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02 Cougar fueling up slow

I have a 2002 Mercury Cougar and ever since i bought it (8 months ago) it is fueling up really slow. It takes about 20 mins to put 13 gallons of gas in. I have to just barely squeeze the handle to keep from the gas spurting back out. Its so slow that you can count the cents as it adds up. If i don’t hold it really slow the gas comes spewing back out the neck of the gas tank, or just bubbles back out and shuts the pump off. I thought it could be that my evap canister was plugged or the lines running from the gas tank to it, so i brought it in and they blew out all the lines with an air compressor and they said it was all clear. Its getting really frustrating standing out there at the pump for 20 mins. Any ideas? I really want to get this fixed before the COLD of MN winters comes!!! Please respond with any ideas!!!

Use the search button “slow fueling” there are about 7 pages of discussions that have covered this.

Also search for terms like “pump shuts off”.

Yup. It’s an evaporative emissions system (EVAP system) problem, a failure to vent the tank during filling. There are a few valves in the system that allow the air in the tank to pass through charcoal filter bed to capture hydrocarbon molecules and allow the purged air to vent right up by the fill hole, where it’s subject to being drawn back into the tank.

Question: do you “top off” your gas tank? If you do, your charcoal bed might be saturated, preventing the vapors from being vented.

Also, you may want to have the ECU scanned for stored fault codes. It monitors the EVAP system and might give you a hint at what’s wrong.

the same mountainbike: I do “top off” my tank sometimes, mainly cuz i never know if its actually full or if it just shut the pump off cuz of vapors. I normally just watch to see how many gallons i put in, and then stop when i know that its almost full. Would “topping off” cause the EVAP canister to not work properly? I have had it scanned a few times and it always says “no codes”

In some vehicles “topping off” the tank can allow liquid fuel to get into the charcoal canister, saturating the charcoal bed. Since the tank needs to breath out through the charcoal bed when you fill it, and since your tank cannot breath freely through a saturated charcoal bed, than yes, this absolutely could be the root cause of your problem.

In your case, the charcoal bed could be saturated to the point wherein large volumes of air such as is necessary to purge the tank’s air when you fill the tank are prevented from moving through the bed, but enough may be able to pass to allow it to breath in slowly as necessary as the gas is burned, so you may not have a stored code. Remember that the car’s tests are designed to ensure that no hydrocarbons are released into the air, NOT designed to test whether the tank is having difficulty purging air in the high volumes necessary during fill up. It doesn’t test what happens during fill up. It only checks after, when the engine is again turned on, to be sure no fumes can leak out.

Note that you’ll probably also have a diaphragmatic valve that opens under pressure when the tank is filled to direct the fumes through the canister in volume, as well as a float mechanism to shut that valve, the pressure buildup then being sensed by the pump handle. I don’t have access to your specific system, but that’s the way they typically are set up. It is that former system through that “topping off” can allow liquid fuel to the charcoal bed.

I wish I knew some simple way to test charcoal canisters. But I don’t. If anyone else there knows a valid technical way of testing the canister without removing it, I openly solicit your assistance.

I would suspect the Vapor Control Valve.

The basic elements forming the ORVR system (Figure 101), (Figure 102) and (Figure 103) operation are as follows when fuel is dispensed:

1.The fuel filler pipe forms a seal to prevent vapors from escaping the fuel tank, while liquid is entering the fuel tank (liquid in the one inch diameter tube blocks vapors from rushing back up the fuel filler pipe).
2.A fuel vapor control valve controls the flow of vapors out of the fuel tank (valve closes when liquid level reaches a height associated with the fuel tank usable capacity). This valve accomplishes the following:
a.Limits the total amount of fuel that can be dispensed into the fuel tank.
b.Prevents liquid gasoline from exiting the fuel tank when submerged (and also when tipped well beyond a horizontal plane as part of the vehicle roll-over protection in road accidents).
c.Minimizes vapor flow resistance during anticipated refueling conditions.
3.Fuel vapor tubing connects the fuel vapor control valve to the EVAP canister. This routes the fuel tank vapors (displaced by the incoming liquid) to the EVAP canister.
4.A check valve in the bottom of the fuel filler pipe prevents liquid from rushing back up the fuel filler pipe during the liquid flow variations associated with the filler nozzle shut-off.
Between refueling events, the EVAP canister is purged with fresh air so that it may be used again to store vapors accumulated engine soaks or subsequent refueling events. The vapors drawn off of the carbon in the EVAP canister are consumed in the engine.

Ok so thank you for all the responses! That diagram is very helpful, i looked for a diagram like that for hours last week and couldnt find it. I know how the evap system works. My real question is: is there anything i can do at home, without bringing it in to the shop and having them drop the tank, figure out whats wrong, fix the problem, and charge me $500???

It looks like it’s one unit mounted under the car.

knfenimore: is that what the evap canister looks like?

That is the where the Fuel Vapor Control valve is.

ok is that visible from underneath without taking off a whole bunch of parts?