Slow re-fueling 2000 GT

wmburns

SN Certified Technician
Aug 14, 2009
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Houston Texas
I have completed the Windsor to Romeo engine swap in my 2000 Mustang GT. Went to fill up. The service station pump shuts off after a small amount of gas flows (like it is full). I tried every way I could think of to adjust the nozzle (up, down, left, right) no luck. It takes a very long time to re-fuel because of the constant shutting off. I tried at 3 other gas stations with the same result.

The car did set un-drivable with a full tank for two years before I bought it. The tank was drained and refilled before putting in a new engine (forced ran the fuel pump).

A visual inspection does not show any obvious problems. The car drives perfectly. No DTC’s codes even after several hundred miles of driving.

I am attempting to research the problem and not really getting a good picture of how everything is connected on top of the gas tank. One of the things considered was a stuck filler check valve. I tried poking it with a stiff hose. I can feel it move and it does help for a fill up but then goes back to slow filling.

Not thrilled about pulling the tank. Unfortunately, Ford does not sell the check valve by itself (only the complete filler tube assembly for $117). Further, if I am going to pull the tank, I want to be sure to check for all possible problems it could be while the tank is down.

If anybody has any ideas, I would love to hear them. Thanks.

OBTW, which Vapor Management system does the 1999-2004 Mustang use (enhanced)? How does the Mustang actually vent air during re-fueling?
 
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I have completed the Windsor to Romeo engine swap in my 2000 Mustang GT. Went to fill up. The service station pump shuts off after a small amount of gas flows (like it is full). I tried every way I could think of to adjust the nozzle (up, down, left, right) no luck. It takes a very long time to re-fuel because of the constant shutting off. I tried at 3 other gas stations with the same result.

The car did set un-drivable with a full tank for two years before I bought it. The tank was drained and refilled before putting in a new engine (forced ran the fuel pump).

A visual inspection does not show any obvious problems. The car drives perfectly. No DTC’s codes even after several hundred miles of driving.

I am attempting to research the problem and not really getting a good picture of how everything is connected on top of the gas tank. One of the things considered was a stuck filler check valve. I tried poking it with a stiff hose. I can feel it move and it does help for a fill up but then goes back to slow filling.

Not thrilled about pulling the tank. Unfortunately, Ford does not sell the check valve by itself (only the complete filler tube assembly for $117). Further, if I am going to pull the tank, I want to be sure to check for all possible problems it could be while the tank is down.

If anybody has any ideas, I would love to hear them. Thanks.

OBTW, which Vapor Management system does the 1999-2004 Mustang use (enhanced)? How does the Mustang actually vent air during re-fueling?

most of the time when you get a problem like yours it's due to cobwebs or other debris in the evap lines. you can blow the evap lines out
 
I have completed the Windsor to Romeo engine swap in my 2000 Mustang GT. Went to fill up. The service station pump shuts off after a small amount of gas flows (like it is full). I tried every way I could think of to adjust the nozzle (up, down, left, right) no luck. It takes a very long time to re-fuel because of the constant shutting off. I tried at 3 other gas stations with the same result.

The car did set un-drivable with a full tank for two years before I bought it. The tank was drained and refilled before putting in a new engine (forced ran the fuel pump).

A visual inspection does not show any obvious problems. The car drives perfectly. No DTC’s codes even after several hundred miles of driving.

I am attempting to research the problem and not really getting a good picture of how everything is connected on top of the gas tank. One of the things considered was a stuck filler check valve. I tried poking it with a stiff hose. I can feel it move and it does help for a fill up but then goes back to slow filling.

Not thrilled about pulling the tank. Unfortunately, Ford does not sell the check valve by itself (only the complete filler tube assembly for $117). Further, if I am going to pull the tank, I want to be sure to check for all possible problems it could be while the tank is down.

If anybody has any ideas, I would love to hear them. Thanks.

OBTW, which Vapor Management system does the 1999-2004 Mustang use (enhanced)? How does the Mustang actually vent air during re-fueling?

