spierce2112

Hello,

For the past few months I have had an issue that sometimes occurs after filling my tank. After filling up, I reach a red light and my truck will hiccup or kinda bog for a second while stopped and at idle. I have documented the last 3 fill ups and it did this 1 - 2 times at each light for about 2 - 3 lights/the first 3 miles or so. After about 3 - 8 minutes it stopped doing it.

I have also noticed it randomly hiccups like this when the truck is warm, it's hot outside and a/c is running. It's done this since I bought it new.

I have read about overfilling issues but I don't think I am doing that. I let the pump click off on its own and don't add fuel after it does. I have done that since day 1.

Unfortunately there are no codes. However, I did have it serviced about a year ago for code P2450 - Evap Blocking Valve which was replaced under warranty... not sure if that relates to this issue.

I have approx. 33,600 miles on it so I concerned that my bumper to bumper warranty is going to be out soon before a code pops up.

Has anybody here had this problem and if so what was the outcome?

Would like to get some feedback before taking it to the dealer...

Thanks,

Shawn

dodgeman1

Most likely emissions related but tough to say exactly what. I'd say its related to the evap system though. If it were me I'd put a new gas cap on just because they are cheap but I doubt that's the problem.

Ohsix

Madcap57

I am still laughing about this. There is no gas cap.

Aj06bolt12r

My truck has done this since it was new. It always has a bit of a rough idle that comes and goes. No codes. I've replace the spark plugs and set the correct gap twice. I've cleaned all of the maf and map sensors. It has never gotten any better or any worse. I've decided to simply live with it unless or until it gets worse or throws a code. I don't believe that its hurting anything. 51,000 miles. 2015 3.5 eco

Jonm1911

I have the same thing, but I haven't noticed if its after fillups, seems to be hit or miss, whwnever it feels like doing it. My buddy's 2010 did it.

dodgeman1

Well no wonder it runs bad, rainwater is probably getting in the tank with no cap. Totally forgot the no gas cap thing and I own two vehicles that don't have one. I wonder if the sealing system where the gas cap goes ever goes bad?

spierce2112

For some time I have wondered if maybe it was a plug issue maybe set off by the direct injection technology. Or possibly there is a slight air/fuel mix ratio imbalance that is affecting the engine at idle when this happens to mine. IDK... It isn't all the time but it does happen enough to make me think about it. Maybe it has something to do with the humidity and the outdoor air temp which are both high here in south Florida.

As far as the fueling issue goes... I think it is an introduction of excess air. I noticed the pump handle never seats flush against the filler spout. Gonna pull over immediately after next fill up, cut the engine and wait a good 10 minutes before driving. Curious to see if the problem will exist or not.

Aj06bolt12r

I have just about convinced myself that is a combination of direct injection and emissions regulations. I don't think direct injection is at its best at low load, engine idle situations. Also I think that they run the engine extremely rich at idle during warm up to get the catalytic converters up to temp, then they ruin the engine extremely lean at idle to improve emissions. I think those strategies combined with direct injection add up to the odd misfire at idle. I wonder if the newer engines with port and direct injection have this issue. I would almost bet that they don't.

I also think Ford is aware of the issue and that they have widened the misfire parameters that would trigger a check engine light to keep the light from coming on. That is the only way I can explain the lack of a check engine light for a misfire. Because you can for sure feel a misfire. Again I don't believe it's hurting anything.

These are only wild speculations from my own feeble mind... No idea if the previous statements are true or not.

dodgeman1

As a rule you are correct, when cold the computer does not really change the air fuel ratio like it does when thing are warm, so they tend to run rich since there is no choke like there was on a carb. I think you are also correct, they want to get every thing up to temp to meet emissions as soon as possible.