2003 Mustang Gt won't start.

[Tko2v]

I have 2 different cut and programmed keys that i've used and still no luck. When the intake was off, the battery was out for days. I just checked the THEFT light, it stays on briefly then cuts out.

[juiceweezl]

I have 2 different cut and programmed keys that i've used and still no luck. When the intake was off, the battery was out for days. I just checked the THEFT light, it stays on briefly then cuts out.

If the theft light comes on briefly when you turn the key on and then goes out, it's functioning properly. It would flash rapidly if the anti-theft were on.

[Tko2v]

Ok well theres something to knock off the list.

[crapstang]

teabag it

[juiceweezl]

Did you check fuel pressure at the rail? You can use a schrader valve to check it.

[Tko2v]

I haven't checked the fuel pressure yet, but I have teabagged it numerous times, which in turn led to no help.

[taylor-swift]

What's Problem

[Tko2v]

Sorry for needing the constant help, but how exactly would I check my fuel pressure?

[shumpertdavid]

SEE POST 22, buy a "fuel injection" fuel pressure gauge from the parts store. There will be a test port, schrader valve, on the fuel rail. Screw gauge to port, crank car, check gauge. Fuel Pressure spec is 35-70 psi on that car. Should probably be 35-45 psi cranking it over. If you'll follow the steps in my post it will help you and save a bunch of posts and random answers. You need spark, fuel pressure, and injector pulse. Check those and report back with findings.

[JC316]

Ok, for sure it's not the anti theft as it will allow the car to start for at least 1 second. Go back over the intake and make sure that nothing was left disconnected. Check all of the fuses, especially the one for the injectors. Make sure that the camshaft position sensor is still plugged in, it goes into the front cover, under the power steering reservoir. Get a fuel pressure gauge and check the fuel pressure.

[Tko2v]

ok good and bad news. Good: I have replaced the fuel pump and a friend brought over an obd2 reader and we checked it but no codes were thrown. Bad: still won't start, it's doing the exact same thing.

[Tko2v]

I haven't checked the fuel pressure yet, that's the next thing on my list to do.

[krazy kris]

spray some starting fluid in the intake and when you go to start it push the gas pedal about halfway down

[Dinger]

Thats exactly how mine acted .. still not 100% on the diagnoses but My fuel pump was not coming on when I turned the key..

Do you hear your fuel pump start when you turn the key?

[LS1Goat]

It could be a PATS issue with the theft light. Try using your 2nd factory key.

My PATS steering column transceiver took a shit in my '00 Mustang one time. It turned over and over all day, but wouldn't fire up. I put a fuel pressure gauge on the schrader valve. I was suspecting a fuel pump failure. And sure enough it was reading about 11 PSI at the fuel rail key on/engine off. However, I immediately followed it up by doing a code scan and there it was. P1260 DTC, which is a PATS code related to the Key/Transceiver/Bus link to the instrument cluster. I just had SCT disable PATS in the tune file and email me the updated file. Loaded it in the tuner and reflashed the car. Fuel rail pressure jumped back up to normal and it fired right up.