fuel level necessary for evap to run properly
02-26-2007, 01:32 PM
#1
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fuel level necessary for evap to run properly im wokring on getting a california legal hybrid together. I have incorporated the single line fuel system from a corvette and am working on getting evap to work properly.
so far i KNOW:
i need a fuel level signal.
some evap functions only run at certain fuel levels.
i aint using a camaro fuel level sender in the tank (sorry smog guy)
evap cannister, plumbing and pressure sensor are functional.
purge valve on intake is functional
what i dont know:
can i reprogram the ecu to recognize a new fuel level sender range...ie can i tell the ecu that 3 ohm is full and 90 ohms is empty? or something like that? (ie reverse the scale and use my oem sender)
does evap work when tank is full of fuel, or must it see a certain fuel level before it energizes the purge solenoid.
is the tank pressure sensor signal required in a certain range to energize purge and vent solenoids, or do they work all the time.
is the fuel level sender associated with evap function or only with EVAP TEST AND READNIESS CHECKS?
any help appreciated....thanks!
so far i KNOW:
i need a fuel level signal.
some evap functions only run at certain fuel levels.
i aint using a camaro fuel level sender in the tank (sorry smog guy)
evap cannister, plumbing and pressure sensor are functional.
purge valve on intake is functional
what i dont know:
can i reprogram the ecu to recognize a new fuel level sender range...ie can i tell the ecu that 3 ohm is full and 90 ohms is empty? or something like that? (ie reverse the scale and use my oem sender)
does evap work when tank is full of fuel, or must it see a certain fuel level before it energizes the purge solenoid.
is the tank pressure sensor signal required in a certain range to energize purge and vent solenoids, or do they work all the time.
is the fuel level sender associated with evap function or only with EVAP TEST AND READNIESS CHECKS?
any help appreciated....thanks!
02-27-2007, 11:28 PM
#6
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Yes, you can calibrate any fuel sender to a Camaro donor gauge. You just need to reprogram it with HP Tuners and place your parameters for empty and full resistance. You can then program out the Evap so the check engine light will not go on. If you feel courageous, you can adapt the pressure sensor from the Camaro to your tank, but chances are it may not hold the pressure well enough and the whole "balance" will not be in factory range because of your evap setup, gas cap, etc.
I had to convert my Mustang sender to a positive switching system because the Ford system varied resistance from ground. The LS1 instead will vary resistance between a 5 volt positive signal and the return wire, both of which go to the PCM.
I had to convert my Mustang sender to a positive switching system because the Ford system varied resistance from ground. The LS1 instead will vary resistance between a 5 volt positive signal and the return wire, both of which go to the PCM.
02-27-2007, 11:37 PM
#7
If you calibrate the pcm to recognize the resistance range of the oem sender in the vehicle it is working in then how do you get your stock gauge to read correctly. I had the same problem on my s-10 all I had to do was send five volts through the stock sender and reprogram the pcm to recognize and all of the evap would work. But, then my stock gas gauge would not have worked because it was like your mustang and used a ground to the sender and then the gauge varied off of the resistance it received from the sender. If anyone has a definitive solution for this I really would like to know it. This is the main reason I scrapped the evap diagnostics on my s-10. I left all of the canister and evap purge solenoid functioning I just disabled all of the diagnostic tests and codes and had them set all of the monitors to yes. We do not have emmissions testting but it would pass a visual if it had to. On the plus side the evap canister is under the bed on the s10 so no one would look there anyways.
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02-28-2007, 09:17 AM
#10
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I'm planning on running the EVAP canister and the purge valve, but disabling all of the diagnostic codes and test in the computer just like 01WS6/tamu did. I don't really see the need to have all the diagnostic functions working anyway, unless they test those in California. As long as the EVAP still functions like normal I would think you are fine.
03-01-2007, 06:50 AM
#12
I get two codes for the EVAP in my 87 swap. I didnt send fuel level to the PCM because I didnt think that I needed to. Both codes are saying there is no fuel level signal. Im assuming that its causing my evap to not work properly...and Ill be hooking that up as soon as the weather gets nice enough to really start wrenching again.
Anyone know if there are any ill running effects from the EVAP not working properly? Or will it caused poor MPG or anything?
A couple people just told me to leave it...but its one wire. So Im gonna just hook it up. Im also going to get one of those programmable fuel level gauges...
J.
Anyone know if there are any ill running effects from the EVAP not working properly? Or will it caused poor MPG or anything?
A couple people just told me to leave it...but its one wire. So Im gonna just hook it up. Im also going to get one of those programmable fuel level gauges...
J.
03-01-2007, 09:28 AM
#13
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There should be no ill effects to not having the EVAP working. Guys on this forum remove the whole system everyday, so I don't think you're losing anything by not having it. In your situation, I would just have your tuner remove the diagnostic checks for the EVAP system so that it will function without the need for a fuel level reference from the tank.
03-01-2007, 01:10 PM
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i have to run it to be legal in california.
I completely disagree with the idea that here are no drawbacks to deleting evap. I'm hardly a greeny, but there is simply no excuse for gratuitous pollution with no performance benefit. Further - if you simply vent to atmosphere, from under the car, you are probably inhaling the light aromatic hydrocarbons that offgas from the fuel.
they are phenomenally posionous.
I completely disagree with the idea that here are no drawbacks to deleting evap. I'm hardly a greeny, but there is simply no excuse for gratuitous pollution with no performance benefit. Further - if you simply vent to atmosphere, from under the car, you are probably inhaling the light aromatic hydrocarbons that offgas from the fuel.
they are phenomenally posionous.
03-01-2007, 03:17 PM
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Yes, obviously, it's very harmful to the environment - no argument there. I thought he was referring to the performance of the engine being affected by the removal of the EVAP. There should be little, if any, difference with, or without the EVAP system in place with regards to the performance of the engine.
03-02-2007, 06:53 AM
#16
nickel.. You were correct. I was referring to the performance of my engine not the output of emissions. I would just have it tuned out...but I ran a line for it, ran wires for it, and left the tank intack for it. I might as well hook up the one wire left (fuel leve) to get it working properly. Although I do like simplicity and ditching all that stuff in the engine bay would look better.
As far as emsissions goes... I dont drive the car over 5000 miles a year. EPA says thats good enough to be emissions exempt. So its no different if I ditch the EVAP and run a vented tank than the guys running around in 60's muscle cars. Actually..it probably is better because our newer engines are much more efficient than the old Gen I motors.
But Ill just hook mine up and make it work. Seems to be the easiest thing to do right now. Haha...besides..my tuner is going to have enough on his plate.
Justin
As far as emsissions goes... I dont drive the car over 5000 miles a year. EPA says thats good enough to be emissions exempt. So its no different if I ditch the EVAP and run a vented tank than the guys running around in 60's muscle cars. Actually..it probably is better because our newer engines are much more efficient than the old Gen I motors.
But Ill just hook mine up and make it work. Seems to be the easiest thing to do right now. Haha...besides..my tuner is going to have enough on his plate.
Justin
03-02-2007, 10:10 PM
#17
I left all of the evap functioning on mine including the canister. I just deleted all of the diagnostic crap that is a PITA and had them set the monitors to yes. If the evap monitor says yes it will pass bc you have your tuner set it that way, and that is all that is required. If you install the evap can and purge solenoid and set the monitors to yes it should pass even in nazifornia. The problem that lead me to do it on mine was the fuel level signal difference and keeping my stock gas gauge working. It was already on my truck from the factory so I left all of the wires in the harness I made, if I decide in the future to dork with it it's allreadt there. Even if it does pollute a little there are way more cleaner cars on the road so it evens out in the end.
