DoctorQ

About 4 weeks ago I posted a poll regarding the fuel fill issue. I wanted to share those results (which I took to my meeting with Ford) with this forum along with events from the meeting. The poll question asked if forum members have experienced the premature fuel nozzle shut-off while attempting to fill their tanks (usually shutting off after ½ tank). I posted the poll on 3 separate S197 Mustang Forums with the following results:

224 Total Responses:
20% (44) responded that they ALWAYS encounter the fuel fill issue.
51% (115) responded that they have encountered the issue, but not all the time.
29% (65) responded that they have NEVER encountered the fuel fill issue.

Now, I know this poll may not subscribe to accepted scientific study standards, however, most of data was collected within days of the posted poll. IMO, this is a surprisingly high percentage (71%) of S197 owners who have experienced this fuel fill issue (either all the time, some of the time, or resort to flipping/inverting nozzle in order to fill their tanks).

Background: I have an 06GT (18 months since I drove off the lot). For the 1st year, I would encounter the fill issue about every 3rd or 4th fill-up… stopped at half-tank each time. I tried all the tricks to re-engage the fill (turning nozzle.. inverting nozzle…), no dice. No additional fuel could be added. During the past 6 months, the problem began to escalate to just about every fill-up. Finally decided I’ve had enough and scheduled my first fuel-fill warranty service trip. Ford found that the EVAP Canister was slightly obstructed causing excessive tank pressure build-up as the tank was being filled. They did this by monitoring the FTP (Fuel Tank Pressure) sensor. Sensor voltage started out at 2.6v, then reached 3.5v at ½ tank. As was explained to me, any voltage above 3.5v is too high, meaning excessive tank pressure is being experienced. Fuel system interpret this as tank is full (no room left for fluid), and causing pump to shut off. This voltage should never exceed 3.2 – 3.3v. Ford replaced my entire EVAP Canister assembly tray (EVAP canister, canister vent solenoid, EVAP filter), cleaned all the lines, checked purge-valve, tank check-valve, and tank pressure…all was good. Within 3 weeks, issue came back; however, after the ½ tank fill stop, I was now able to invert the nozzle to 2-o-clock position, and continue to fill tank completely. So I contacted Ford dealership and they arranged for a Ford Rep to come out. I was instructed to return to the dealership with less than ¼ tank. Upon arrival, the Ford Rep was a no-show, but he left instructions with the Service Manager insisting we take my car to a station of his choice, as he claimed the issue is with certain stations (fuel flow rates) and nozzle design. I refused and shared with them that I bought this vehicle in good faith assuming I could get gas anywhere of my choosing… dealership lead tech agreed, so we piled in my S197 and headed to my local fueling station. Ford’s Drivability Lead Tech hooked up his laptop to the OBD port then instructed me to open tank cap and begin filling. I was also instructed to lock the pump on the lowest speed auto fill and do not touch it (i.e., “step away from the nozzle”). He monitored the FTP sensor voltage as the tank filled. Sensor started out at 2.6v.. .then slowly climbed to 3.1v, but no higher (due to the new EVAP canister assembly). CLICK… tank shuts off @ ½ tank. This was actually good news as it indicated that excessive pressure was not to blame (as it was before) for the premature nozzle shutoff… but something else. I then challenged him to attempt to fill tank completely. He tried, several times, unsuccessfully. I then showed them by inverting nozzle to 2 o clock position I could continue to fill up… and fortunately this worked… the remaining 7.5 gallons (right side saddle tank). Ford’s Drivability Lead Tech stated this proved it is NOT just an EVAP emissions pressure issue, but also a filler neck design issue. He shared with me that the Ford Rep had previously shared with him that Ford was aware of the S197 tank design flaw, and they have encountered this fuel fill issue numerous times. Midpoint mounted saddle tanks… in a lower-profile vehicle… with all the required EVAP emissions systems, just don’t play well together (late model Corvettes have this same issue). Many things must come together in order to fill our tanks completely: (1) proper filler neck angle (more on this below); (2) pristine EVAP emissions system; (3) slow fuel fill rate. When excessive tank pressure builds, station nozzles will shut off. The S197 has multiple points causing back pressure: tank inlet check valve, saddle tank design and improper venting, inlet filler neck hose size and inlet hose angle, EVAP emissions system (EVAP canister, canister vent solenoid, EVAP filter, canister purge valve, FTP sensor, etc, etc).

