only come from the system pressure sensor. I'm thinking that when your control valve sticks open, your gas cap fails or is left loose, or your canister cracks, then of course, the system can't maintain any pressure, and the CEL is triggered by the ECU.
If it's really that simple, then just bypassing the control valve and canister by joining the air lines in/out, and locking an appropriate amount of air pressure in the system, would fool the computer sufficiently to keep any CEL at bay, and continuing with complete removal of the system would just be more work and not necessary. There must be a suitable pressure range that the ECU is looking to operate in, and too much pressure (purge valve stuck shut) or too little pressure (see examples above) will generate the CEL.
The purge control valve solenoid must be the recipient of whatever computer power signal is generated by the pressure sensor, and possibly merely a "ride-along" in CEL generation, as, as far as I can tell, it can think it's regulating the purge valve all day long, and wouldn't know that the valve has failed, if the system pressure sensor doesn't tell it anything, so it wouldn't trip a CEL.
Generating the CEL has to be up to the system pressure sensor, which could easily be fooled into thinking everything's hunky dory, and voila, no more CEL. I'm going try that approach first, to save myself the cost of the valve and more than likely canister, to clear my current CEL. It'll be pretty easy, free, and reversible if ineffective, so there's my decision made for me.
From my quick understanding, the CEL could only come from the system pressure sensor. I'm thinking that when your control valve sticks open, your gas cap fails or is left loose, or your canister cracks, then of course, the system can't maintain any pressure, and the CEL is triggered by the ECU.
If it's really that simple, then just bypassing the control valve and canister by joining the air lines in/out, and locking an appropriate amount of air pressure in the system, would fool the computer sufficiently to keep any CEL at bay, and continuing with complete removal of the system would just be more work and not necessary. There must be a suitable pressure range that the ECU is looking to operate in, and too much pressure (purge valve stuck shut) or too little pressure (see examples above) will generate the CEL.
The purge control valve solenoid must be the recipient of whatever computer power signal is generated by the pressure sensor, and possibly merely a "ride-along" in CEL generation, as, as far as I can tell, it can think it's regulating the purge valve all day long, and wouldn't know that the valve has failed, if the system pressure sensor doesn't tell it anything, so it wouldn't trip a CEL.
Generating the CEL has to be up to the system pressure sensor, which could easily be fooled into thinking everything's hunky dory, and voila, no more CEL. I'm going try that approach first, to save myself the cost of the valve and more than likely canister, to clear my current CEL. It'll be pretty easy, free, and reversible if ineffective, so there's my decision made for me.
Last edited by BlackMacks; 10-21-2010 at 01:11 PM. Reason: clicked submit too soon
10-21-2010, 01:21 PM
#24
Just discovered a flaw in my thinking: every time you were to remove your gas cap, your sealed system would de-pressurize, and you'd need to "recharge" the pressure. Sounds like a PITA to address repetitively, hmm....
10-21-2010, 01:32 PM
#26
10-21-2010, 02:38 PM
#27
Ugh, I'm overthinking the solution to my problem, as usually is the case......
Reading the FSM, if I'm understanding it correctly, the ECM is expecting a voltage signal to terminal 60 of 3.4V, which appears to correspond to the system pressure sensor's output of roughly .3-.4 psi. This keeps the CEL from being set, because the system's integrity isn't compromised, as it's able to hold pressure.
So, leave all the broken parts alone, jumper a 12V ign-on signal, with a suitable resistor in-line, to said terminal of ECM, cut the wire from the sensor, and you're done.
I think.......
Reading the FSM, if I'm understanding it correctly, the ECM is expecting a voltage signal to terminal 60 of 3.4V, which appears to correspond to the system pressure sensor's output of roughly .3-.4 psi. This keeps the CEL from being set, because the system's integrity isn't compromised, as it's able to hold pressure.
So, leave all the broken parts alone, jumper a 12V ign-on signal, with a suitable resistor in-line, to said terminal of ECM, cut the wire from the sensor, and you're done.
I think.......
10-21-2010, 02:43 PM
#28
Jesus...either everyone is over-thinking this or not at all.
Effectively if the OP eliminates it from the car he will throw an MIL, SES, or check engine light (whatever you want to call it).
OP said he would look at eliminating it from his ECU? WTF? Obviously way too much time on your hands to be thinking about something as pointless as this.
Effectively if the OP eliminates it from the car he will throw an MIL, SES, or check engine light (whatever you want to call it).
OP said he would look at eliminating it from his ECU? WTF? Obviously way too much time on your hands to be thinking about something as pointless as this.
10-21-2010, 07:42 PM
#29
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10-22-2010, 05:28 AM
#30
"In my 92 Maxima VQ35, I am not running an EVAP system since I am not effected by any emissions standards in my area. So, I definitely have an EVAP code showing on my ECU, but it’s no problem."
"I don’t see any reason why EVAP would affect performance or HP output. It only prevents fuel vapors from entering the atmosphere.