Yep Yep I had this issue before when I had my SLP exhaust Dump right over my rear axel. Its possible if you are running dumps or if you exhaust, is just hot you could have melted your evap lines or just have something in them. They are easy to replace, when I had done mine I went to AutoZone and got about 6ft of Good Year 7/8 inch high temp heater hose and ran them the length of my old melted ones. If you ever seen the Vacuum line coming of the driver side vale cover of a stock GT its made from the same plastic piping. Just run them the length of the old ones from the charcoal canister to you filler pipe and to your tank and the over flow. It’s a 5 dollar fix.

Crawl under the rear of your car and take a look at the evap hoses that run from your filler/pipe around the front of your tank and to the left side to the charcoal canister. They are pretty easy to spot.

At first I thought someone put a Ping-Pong ball in my tank, then thought it was the anti siphon filter. Then climbed under and found a heap of melted plastic hoses. Even though you are slicing through the air the negative air space in the wheel well and other cavities of mustangs do not vent well so they collect a lot of heat in different areas especially underneath the car.

Heater hose.
http://www.goodyearep.com/uploadedI...om/Image_Gallery/Aftermarket_Parts/ezcoil.jpg

this like has a few pics to look for on the evap lines, but its for a fule pump replacement. Image 13 shows the evap hoses.

Google Image Result for http://www.troublecodes.net/articles/evap2.jpg
 
Possible bad charcoal canister?

Update on the slow re-fueling problem. I have confirmed the canister purge valve is open and free flowing (also confirmed closes when voltage applied). Also confirmed that all vents and hoses are free flowing. The fuel filler neck (including check valve) is new as well as the gas tank grommet.

The charcoal canister itself is very difficult to blow through. I suspect this is preventing air/vapors from venting during re-fueling. However, I wanted to get some other thoughts.

How hard should it be to blow through the charcoal canister? Are there any tests for the charcoal canister? Is there anyway to unblock it?

I was taught that charcoal canisters do not go bad unless raw gas gets inside. Could two years of storage cause the canister to go bad?
 
http://ww2.justanswer.com/uploads/muddyford/2009-09-02_045304_1121.pdf I don't know how much this helps, I found it interesting though.:shrug: From doing some reading on the Charcoal canister, I think the canister needs fresh air going through it from time to time for the canister to function properly, I think you found your problem, here is the add I read from a F-150 forum.
The charcoal canister is a vital portion of the Evaporative emissions system.

Other portions of the Evaprotive emissions system besides the canister are...

1: Evaporative emissions Fuel Caps
2: Canister Purge Valve, or solenoid.
3: and to a small extent, PCV valve.

It's basicly a closed venting system for the tanks and carb bowl vent.

As was said previously, fuel vapor from evaporation is trapped in the canister when the engine is off.

When the engine is running, during the purge cycle, the fuel vapor is purged from the canister and burned in the engine. The purge portion of the system consists of a canister purge valve, or solenoid, and utilizes the small port on the PCV valve.

When fuel is consumed from the tanks, fresh air enters the system, through the bottom of the charcoal canister, venting the tanks. The Activated charcoal in the canister acts as a filter. Alows fresh air to enter the system for venting, but traps fuel vapor inside the canister from escaping to the atmosphere.

Benefits of the system...

1: Your truck wont smell of gasoline on hot days parked in the sun.
2: Helps to keep fuel in your tank from evaporating.

It's one of the smog components I recommend keeping, as there is no side effects from leaving it on the truck.

Also there are unforseen side effects from disconnecting it improperly. You can have vapor lock, the tanks wont vent properly, fuel odor smells, fuel erupting from the fuel filler from pressure, etc...
 
I must be in bizarro world, where trombone gives wmburns advice :crazy:

A lot of times the slow fill is related to ripped gas filler neck just inside of the cap.
I thought the problem was a sticky check valve in the filler neck. So I installed a brand new filler neck and tank grommet. $200 in parts later and it still takes 20-30 minutes to fill up.

I am absolutely positive all of the vent lines are clear (tank dropped all lines confirmed clear). The CV purge solenoid has been functionally tested OK. However, it is very difficult to blow through the canister itself.