So here is what they did: We returned to the dealership, put my rig up on the lift, and the Ford Drivability Lead Tech showed me the inlet hose issue. This hose attaches directly to tank inlet, and in most cases, is a bit too long and improperly angled. He disconnected this inlet hose and cut off approximately 3/8 of an inch (depending on each car, this can vary). He cut off enough to angle the tube directly down to the tank inlet flange. Shortening the hose also required lowering the hose support bracket. Lowering the hose support bracket required adding a spacer between bracket and body. This spacer allowed the bracket to drop down another ½ inch helping the overall inlet angle to tank. See pictures below. Next 2 fill-ups (at the same station, same pump where I ran into the fill issue) no stoppage! Tank filled to full each time without stopping. On the record, Ford said this issue is caused by the variability of each station’s pump pressure and nozzle design.

Off the record, Ford admitted the issue is caused by the inherit S197 tank design flaw. They also said they are aware of the issue and designed a fix about a year ago; however, this fix involved re-routing the inlet hose through the trunk and strait down to the tank. Two problems with this fix: (1) too costly for Ford to retrofit all the problem S197s on the road; (2) safety concerns with routing fuel into trunk area. Bottom-line: Ford abandoned this fix.

Now, why don’t all S197s have this issue? It appears that for issue to surface, (1) vehicle’s EVAP emissions system has a slight obstruction (either due to dirt or kinked evap hoses), AND/OR (2) fuel inlet hose is improperly angled and slightly too long (causing a slight upward rise in hose immediately before attaching to tank), AND/OR (3) fuel fill rate is too fast and/or filling station tank pressure too high. So, if you’ve never encountered this issue, feel fortunate all the “saddle-tank filling stars” are all aligned in your favor. However, keep in mind over time, your EVAP emission system will begin to become dirty, and that may be just enough to tip the scales to the ½” fill syndrome down the road.

Sorry for the lengthy post, but I wanted to provide feedback to possibly help those still plagued with the fuel fill issue. For some, cleaning (or replacing) the EVAP canister/ emissions system is enough to allow full tank fill. For others (like me), it took both the replacement of the EVAP canister assembly and re-angling of the fuel filler neck. Will this permanently solve my problem? Time will tell. As for now, it works. Good luck and hope this helps those still in need. Here are the links to my other tank fill threads:

http://forums.bradbarnett.net/showthread.php?t=466274

http://forums.bradbarnett.net/showthread.php?t=465217

USMC0341

Thanks for the write up, thats great info

05GT-O.C.D.

That's all great, but they know of the problem, they're not stupid, heck they've got a class action lawsuit out of California over the issue. The problem should've been fixed in 05-06, and shouldn't be continuing in 07, etc with the issue not clearly solved. That is unacceptable for a gasoline powered car to have problems being filled up with gasoline and FoMoCo to only band-aid the issue when it surfaces instead of curing the issue so that new cars going down the production line don't have the same problem.

Glad it's solved (for now). And to give you some hope, after I figured my problem being w/ the evap system and disassembling / cleaning it out, I still haven't had any problems. Fortunately, between the new tank and my evap clean-out, my problems appear solved. :fingerscrossedandknocksonwood:

DoctorQ

John... I couldn't agree more. I refuse to accept the fact I'm supposed to seek out low-pressure fueling stations or stations with certain types of nozzles. As I told Ford, I bought my car in good faith assuming I could fuel anywhere of my choice. My Dealership has been exceptionally good about trying to fix it.. but their hands are tied as they get their marching orders from Ford. A complete redesign is the only way to truly solve this issue.

Burke0011

Wow - THANKS for getting this info out there and being so detailed

MUCH appreciated!!!!

frdtch05gt

Wow, excellent info. My '06 has been really good, it fills every time. I am saving this information for future reference though. Thank you for writing this all out, it will help a lot of people here fix this issue.

wjones14

Thanks for the info DoctorQ! I always wondered what the technical explanation was.

