Car has been having some problems. Erratic, intermittent starting problems. May start fine on day 1 and not start day 2. Or it may start fine in the morning then sit for a while at work and not start.

Cranking and cranking. No start. Pulled off fuel pressure sensor then turned key to prime system, no pressure.

Changed fuel pump. Started right up. Drove it home 5 miles. Sat for 2 hours started up. Went to visit parents 4 miles away. Sat for 2.5-3 hours. Leave and won't start. Sprayed this starter stuff? Into the intake. Starts, runs for 5-10 seconds gurgles then dies. WTF. Also we changed fuel filter today. So. It has to be fuel related. No fuel to engine. Im guessing either fuse, micro relay, or fuel pressure sensor going out. Please please help

 

So I have a very similar problem one time it'll start right up, one time it'll turn 5+ times and others it won't start at all ill have to turn off and retry a few times, I've changed all ignition components, fuel filter cleaned intake - tb, injectors, everything but the damn pump.

Things I've noticed:
When I fill up is when it's the worst,
When it's been sitting for a while (day or so) it starts up fine,
When it's been sitting for A fewinutes it's intermittent (5-6 turn overs)
My af ratio isn't as steady as it was before I noticed the problem.. Sometimes cruising into the 13's and others into the 15's with no apparent change in lead foot syndrome..

I know this is t a solution but perhaps collective minds..

 

I've had a similar starting issue, but it would only not start when it sat out in the cold weather... under 30 to 40 degrees. Had to try 2-3 times.
When it's warm outside, in the spring and summer, never once had the starting issue.

I still don't know why

 

I'm thinking mine is either the relay, fuel pressure sensor or idk wha

 

damn electric issues..

did you try pushing the little "fuel pump reset" button down near your left foot (on the left wall)?

if you can't find it, look in the owner's manual..

 

I've pressed the reset switch after filling up and tried it then but still same not wanting to start.. I've also had my starter tested a few times just to make sure. I've read through the tsb's and couldn't find this exact problem.

 

Check the SJB (Smart Junction Box) behind the passenger kick panel for corrosion and water.

05 to early 07 had water intrusion issues in that area. If you got moisture back there it may be enough to corrode the connections but not enough to flood the floor pan.

With all of the weird issues you are having, I wouldn't be surprised if you found corrosion back there.

https://mustangforums.com/mustang-ts...LOOR-AREA.html

 

Have you checked your battery connections for corrosion?

 

Well here is some news. Switched the micro relay with a known functioning one. No luck. Relay is good. Went to old friend. Get some ideas then went to dealership for advice. They blamed tuner. But said possibly inertia switch or no electricity. Went back to car. Tested fuse box, there's power there. Check the plug that goes in top of fuel pump, there's power there. Dad put his hand on top of fuel pump, turned key 4-5 times. No vibration, no noise no anything. Dealership said possibly bad fuel pump. Called auto zone, they said ya, sounds like a bad new fuel pump. Just my luck. Got another one coming in tomorrow. See how that goes.

 

Yes. Cleaned battery posts yesterday