In the past on several occassions I had CELights due to Evap Leaks on my 97 Caravan 3.3.

One was from a small leak the other from a major leak. I have in the past found and repaired Evap System leaks due to bad hoses. They were always straight forward & located in the hoses up under the driver's seat area around the pump & valve/box area. This does not seem to be the case this time.

I was wondering if anyone knows if it is possible to pressurize the fuel tank (with low pressure through the cap) so that the pressure would feed back toward the engine, causing a hissing sound enabling an easier way to pinpoint the system leak.


Due to physical limitation from health issues, I am trying to avoid placing the van up on 4 stands & removing obstructions to hand & visually inspect every line in the Evap/Fuel line system.

It seems to me that this should be possible by adapting an old cap to put the air into the tank, but I do not know if this approach could damage any parts.

Any input would be appreciated.

 

Did you check for codes again? Are you sure this is an evap code again? I don't think you can put enough pressure in system to hear anything without doing damage. But if you havent been under it again are you sure its not another hose spit. that is a common problem. they will look fine sometimes but when you look close they can be split where they go onto the fittings, Sometimes they are even hard to find with a smoke machine

 

Check the tubing from the purge solinoid to the throttle body. They are known to crack there too.