For the record, which I have stated many times, my '05 has had the fuel filling issue since Day #1. I have always been reluctant to bring it in and do something about it, however, until there is a proven 100% fix. As a workaround, I simply insert the nozzle normally, then pull it back an inch or so. This works every time, and I have been doing this now for almost 30K miles.

Mustang_Ed

DoctorQ, thank you for your excellent write up.

We have never had a fuel fill issue with our 2007 GT Convertible. However, I am saving your descriptive and detailed post in case we ever do have a problem.

metroplex

A guy at work with a 08 GT said his fills up fine only at BP stations but refuses to fill up at any other station.

My Blue Heaven

I've had the issue since day 1 also, but luckily I have two stations in my neighborhood where I can get 2 pumps to work (at each) I found that if I'm parked on a slant with the front of the car on the downslope rear of the car up and use the slowest setting it works everytime. A couple of years ago let my gas get too low and had to get gas at another station not remembering the fuel problem and I think I was finally able to get a couple of gallons in before I gave up. That was enough to get me to my neighborhood station.

I really hope they recall this issue soon.

Pwny

Bumping thread.

I just started encountering this problem.

woody24

Oh wow. I've kinda forgot about this problem. I always figured it was an issue with each station. For me it would always do this at Shell Stations. I guess I've only been stopping at stations that I haven't encountered this problem with from then on, and guess I kinda forgot why I only used those stations. lol.

But I know I was getting frustrated before. I remember the first time, I was only able to put about $2.50 in my car before I got frustrated and left. And that was put on my credit card.

05GT-O.C.D.

I had the problem and fixed it by doing the following.

1) Make sure you have the 'redesigned' tank. I think most, if not all, 06's have the redesigned tank, but I don't remember.

2) Take apart and blow air through all of the evap/emissions equipment on the right side of the tank to clear any obstruction (Cob web, condensation, etc)

Reassemble and cross your fingers. Worked for me and I've been problem free since.

69Mach1-409

Thanks for the info!

=knock on wood= I don't have this problem, but as you said.. it could start at anytime.

metroplex

There's a fresh air intake tube for the evap system that generally gets clogged with stuff like spider egg sacs. I ran into a problem with our 03 E-250 that was caused by the spider eggs.

I used compressed air and wire to clean out the tube (it is a hard plastic tube, similar to what Ford uses for a lot of its evaporative emission connections) and wrapped the open end with aluminum mesh and secured it with a hose clamp. Make sure not to cut yourself with the mesh.

When filling up the gas tank, turn the nozzle counter-clockwise a few degrees (with the gun almost at the 3'o clock position) and begin filling. Lock the trigger in place and gently release. It should drop down to only a few degrees CCW from a straight 6'o clock position. It's very temperamental and I'm surprised it isn't an Italian car.

CW_06_GT

I have a 06 GT but I have never had "that" problem filling my tank. My problem is that it "over" fills my tank. Every time I fill up the tank and lock the gas handle on, the pump cuts off too late and I always get a small amount of gas that comes out of the filler and I've been lucky that the black plastic over flow area has been able to keep the gas from getting on to my paint.

woody24

Ive had this problem as well. Only mine was much worse. It only seems to happen when it shuts off half way. When it shuts off half way, and I finally get it going again, i have to just listen to it. Because the first time it happened, it just kept running, and I didn't know it until I felt splatter on my feet. It had over-flowed, and was running under the wheel well. It didn't shut off until I manually grabbed it.

Probably dumped about $5 of gas on the ground. I wasn't too happy.

Pwny

I think I will just take it into a dealership under warranty.

adrenalin

Thanks for the great write up. I had the same fill problem when I first got my car. FORD replaced the tank and so far I have not had a problem since. Most likely the intake hose was not connected the same way on the new tank.

RRRoamer

I started having that problem after about 6 months on my 05. When the TSB came out, I took it in and had them replace the tank. That was over two years ago and I haven't had a single issue since.

It usually fills up to the point that I can't even "squeeze in" another 1/10 of a gallon after it clicks off. I don't even try anymore.