I have a 1999 Ford Explorer with the V-6 SOHC that is stuttering and stalling when I try to accelerate. A very slight acceleration will get the vehicle moving, but anything coming close to normal gas pedal pressure causes immediate stuttering and/or stalling. Check Engine light came on when problem started yesterday.

Where is the EVAP System Canister Vent Solenoid? I bought a code reader after beating my head against the truck all afternoon and got code "P1451 EVAP System Canister Vent Solenoid Circuit Malfunction". My Haynes book says on the left side frame rail... can't find anything along there that looks like it (based on picture from Rock Auto for replacement part) and found some people online talking about it being in the engine compartment on the passeneger side... Just crawled all over the truck and I think I found the charcoal canister, but couldn't trace it back to the vent solenoid... There was something right next to the canister, but again, it looked nothing like the replacement part listed on Rock Auto...

 

http://info.rockauto.com/getimage/ge...tex/2N1116.jpg

This is what Rock Auto shows the part should look like.

 

Under the battery tray. Check wiring and connector for damage due to corrosion from battery acid.

 

Thanks...

Now that I've found it... I can't get to it without removing the battery and can't troubleshoot it with the battery out... Soooooooo Have to pull the faring from inside the wheel well out and go in that way...

I'm starting to weigh the options between how much time and hassle this stupid thing is worth and how much the shop is going to rob me for doing what should be a simple fix.... and I have not been able to find decent instructions on how to troubleshoot it or replace the part if it is shot... Haynes manual barely mentions the part is even in the fuel/emission system.... I hate messing with fuel stuff especially without specific instructions.......

That noise? That's me beating my head against the hood of my Explorer.........

 

Update...

Checked electrical connection, no major corrosion... used a little Deox It just in case...

Visually checked Vacuum line going into vent solenoid since I was under there... Looked good...

Got 12.1 volts at the connector with the key on/engine off

37 ohms on the part itself... I found another thread where someone said that it should have 50-60 ohms but that was for an F-150... Is that showing a problem or just a difference between the Explorer and F-150?

The code says that the part isn't working, so I guess I should replace it at this point... Now... $60 at Auto Zone or $30 from Rock Auto and wait a couple days..........

 

I sent you an email.
P1451 - EVAP Control System Canister Vent Solenoid Circuit Malfunction

Description
Monitors the canister vent (CV) solenoid circuit for an electrical failure. The test fails when the signal moves outside the minimum or maximum allowable calibrated parameters for a specified canister vent duty cycle by PCM command.

Possible Causes
VPWR circuit open
CV solenoid circuit shorted to PWR GND or CHASSIS GND
Damaged CV solenoid
CV solenoid circuit open
CV solenoid circuit shorted to VPWR
Damaged PCM

Diagnostic Aides
Monitor EVAPCV PID and voltage between canister vent solenoid signal and PWR GND in output test mode with key ON engine OFF (or in key ON engine RUNNING mode)
EVAPCV PID at 0% and voltage less than 1.0 volt (or EVAPCV PID at 100% and voltage greater than 0.5 volt) indicates a hard fault

 

Thanks for the info...

I can't do all the troubleshooting since I only have a basic codereader and no equipment to measure the pressure, but I think it's telling me that the resistance is too low... Trouble is, I'm used to resistance being correct or REALLY wrong... I'm getting a reading of 37 ohms when the acceptable range (according to the guide you sent me) is 48-65 ohms... Sorry for my ignorance, but I am just used to seeing resistance in range or my meter saying O/L meaning it's shorted out....

If throwing this $30 part at the vehicle doesn't fix it, I think this is going above my capabilities and the capabilities of my garage... Had to order from Rock Auto since no local shops had it... So frustrating for such a seemingly minor issue... I guess I could get a bunch of "Hyper-Miler" bumper stickers, drive with my flashers on all the time, and deal with all the horns and middle fingers...

 

Did you get this P1451 code fixed?

 

Not yet.... Just started a new job so I haven't had time to do any more work and catching up on bills so I haven't had the money to drop it in the shop... So I've been driving the back up vehicle... (98 Taurus, feels like driving a go-cart...)

The only other thing I was thinking about trying: When first checking for problems, i found a heat shield that had come loose and was hanging on the wires to the driver's side O2 sensor... It had worn through the insulation, so not sure if that could short out the sensor and cause all the problems...

I was trying to be logical and start with the first code, but I am still getting 11 or 12 codes, some of which I know are domino effects of the actual problem...

I'm out of town for Thanksgiving, so I won't get back to anything until middle of next week, but I will post any updates... I am just hoping it is not the PCM.......

 

OK. Just some info that I learned with a P1451 lately: The part under the battery tray is the Purge Solenoid, not the Vent Solenoid. The Vent Solenoid that drives the electrical P1451 code is located between the spare tire and the floorboard between the frame rails. You can see a wiring pigtal cross above the rear crossmember and tuck above a plastic tray with three bolts. The Vent Solenoid and I believe they are the charcoal canisters are located in this tray. It is a metal piece and doesn't have a diaphragm or filter like the Purge Solenoid. Both of the wires on my solenoid were broken at the connector. The resistance on this solenoid was in the 50s for mine, and the Purge Solenoid at the front was in the 30s, like yours. I fixed the wires and had 12volts at the solenoid, but after clearing the code it came back on. Haven't been able to look into it again yet.

Keep posting up if you get to look at it again.

 

jsmorris, you are correct. The FORD MANUAL is once again incorrect!!

 

I actually dropped that tray to check the connections and didn't see anything wrong, but I will definitely get back under there in the next day or two to check the wiring really well... As frustrating as it would be, it would be nice if it was just a bad connection back there.......

 

Tapper, since it seems we both have the same problem I thought I would post the link to my thread HERE. My latest: I have 12.1V at the connector and 55ohms across two different solenoids and both give me the code on the second start after a code reset.

 

Removed the whole tray just now... The vent solenoid is completely rusted on the outside, but reading 54.6 ohms, which is normal... Not getting any current from the connector when running... Is this supposed to have constant current or is it only on when needed? Crazy thing is that my real problem is the stalling upon acceleration which is still happening exactly the same way with the canisters and vent solenoid removed... The two tubes are not connected to anything and I still have the same problem, which tells me there is another problem..........

 

Curious to know what did you do to determine there is no current from the harness when the engine is started? Do you mean increased voltage? You can't measure current unless you have the solenoid hooked up and it is actually actuating. On mine the voltage on the one wire went from 0.04 to 0.07V and the other went from 11.6 to 14.4V when I started the vehicle. Those are both relative to frame rail ground.

Sorry, I do not know what the duty cycle is of this solenoid and at what conditions it will be open or closed.

I think the stalling is another issue completely. Do you have any other codes?