92' Ranger XLT with 2.9 V6. My truck failed the pressure test part of emissions inspection. It's probably the fuel tank filler neck since I saw cracks in the rubber last year. I already have the part standing by.
But I might also replace the vapor hose that leads to the charcoal canister in the engine compartment. It's very old

There are three fuel or vapor lines in the attached photo. Can you tell me which ones are for vapor? The two metal L-shaped lines are mounted on top of the fuel pump

(I cut an access hole in the bed to make fuel pump servicing easier)

 

Just the one by itself is for EVAP system

The other 2 are OUT to fuel filter, and RETURN from Fuel pressure regulator(FPR) on the engine

That one line, by itself, runs to the charcoal canister in the engine bay you can unplug it at the canister end and blow into that line and tank should hold pressure, gas cap on, if it doesn't then leak is in the tank and yes could be filler tube, if you have a helper they can blow and you can listen
Do not use an air compressor for this, just lung power, so under 2psi

There is a 12volt solenoid on the other line running to the charcoal canister, also a pressure sensor, in the engine bay
You can test the solenoid with 9volt battery or 12volt, it has no polarity just + and - volts and you should hear it CLICK

 

Ron,

I might be wrong. But I don't think my charcoal canister has any solenoid, pressure sensor or electronic function to it. I believe that is for 95'and later (EEC-V). I did a little reading.
Your response is very helpful. Chilton's doesn't explain everything.

I'll probably replace the filler neck and the charcoal canister hose. And if I can find it, maybe that white cap with three ridges (for the charcoal canister hose) on top of the gas tank.

 

Solenoid would be on the hose that runs from canister to upper intake vacuum manifold

BUT yes, older systems did use a Ported Vacuum source and no solenoid, that hose would run to throttle body and connect to a port in front of the throttle plate, so low vacuum when engine is running

How are you failing the "test"?
Is it a code or are they testing gas tank directly?

 

In Arizona, for my make/model/year they test the gas tank and fuel system directly. It failed the fuel system pressure test. It looks like they attach probes or sensors to do all the required tests on my old vehicle. They also run the truck on this treadmill-like contraption.

My vehicle failed emissions about six years ago for the same thing. It was the fuel tank filler neck back then. This current one has multiple cracks. So I hope that's all it is. I have till the end of the month to take the retest.
I'll follow up with this soon.

 

I got my emissions problem fixed. I ended up replacing fuel pump filler neck and entire fuel evap hose. Also, one of the fuel pump locking ring tabs was not locked under the notch on the ramp. I tapped that into place with a rubber mallet and a drift punch.
I passed emissions on the third attempt. Thanks

 

Good work

Thanks for the update and FIXES