No DTC codes. Car drives great. Until it gets to the gas station (bring a good book. Oh scratch that. One hand needed to operate the pump).

I haven't the faintest idea how to tell if canister is clogged up. Nor do I know what "normal" is. It seams reasonable to me that a clogged canister could cause my problem. After replacing a perfectly good filler neck, I really don't want to throw more parts at this problem if I can help it.

Thanks so much.
 
I must be in bizarro world, where trombone gives wmburns advice :crazy:

A lot of times the slow fill is related to ripped gas filler neck just inside of the cap.

What the! Hey, hey, hey......:rlaugh::D I'm learning from his misfortune, He's smart as muther, isn't he:nice::hail2:Both of ya's.
How does the pump know when to stop pumping gas? Is it the fumes or the gas itself, if its the fumes, then I'm thinking yea, the canister is the problem if you gas tank is not venting properly, if there was no air going through your canister from all of those years then the components of the can became saturated, thus not functioning properly. Just a theory.
 
The Fix for slow filling

Update on the slow fill. Apparently in 2001 Ford changed the design of the gas tank. The filler neck vent line was moved from the side of the tank to a "tee" fitting on top of the tank.

I was surprised to learn there is a 3/32" restrictor orifice in the vent line. Why it is there I do not know. I drilled the hole out two sizes to 1/8".

The results! For the 1st time in a long time, the tank accepted a full load without shuting off until the tank was actually full!

The vent line is easy to access and does not require the tank to be dropped.

I suspect that others have this problem and this is the reason Ford modified the vent after 2000 MY.

Thanks everyone for your input.
 
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There are two hoses connected to the filler neck. The larger slip fit is the canister vent.

The smaller hose with a connector that looks like a old style fuel filter clip is the tank vent. The orifice is inside the connector on the end of the hose. It can be easily seen/accessed from below.

Disconnect the vent hose from the filler neck. The orifice is visible at the end of the hose. Simply drill it out. I used a 1/8" drill which increased the hole by two drill sizes.

I suspect the orifice is there to limit the amount of gas/venting should the car be in an accident. Hence the reason I didn't drill out all the way.
 
Thanks for the PM!

Do you have any pics of which line it is?

Good to hear that you fixed the problem.

Thanks! :nice:
no sorry.

There are only two lines (in addition to the filler line itself). There is an obvious size difference between the lines. Again, the large line is the canister vent. The smaller line is the tank vent (the magic vent).

If you absolutly can't figure it out by yourself, will go from there. The fix is almost stupid easy to do.
 
Update on slow re-fueling 2000

Quick update. Drilling out the vent line fixed slow re-filling problem about 95% of the time.

I am positive that the true fix is to replace the charcoal canister. Mine can not be blown through even with high pressure compressed air. It is an $80 part new from Ford.

The work around has improved the situation to the point it is manageable. Perhaps I will fix it for good when the weather gets cooler (hot in Texas).

Thanks again everyone for the input! :nice:
 
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You don't need to thank anyone! You help everyone on this forum enough. Actually, my '99 has an occasional issue like this, so once the Tampa area cools down, I'm doing this and (eventually) replacing the charcoal canister as well!

Thank you wmburns!!
 
I know this thread is very old but I came here to seek an answer to my refueling problem as well. With the off chance that someone would do the same, I have found my solution. I would re fuel and never could get past a couple of dollars on the highest setting and even on the lowest trickle I could hold it would still shut off. I saw a used charcoal canister on eBay and decided to take the $16 chance and BOOM! $16 and 20 min of my time and the fueling problem is completely solved
 
Update. Replaced the charcoal canister for the final fix. At this point in time I have had several years of trouble free operation.

Bottom line. For slow re-fueling think first of a block in the gas tank vapor lines. First place to look is the CV Vent solenoid as spiders and other insects like to build their homes there. If the CV Vent solenoid is good, then think clogged charcoal canister. NOTE: you should be able to blow through a good working charcoal canister. So in my case the fact I could not meant a bad canister and hence WHY the gas tank was not venting correctly during re-fueling.