Please settle this question

[Paisano]

The emissions technician said the failure is confined to the fuel evaporative system anywhere from gas tank to charcoal canister in engine bay.
I visually inspected this entire segment, including top gas tank connection points, and the only thing I found so far was cracks in the rubber fuel tank filler neck.

The failure falls under evaporative system/pressure test category

This weekend I'd like to improvise some type of smoke or soap bubble test too.

The truck, honestly, runs like new right now (I'm a stickler for maintenance and repairs)

The moderator asked for a couple good pictures. Absolutely. But there is a lot to cover in the engine compartment.
What specific locations to you want me to focus on in the engine bay?
2 pictures........3 pictures ?

 

[Shran]

https://www.amazon.com/dp/B0BGB41DLK?tag=959media-20

Snag one of those & some baby oil for your smoke test. I wonder if they smoke tested it and found some leaks...? That would explain the fail.

IMO if it was the purge solenoid at fault they should specifically say "purge solenoid inoperative" or something to that effect. A general failure in that area would be cause for me to replace the filler hose and have it retested.

So glad I don't have to deal with this nonsense.

 

[Paisano]

Still want pics of the engine bay?

how much psi needed for the test for cheaper option?

I already have a new tank filler neck and inexpensive fuel tank vent valve waiting in the garage.

(I complained to the state legislature in the past to exempt older cars from emissions testing. It's a nuisance every 2 years and it's not worth the burden it puts on people)

 

[lil_Blue_Ford]

On my 4.0 it’s there right behind the new AC compressor and connects to the throttle body. I’m missing a cap on my charcoal canister though.

Better shot of it hiding back there.

 

[alwaysFlOoReD]

I recently bought a cheap smoke machine. I was originally going to make my own but got impatient, and the savings would be $50 or less for me. Pressure is supposed to be about 1psi apparently. Not sure where I found that #.

 

[Paisano]

Thanks for the photo. That is helpful.
I don't know if the smoke machine is worth it.
I wonder if I can get my air compressor to run at less than 5 psi.

I looked again at the inspection report. The only failure is 'pressure test'
It passed every other category including gas cap.

 

[alwaysFlOoReD]

Cracks in the gas tank fuel line would leak pressure. Maybe start with replacing that line?

 

[lil_Blue_Ford]

Thanks for the photo. That is helpful.
I don't know if the smoke machine is worth it.
I wonder if I can get my air compressor to run at less than 5 psi.

I looked again at the inspection report. The only failure is 'pressure test'
It passed every other category including gas cap.

Glad it helps.

Most compressors don’t really regulate super low. Most of the smoke machines that I’ve seen have their own regulator to get the pressure below the minimum that the compressor will do. Or you can get a smoke machine with a built in compressor. I’ve been thinking of getting one of those because I don’t always have an air compressor handy to use a smoke machine.

 

[Paisano]

Ok. I'll look into economical vapor leak detection and I'll look at the fuel line also as suggested by one of you.

Here is a pic of the top gas tank. If you look close, you can see cracks in the filler neck.
Also, see that ridged white cap thing with the vent hose? That's the fuel tank vent valve.
I've heard those can be hard to remove. I ordered a replacement. The existing one is extremely old.
Do I just pry up the old one ?

 

[lil_Blue_Ford]

Ok. I'll look into economical vapor leak detection and I'll look at the fuel line also as suggested by one of you.

Here is a pic of the top gas tank. If you look close, you can see cracks in the filler neck.
Also, see that ridged white cap thing with the vent hose? That's the fuel tank vent valve.
I've heard those can be hard to remove. I ordered a replacement. The existing one is extremely old.
Do I just pry up the old one ?

View attachment 138207

Those vents just pry up out of the rubber grommet. Sometimes the grommet needs replacing.

 

[Shran]

The grommet part number for anyone interested is F6TZ9B076AA

Kind of a hard to find part for some reason but there's lots of them on eBay.

 

[lil_Blue_Ford]

The grommet part number for anyone interested is F6TZ9B076AA

Kind of a hard to find part for some reason but there's lots of them on eBay.

I got a new grommet from Bronco Graveyard along with the valve when I replaced the tank in my Choptop

 

[Paisano]

Good reminder. I didn't stop to think the grommet/seal might not come with the part.
I purchased Dorman part number 926-820 about 10 minutes ago.

 

[Curious Hound]

And, for a little more reference, here is a photo of my pirge valve and line going to the charcoal canister. 93, 3.0l