I removed my EVAP system completely to reduce engine bay clutter and weight. I am not effected by OBDII emission standards since I have a 92 Maxima."
We talked earlier.
Every time you took off your fuel cap, you released build up into the atmosphere.
10-22-2010, 08:04 AM
#31
That's a good point, Robert, I could seperate the pressure sensor from the EVAP system, and just dead head a half psi to it, so it sends the appropriate signal to the ECU. Keeps me from dealing with anything electrical.
I don't think the solenoid even needs to be touched, to be honest, as it can be allowed to think it's regulating the purge valve all it wants, and as long as the ECU is seeing the correct signal from the sensor, no CEL.
My idea for sending that 3.4V signal to terminal 60 of the ECM would be the way for you to approach removing the EVAP system in its entirety, without fear of the CEL, but I'm not that gung-ho against the system, I just want the light off without shelling out bucks for the parts.
I don't think the solenoid even needs to be touched, to be honest, as it can be allowed to think it's regulating the purge valve all it wants, and as long as the ECU is seeing the correct signal from the sensor, no CEL.
My idea for sending that 3.4V signal to terminal 60 of the ECM would be the way for you to approach removing the EVAP system in its entirety, without fear of the CEL, but I'm not that gung-ho against the system, I just want the light off without shelling out bucks for the parts.
10-22-2010, 09:23 AM
#32
Fuel vapours present in an empty tank are forced out during tank filling, and are recovered by the EVAP system, as well as during regular operation of the fuel system.
10-22-2010, 09:38 AM
#33
1967
10-22-2010, 10:10 AM
#34
10-22-2010, 10:42 AM
#35
And I'm right there with ya on age...
...give or take a year [or 5]
Last edited by nismopc; 10-22-2010 at 10:50 AM.
10-22-2010, 11:29 AM
#36
That's a good point, Robert, I could seperate the pressure sensor from the EVAP system, and just dead head a half psi to it, so it sends the appropriate signal to the ECU. Keeps me from dealing with anything electrical.
I don't think the solenoid even needs to be touched, to be honest, as it can be allowed to think it's regulating the purge valve all it wants, and as long as the ECU is seeing the correct signal from the sensor, no CEL.
My idea for sending that 3.4V signal to terminal 60 of the ECM would be the way for you to approach removing the EVAP system in its entirety, without fear of the CEL, but I'm not that gung-ho against the system, I just want the light off without shelling out bucks for the parts.
I don't think the solenoid even needs to be touched, to be honest, as it can be allowed to think it's regulating the purge valve all it wants, and as long as the ECU is seeing the correct signal from the sensor, no CEL.
My idea for sending that 3.4V signal to terminal 60 of the ECM would be the way for you to approach removing the EVAP system in its entirety, without fear of the CEL, but I'm not that gung-ho against the system, I just want the light off without shelling out bucks for the parts.
10-22-2010, 11:52 AM
#37
I was thinking of something just as simple as tearing the steel inner guts out of an old tire valve stem and clamping it inside the hose feeding the pressure sensor, then shooting it with a half psi and calling it a day. The pressure sensor doesn't have a relief valve, as far as I've read, it's sealed, so if you isolate it from the EVAP system and force it to generate that .2-.6 psi signal that the ECM is looking for, you're home free.
After that, the rest of the system can do whatever the hell it wants to, but as long as that terminal 60 is seeing 3.4V, no CEL. That's all I'm gonna do, so I'll let ya know if it keeps my CEL off.
Unless you beat me to it....
After that, the rest of the system can do whatever the hell it wants to, but as long as that terminal 60 is seeing 3.4V, no CEL. That's all I'm gonna do, so I'll let ya know if it keeps my CEL off.
Unless you beat me to it....
10-22-2010, 12:18 PM
#38
I was thinking of something just as simple as tearing the steel inner guts out of an old tire valve stem and clamping it inside the hose feeding the pressure sensor, then shooting it with a half psi and calling it a day. The pressure sensor doesn't have a relief valve, as far as I've read, it's sealed, so if you isolate it from the EVAP system and force it to generate that .2-.6 psi signal that the ECM is looking for, you're home free.
After that, the rest of the system can do whatever the hell it wants to, but as long as that terminal 60 is seeing 3.4V, no CEL. That's all I'm gonna do, so I'll let ya know if it keeps my CEL off.
Unless you beat me to it....
After that, the rest of the system can do whatever the hell it wants to, but as long as that terminal 60 is seeing 3.4V, no CEL. That's all I'm gonna do, so I'll let ya know if it keeps my CEL off.
Unless you beat me to it....
10-22-2010, 12:45 PM
#39
Wow, yeah, pretty soon you two are gonna be starting How-To/DIY threads like "How to install wheelchair lift in 5.5 gen Maxima" or "Buick Lucerne Front End Conversion"
10-22-2010, 12:52 PM
#40
The gorgeous Pontiac Can/Am comes to mind:
