420A Evap system

[AM2SS]

When does the EVAP ventilation solenoid on a 99 Mitsubishi eclipse GS no turbo get power so far mine does not have power when the vehicle is running key on key off and it's not allowing the vehicle to run properly all my fuses are good.

 

[Turbski91]

When does the EVAP ventilation solenoid on a 99 Mitsubishi eclipse GS no turbo get power so far mine does not have power when the vehicle is running key on key off and it's not allowing the vehicle to run properly all my fuses are good.

That solenoid will only get power when the computer tells it to. If you find someone with a snap on scanner you could activate it yourself. But I’m just curious why do you think this solenoid is making the car not run properly?

 

[AM2SS]

That solenoid will only get power when the computer tells it to. If you find someone with a snap on scanner you could activate it yourself. But I’m just curious why do you think this solenoid is making the car not run properly?

Because I have a check engine like that's the p0171 code which is lean conditions Bank 1 well I've only got a four cylinder cuz this is a 1999 eclipse GS no turbo. I have a new fuel pump fuel pressure regulator fuel injectors plugs wires coil pack EGR valve crankshaft position sensor camshaft position sensor both sensors on the throttle body all new gaskets from the head up timing a ton of stuff cuz I had a broken valve fixed everything ran great for a hot minute and now it hesitates and falls on his face if you floor it if you baby it it'll run okay it'll run pretty decent if you baby it but as soon as you put your foot in it flat on his face so it's something to do with the vacuum side and since the vacuum in the EVAP system are kind of linked on these things so I'm hunting for something that doesn't get power or is not working properly and today I found my solenoid that's in front of the passenger side wheel well behind the headlight turns off and on properly but there's no voltage at the plug and I don't know when the relay fires to tell it to turn off and on or open and close. Any questions or ideas?

 

[Turbski91]

Because I have a check engine like that's the p0171 code which is lean conditions Bank 1 well I've only got a four cylinder cuz this is a 1999 eclipse GS no turbo. I have a new fuel pump fuel pressure regulator fuel injectors plugs wires coil pack EGR valve crankshaft position sensor camshaft position sensor both sensors on the throttle body all new gaskets from the head up timing a ton of stuff cuz I had a broken valve fixed everything ran great for a hot minute and now it hesitates and falls on his face if you floor it if you baby it it'll run okay it'll run pretty decent if you baby it but as soon as you put your foot in it flat on his face so it's something to do with the vacuum side and since the vacuum in the EVAP system are kind of linked on these things so I'm hunting for something that doesn't get power or is not working properly and today I found my solenoid that's in front of the passenger side wheel well behind the headlight turns off and on properly but there's no voltage at the plug and I don't know when the relay fires to tell it to turn off and on or open and close. Any questions or ideas?

Are you sure you’re getting enough fuel pressure? That solenoid you’re talking about wouldn’t make the engine die like that. Was the car running fine before you did all those fuel system upgrades?

 

[BLACK'98DSM]

The purpose of the purge solenoid is to PURGE excess pressure. It only opens when the pressure of evaporated gasoline exceeds the maximum threshold programmed into the ECU. For example, when driving the vehicle and fuel is sloshing around it will create positive pressure which is relieved by the solenoid and recirculated into the intake manifold.

Having a lack of power would not cause your issue. Without voltage, the solenoid remains always closed. It opens intermittently as required. It's more than likely functional and you aren't able to detect voltage because voltage isn't necessary at the times you check for it. If the solenoid were not functioning, or even always open, you would get a fault code and CEL. Your fault code is not EVAP related and more than likely just a vacuum leak.

 

[AM2SS]

Yes, I put a PSI gauge on it and it is 48-52 PSI.
It ran rough and had and still has hesitation on acceleration, and you can't floor it. Has had multiple check engine codes I'm down to this one. P0171. And this evening I read that the temp sensor sends data to the computer which then makes adjustments from there. So I tested it and it is bad. Both are on order now. So what do you think?

 

[BLACK'98DSM]

How did you test the sensor and what were the results?

 

[AM2SS]

The purpose of the purge solenoid is to PURGE excess pressure. It only opens when the pressure of evaporated gasoline exceeds the maximum threshold programmed into the ECU. For example, when driving the vehicle and fuel is sloshing around it will create positive pressure which is relieved by the solenoid and recirculated into the intake manifold.

Having a lack of power would not cause your issue. Without voltage, the solenoid remains always closed. It opens intermittently as required. It's more than likely functional and you aren't able to detect voltage because voltage isn't necessary at the times you check for it. If the solenoid were not functioning, or even always open, you would get a fault code and CEL. Your fault code is not EVAP related and more than likely just a vacuum leak.

Okay, if it is only a vacuum leak. I looked at all of the lines etc...I even sprayed carb cleaner at all of the lines and etc and the engine didn't rev.up once. So what would be a better method?? I'm at a loss.

 

[AM2SS]

How did you test the sensor and what were the results?

I checked my sensor for the gauge with a voltmeter and I've got 59 ohms and supposed to have 13 and the one for my computer had like 500 and it's supposed to be way higher than that so I put two new sensors in and my gauge is working properly now and I still have a check engine light and it still hesitates when I floor it.

 

[Turbski91]

I checked my sensor for the gauge with a voltmeter and I've got 59 ohms and supposed to have 13 and the one for my computer had like 500 and it's supposed to be way higher than that so I put two new sensors in and my gauge is working properly now and I still have a check engine light and it still hesitates when I floor it.

The sensor for the gauge doesn’t affect the engine. You need to check the other coolant temp sensor.

 

[AM2SS]

The sensor for the gauge doesn’t affect the engine. You need to check the other coolant temp sensor.

I checked the other one too. It was way out of spec too. And the plug was crunchy with the connectors green and rotten.. I replaced the sensor and the pigtail. It runs better but still has a hesitation when you floor it.