Hello all, new here but have a 97 B2300 2.3 since last year.


I'm having an issue with the EVAP system and am curious about the function of the solenoid.


I have 12v at the solenoid connector with the key on and 0v with key off. I got a couple of spare solenoids at the yard along with another solenoid pigtail connector. With battery power across the spare pigtail connector, all of the solenoids energize.


Thinking that my original connector may not be making a good connection, I cut it off and wired my known good spare into place. Turned on the key, none of the solenoids would actuate.


My question is: Is the solenoid supposed to be energized (open) the whole time the key is on, or does the PCM/ECM open and close the solenoid during the course of driving the truck?


If it's supposed to be energized the whole time, then the current is low at the connector which would be a PCM issue, correct?


Thanks for any help!

 

my 1997 2.3 SuperCab with CEL P1443

I just replaced my cracked brittle vacuum line from the intake manifold to the charcoal canister. It had hardened so much that I had to slit it a few times with a blade and peel the crumbling mess off of the fitting with pliers. The fitting is so huge on the canister that I had to use a much bigger hose on it and shove the smaller hose (that goes the rest of the way to the intake manifold) into it. The second hose that leads to the hardline in the frame to the gas tank seemed fine even though it is 20 years old.

I am convinced that the vacuum line connected to the intake manifold is exposed to a lot more gas fumes and deteriorates a lot faster. I was tempted to replace the line with polyurethane tubing (that I use on my ATV's) which holds up to gas a lot better, but I was not sure it could handle the heat under the hood.

For years the idle on the Ranger would jump up and down at a stoplight and after changing that vacuum hose, it was really steady. To bad I am not a better mechanic and checked for a vacuum leak a long time ago.

I need to drive 100 miles without the Check Engine Light showing up to see that I fixed the P1443 problem. That could take a while because most of the time, my Ranger sits under a tree in the back yard.

 

Yes, EVAP code can take a week or so to test and clear.

Best method is to keep fuel level between 1/4 and 3/4, don't fill it up and don't run it below 1/4 tank.

Drive it longer than 20 minutes if possible, 15 minutes on highway with no stopping is best.

EVAP system must pass no leak and working test at least two times on two different drive cycles before it will clear code.
One drive cycle is full warm up, coolant temp above 185degF, 10-15minutes, and full cool down Coolant sensor below 100degF, about 3 or 4 hours of sitting depending on outside temp.

Problem is you can not force an EVAP test, computer does it when it wants, I think a Ford dealer can reset it but not force a test

 

So it sounds like if I fixed the problem with the new vacuum hose and I cleared the CEL with my OBDII checker, I may get the CEL again even though the problem is solved, until the EVAP test does it's thing.

The main reason that I posted about my experience was that I suggest anyone dealing with the P1443 change the vacuum hose between the charcoal canister and the intake manifold first, even if they cannot see a crack, unless that hose was recently changed or is very flexible and fresh looking.

I always start with the cheap and easy stuff first to try to make it easy on myself.

 

Yes, EVAP and other emission's codes will cause CEL to come back on until computer has tested system and cleared code, emission codes can't be cleared with regular reader/scanner, neither can Long Term Fuel Trims(LTFT).
CEL will go off on its own after computer is satisfied that problem is fixed, sometimes when driving but usually on next startup after testing was complete and passed.

 

CEL came back on after 25 miles after it was reset by the OBDII reader. CEL off after stopping at 35 miles and has not come back on.

I think I am past it now.

 

Right, OBD reader can't clear EVAP codes from memory, just from current code list, so CEL will come back on until computer has test system a few times.

Glad it is off now, good work

 

Similar issue here, solenoid was stuck open, replaced, ECL out for about two months then came back on. Replaced sensor, pulled battery cable for 5 min, ECL out at startup then back on after 50 miles. Research says solenoid off at idle, kicks in above idle. I have 12 volts to the solenoid key on running or not. Strange thing is when I ground the meter common wire to the battery it's 12 volts but when hooked to the black w/yellow stripe I get six volts and will rise with rpm but the solenoid will not open as the vac guage I have in the end of the hose shows nothing. A direct 12V to solenoid opens it. It's like a bad connection with not enough amps to operate the solenoid. I assume the blk wire goes to the ECM. For now just trying to get the solenoid to open, hoses seem fine. ???????????????

 

Most electric things, like solenoids, relays and fuel injectors, in cars, get 12volts when key is on, the Ground connection is what is controlled by the computer.
Because the 12volts is local, in engine bay, it is just safer to run Ground wires to computer where ever it is, a short won't melt a wire or blow a fuse.

So EVAP solenoid should have 12 volts with key on, then the computer will Pulse the Ground to open it a little or alot.
Pulsed Voltage is a common variable control in cars as well, IAC(idle air control) valve uses that.
When you Pulse the Ground(or 12volts) you can open a solenoid a little or alot, similar to a light dimmer but not voltage up and down.
The Pulse powers and unpowers the solenoid so, in effect, it is "vibrating" against spring pressure at a 1/4 open or 1/2 open or 3/4 open
If you hooked up a voltmeter it might look like lower voltage, it would depend on the meters electrics.
An analog meter, needle and gauge, would probably show you the pulsing, needle would vibrate.

 

It did finally open and if I am getting pulse as you describe, this would explain the solenoid vibrating as I hold it in my hand with increased rpms. I would assume this part of the system is now operating properly. When I started testing this today I do not think it was working. Will drive this week and see what happens. Thanks for the reply Ron, you seem to be the Guru on this Evap system

Dick

 

FYI purge sensor, I bought a Standard Products replacement CP416 which according to the auto parts store is the replacement cross reference. It is not, my P1443 code changed to P1445, high current flow at the sensor. ( bought a scanner over the weekend too) Finally found a "WELLS" brand #PV342 which has the same Ford logo and numbers as the one I removed. Now going through the cycles to see if the @#$*& CEL light will stay off.

Dick

 

Hmm, new purge sensor doesn't hold vacuum. Plug canister end, vac pump on other end and it steadily bleeds off. The old one bleeds slightly so neither holds vacuum. Back to the auto parts store.