cpolanco0927

Hello everyone, Im new to this forum. I thank everyone for their help beforehand. Here is the situation:

My 2005 V6 4.0 Mustang died on the road on Monday. I had it checked by mechanic and said it was a bad alternator, battery was still good. Replaced the alternator and it started no problems, turned it off and back on about 3 times. No problem. Didnt run it, just on and off. Let it sit for like 30 min, turned on, pulled away from parking spot and one block down the street loss RPMs and died. Tried to turn back on and it will turn on some times, sometimes it wont. When it does, it will shake (rumble) lose RPMs and die. Any ideas? Thank you all for your help.

07 Stang

Hmm....I wonder if your car has been through a lot of rain recently? Maybe the Smart Junction box has gotten wet. Feel behind the carpet on the passengers side to see if you feel dampness. Unfortunately many of these cars have had issues with leaks causing havoc with the electrical systems.
I'm sure others will chime in with great suggestions.

mjbjr

Mine just did the same thing Friday on my way home checked and did all I have read here and it still won't start

cruisin5268d

Try checking your battery and key power cables under the hood. Perhaps something is loose. I'd start there as this checking is quick and easy.

jwog666

codes? could be related to alternator, or not at all

Nuke

I can't tell if you mean that it cranks and won't start or that cranking is intermittent. How many miles on the car and what maintenance has been done, such as plugs, fuel filter, fuel system cleaning, air filter, throttle body (TB) cleaning, etc.?

tradosaurus

First, find a different mechanic since it appears he is incompetent to diagnose this problem.
Second, I would troubleshoot the easiest potential problems. Others can chime in but I would start with the following:
1) Change fuel filter (if it hasn't been changed in 30,000 miles)
2) Check to make sure spark plug wires are are routed to the correct plugs.
3) Clean throttle body flapper valve with throttle body cleaner.
4) Make sure no electrical plugs in engine compartment are unplugged.
5) Check Air Filter and change if necessary
6) Check for vacuum leaks
7) Check to make sure ground wires that connect to engine or car body are clean. Also check battery terminals for cleanliness and make sure terminals are tight.


Have you recently ran your fuel tank dry to the point where your car wouldn't start? If so the fuel pump could be damaged.
Take of your fuel line at you fuel filter. Crank on the motor and see if gas comes out. If no, check power at the pump. if yes, then bad pump. If no power at the pump, then you might want to test the fuel pump relay.

Bitter

My first guess is a clogged fuel filter, an easy and cheap fix if you haven't done it previously. The symptoms of a clogged filter is a car that will run for a while, then bog down and die. After letting it sit for a while, it will run again but eventually the same problem will recur.

If that's not the problem, checking the SJB for moisture is worth doing. Early S197's are prone to that.