Mustang GT problems
 

Ok so, I recently bought a 2003 mustang GT and know the car is acting up, when I try to crank it, it will turn on but cut right off, this happens around 3 times then it's fine, it feels like lts running a little rough and is lacking power. I just replaced my camshaft position sensor And crankshaft position sensor and it didn't help. Any idea what this could be?

Helpppppp!

Did you replace the Coil Packs / Wires / Plugs? I had a 95 Linconl Mark VIII with the 4.6 and the packs started going bad at about 120K and I had to replace the plugs often. I replaced the coil packs at 140K and she ran fine all the way until 225K when I traded her in.

You can also try checking out your MAF sensor too

Check fuel pressure. Could be fuel pump or most likely the fuel filter. People always overlook the fuel filter

What is the MAF? And what are symptoms?

When you had your Lincoln what did it do? How much did everything cost?

Would the fuel pump cause the car to shut off tho?

Your going to have to plug her in and see what if any codes are thrown, any auto parts store will have one and they will tell you whats going on....

I did, I went earlier in the week and it said camshaft position sensor, so I replaced that and the crank shaft position sensor, but the car still has the same issues, the light comes back on with the same error code "camshaft position sensor" I'm lost and don't know what else to do!

Well Crap, do you think that one was bad? No other codes... Man I hate throwing parts at problems..

Yeah man it sucks! I wouldn't think so but who knows! There could be a chance! I hope it's something simple.

Not sure if your car has a distributor cap, but you might want to check that.

Mine does the exact same thing.

Try to crank it up next time, but pause in the on position (right before cranking), in that spot, it activates the fuel pump and builds some pressure. Mine starts doing that.

Try cleaning your Mass Air Flow sensor and Throttle Body (both very easy, get the right stuff, and search on how to do it).

I haven't nailed it down myself, but I believe it's the fuel pump starting to go.

Costs
 

Everything was under $200 for sure - maybe as low as $150.

If you think it's fuel pump, take the intake off that goes to your throttle body and while someone cranks up the car spray carb and choke cleaner in the throttle body if the car runs without shutting off then you most likely have a fuel problem. You're in a really tough position trying to diag this without an IDS from a ford dealership because there are alot of possibilities, it could even be your iac sticking when you start the car. I do agree you have either a fuel or air problem you're just going to need to mess around a bit to pin point the cause.

Seen this before. If you haven't figured it out yet.
The hose attached to the fuel pump in the tank can get a small hole in it letting the fuel drain back after you kill it. Making the next start up difficult. I would check the hose.