phaze426

With winter weather now upon us here in NJ, my son has been running the heat in his 1990 Base Coupe when driving it. I've noticed when the heat is on there's a fairly substantial fuel smell inside the cabin. He parked it one day after a drive and I had him pop the hood so I could sniff around. It seemed like the smell was strongest around the vapor canister up under the driver's headlight, so I suspected something was going on there.

I found a cracked vacuum line for the EGR valve and repaired it after looking at the diagram and finding that it also supplied vacuum to the canister purge valve.


Here's a diagram of the EVAP/vacuum hoses showing the shared connection between EGR and canister purge.

Ran the car like that for a week or two and found that the gas smell was not diminished, so I started to suspect that the canister itself had failed or the rubber lines connected to it were so old they had become porous.

I pulled the canister out this past weekend and starting checking things out. I found that the purge valve still seemed to be good (would hold vacuum on the operator port and block/allow flow depending on whether it was actuated). Tried blowing up through the vent line on the bottom and a stream of tiny charcoal particles blew out the top line (that would route to the tank vent). This leads me to a few questions I was hoping someone could shine light on:


The charcoal pieces that came out were tiny and pulverized. Did they start off like this or is this the effect of years of vibration? I wondered if they began life as the "pellets" you might find in aquarium filter charcoal.

Should the charcoal/carbon be able to escape out the tank vent line? I would have suspected there was some kind of filter or screen on the top ports that would prevent that and perhaps it's deteriorated/failed, but then I considered that maybe I just exceeded a reasonable CFM of airflow from the vent by blowing into it?

It looks like the original Vapor canister (Delco 215-155) is no longer available since it had a fairly unique integrated purge valve. Has anyone had success integrating an aftermarket canister into the car and using an external purge valve? There seem to be tons of purge valves on the market, but all appear to be about the same size (maybe port size is slightly different). Anyone have any experience with if it matters which purge valve I select? Do they have different operating points for how much vacuum is supplied before they open?

Assuming I proceed with this retrofit, I'll try to document here with some pictures since I've definitely seen some other posts where folks have had these vapor canisters fail.

Thanks in advance for any help/insight.

JD1964

Try an experiment if you can’t find a proper vapor canister. Buy an extra gas cap and drill a couple small holes in the inner portion to make it a vented cap. Then plug the vapor canister lines. Vapor buildup would then vent out of the cap instead of under the hood and help keep the fumes from getting into the interior. It’s an easy experiment that can easily be undone.

phaze426

Thanks for the suggestion. I may opt for that as the ultimate solution if I'm unsuccesful in rigging up a different canister. In principle, I like the idea of an EVAP system. It's better for keeping things from smelling like gas and has no real negative performance impact when it's working properly. I'm just stymied like in so many other cases by him having a 1990 that had lots of one-year-only parts that are therefore unavailable now in the aftermarket.

phaze426

Just figured I'd provide an update in case anyone is interested. I ended up biting the bullet and retrofitting in a slightly different style canister. The original canister for the 1990 (ACDelco 215-155) had an integrated purge valve on the top of the canister along with a vent port on the bottom that went to a tee with two lines that just hung under the car to allow for purge air to flow in. I ripped out all the old stuff. Hoses were all pretty brittle and shot and not worth reusing.


Ditched the old canister and all the hoses, but ended up reusing the tank pressure control valve and purge solenoid pictured here since they seemed to be good.

I ended up picking up the following to replace the original canister:

ACDelco 215-153 Purge Canister (Easily available - even Amazon carries them)
ACDelco 214-2294 Canister Purge Valve

The system has a ridiculous number of individual hose/line sizes to make all the connections. I made some of the transitions by taking a heat gun to the hose to make it pliable and coercing it onto the larger fittings. I made others with adapter fittings.

Final result turned out okayish:


New EVAP canister and hoses. You can see the external purge valve strapped to the top with a zip tie. There's some sticky tape underneath of it as well. Seems to be secure enough for now.

Instructions for the new canister said that if you previously had a bottom vent, you can just use the "splash cap" you can see on the unconnected port on the top, so I went with that rather than plumbing back in vent hoses.

As I was wrapping things up, I found a cracked hose connection right at the transition from the metal vent line from the tank which may have been the source of the smell up in this area anyhow, but now everything is new and should be operating correctly, so I guess it's still one for the "win" column...

Still a strong fuel smell in the engine bay, however, but I'll start another thread to beg for help troubleshooting that.

seastman

How’s this setup working out for you a year later? Any new suggestions?

phaze426

It did seem to eliminate the fuel smell from up near the canister area. No EGR warnings came back, so vacuum must be holding relatively intact. All-in-all, I'd call it successful. There's still a fuel smell around the car that I haven't been able to chase. Might be a leaky injector leaving some fuel pooling in the intake is my next guess.