Ok well I got everything installed fine, I started the car and it runs great. But the fuel gauge is messed up!! On my way home from JDM I was on a little under a quarter (38 miles to empty) so I stopped at a station to fill up a little so I would make it home. I put $10 in and it put me between a quarter and half. Now when I start the car it is saying 40 miles to E and between empty and a quarter, but closer to empty!!!

Any ideas??? I tried the switching the wires in the fuel sender unit harness and it didnt change at all!!!

 

It happens when you de-pressurize your tank.
Take her out and drive around for a bit. It will slowly but surely make it's way towards full.

 

Alright thanks man, I am going to try it. Jim over at JDM said put a little bit more fuel in it, and drive around a bit and see what happens.

 

Same thing happened to me when I switched my fuel filter. ^-^.

I asked around about it, and no one really knew, so I'm just putting my money on the depressurization.

 

Nope that wasnt it, but we found the problem. I went to the station about 2 miles from my house and put $20 in (now this shouldve put me around 3/4 of a take from what I had in there already) and it actually went down. Spoke with Jim and turns out I have the wrong fuel pump in my car. I have a pump for the 05-09 stangs in there, and somehow the pumps got switched up, cause the part number on the box (for a 2010) doesnt match the part number on the pump (for 05-09). So all I have to do is take this pump out, head down to JDM first thing in the morning and he is going to give me the right pump.

 

Glad you got it all fixed!
Sucks that they put the wrong one in.
Tsk Tsk!

 

Yeah its a pain in the *** that I now have to take the pump out and put another one in, but at least we know what the problem is. Jim @ JDM helped me through anything and answered any questions I had and even found the problem by searching the part numbers for me. I HIGHLY recommend JDM to anyone looking to get something for your mustang. They not only sell the part, they KNOW the part and install everything they sell so they know how it should work. Fortunately I live only 30 mins away lol but I doubt they would leave anyone hanging!

I even called Ford Racing and the guy was a real D!CK!!!!!!!! He basically didnt want to be bothered and told me that the wiring doesnt matter and basically just had a pissy attitude with anything I said or asked.

 

Dare I ask how you feel about your tune? LOL

Grabber you are very lucky JDM is close by, they are a great asset to have available.

 

I haven't gotten the tune re-checked since the pumps werent working today, but Jim @ JDM was going to see if he can get me in on there dyno to check it. He said they were extremely busy this week because their guy who does the work was out sick, but I would play it by ear and see what happens. Hopefully they can get me in, cause I would much rather them check their tune than someone else. Atleast they know what to look for

 

Something similar happens to me. Filling up an empty tank will be 60 or more and one day while filling up from empty it stopes at 35$ and it wouldnt let me put more and the fuel gauge was stuck at the half way mark. And now in days it's been stuck at full it so annoying having it stuck ...