Jump to content

Fuel cap has a lot of air coming out, and terrible gas mileage


Bjankins1

Recommended Posts

So my gas mileage suddenly got way worse and every time I take the fuel cap off, there is a bunch of built up pressure, do these cars have purge canisters

The car is a 92 cutlass coupe 

Link to comment
Share on other sites

Verify fuel tank venting.

I've seen charcoal canisters fill up with liquid fuel because the purge valve doesn't work right.

Wouldn't hurt to connect a scan tool to see what the O2 sensors are showing.  I'd expect "rich" code(s) if the vent/canister system is failing so that the engine is pulling in excess raw fuel.  While you're in there, verify ALL sensors, and might as well check the fuel pressure, too.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...