Why does the gas pump cut off every few cents at the fill-n station.
Asked by sc6501 Mar 11, 2015 at 11:37 AM about the 2007 Chevrolet Trailblazer
Question type: Maintenance & Repair
I have a 2007 Chevrolet trail blazer. At the gas pump you have to push the knob on the pump about 20 times every few cents to get a gas tank full. I took it to the dealer and they charged us $175.00 for the warranty charge and denied it acted up on them. It has acted upon me everytime I get gas. Do you know how we can get this fixed?
4 Answers
Often when this happens it's the EVAP vent. When you fill up, air and gas fumes are displaced, and instead of coming out in to your face and the air we all breathe the fumes are pushed in to a charcoal canister that soaks up the hydrocarbons and gets purged with intake vacuum when car is started. The fumes are also pushed back in to gas tank. So the pipe from the tank filler to the canister, OR back to recovery line to gas tank--- is blocked, or the valve that opens/closes it is stuck closed, or because that valve is not working the canister is not being purged and is saturated with liquid gasoline. It won't accept any air/fumes and the pump nozzle 'thinks' the tank is full. If your CEL is on, that's actually good, because it has thrown a code that may help point to part that has failed
This is a typical system, click for full screen ..note items 3 and 4
And there is more. If you use the same pump every time, the problem my not even be in your Trailblazer. If you really are interested, read this: http://leg.wa.gov/jlarc/reports/GasVaporReg/pf/default.htm
That is the old way for vapor recovery for pre-OBDII and the new emissions laws, and is being phased out and many States don't have it