Car Randomly Shuts Off

Today i was driving down a 45mph road in the middle of a pack of cars and my car just turned off and wouldnt start again. i had to put my hazards on and roll to the side of the road and get honked at. a cop jump started it for me and it was fine. my battery is about 3 months old. i had just charged it up all the way last night. anybody know why my car might be doing this? thanx
 
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You lost either fuel or spark. If it does not do a restart immediately after shutting off, the following check list will help

Cranks OK, but No Start Checklist for Fuel Injected Mustangs

1.) Remove push on connector from starter solenoid and turn ignition switch on. Place car in neutral or Park. Remove coil wire from distributor & and hold 3/8” away from engine block. Jumper the screw to the big bolt on the starter solenoid that has the battery wire connected to it. You should get a nice fat blue spark.
Most of the items are electrical in nature, so a test light, or even better, a voltmeter, is helpful to be sure they have power to them.
No spark, possible failed items in order of their probability:
A.) Coil
B.) TFI module
C.) PIP sensor in distributor
D.) ECC relay next to computer
E.) Fuse links in wiring harness
F.) Ignition switch
G.) Computer

2.) Spark at coil wire, pull #1 plug wire off at the spark plug and check to see spark. No spark, possible failed items in order of their probability:
A.) Moisture inside distributor – remove cap, dry off & spray with WD40
B.) Distributor cap
C.) Rotor
D.) Spark Plug wires
E.) Coil weak or intermittent - you should see 3/8" fat blue spark with a good coil

3.) Spark at spark plug, but no start.
Next, get a can of starting fluid (ether) from your local auto parts store: costs a $1.30 or so. Then pull the air duct off at the throttle body elbow, open the throttle, and spray the ether in it. Reconnect the air duct and try to start the car. Do not try to start the car without reconnecting the air duct.
Two reasons:
1.) If it backfires, the chance for a serious fire is increased.
2.) On Mass Air cars, the computer needs to measure the MAF flow once the engine starts.
If it starts then, you have a fuel management issue. Continue the checklist with emphasis of fuel related items that follow. If it doesn’t ,then it is a computer or timing issue: see Step 4.

Clue – listen for the fuel pump to prime when you first turn the ignition switch on. It should run for 5-20 seconds and shut off. To trick the fuel pump into running, find the ECC test connector and jump the connector in the lower RH corner to ground. See http://www.mustangworks.com/articles/electronics/eec-iv_codes.html for a description of the test connector. If the relay & inertia switch are OK, you will have power to the pump. Check fuel pressure – remove the cap from the schrader valve behind the alternator and depress the core. Fuel should squirt out, catch it in a rag. Beware of fire hazard when you do this. In pinch you can use a tire pressure gauge to measure the fuel pressure. It may not be completely accurate, but you will have some clue as to how much pressure you have

No fuel pressure, possible failed items in order of their probability:
A.) Tripped inertia switch – Coupe -& hatch cars hide it under the plastic trim covering the driver's side taillight. Use the voltmeter or test light to make sure you have power to both sides of the switch
B.) Fuel pump power relay – located under the driver’s seat in most stangs built before 92. On 92 and later model cars it is located below the Mass Air Flow meter.
C.) Clogged fuel filter
D.) Failed fuel pump
E.) Blown fuse link in wiring harness.
F.) Fuel pressure regulator failed. Remove vacuum line from regulator and inspect for fuel escaping while pump is running.

4.) Spark & fuel OK.
A.) Failed IAB (no airflow to start engine). Press the throttle ¼ way down and try to start the car.
B.) Failed computer (not very likely)
C.) Engine ignition or cam timing off only likely if the engine has been worked on recently).
D.) Firing order off: HO & 351 use a different firing order form the non HO engines.
 
Just put a new alternator on it, and have the battery load tested. Mine would do that also, but only at night wheh I had the lights on. It was fine during the day, I also have underdrive pulleys so that will slow the alternator down. I got a new one and It has fixed the problem. I also put new battery cables on while I was at it.
 
JR is right. if you can make it do it again, check FP if you have a gauge or check spark and go from there. you could even have a FP or EEC relay that is burping.

gotta narrow it down - i know the intermittant stuff like that sucks (JR was helping me with the same issue on the 4 gen camaro). :nice:

good luck.
 
shttygtstang said:
jrichker them are some huge check lists you have there i see um all over what do i do about blue balls ????????????????

Well, first things first. Check that your penis is functioning correctly. If you do not get an erection you must narrow down the possibilities beginning with probability.

A). You have no dick.
B). ****'s not good enough anymore.
C). Chicks you get with are butt.
D). You have erectial disfunction, call up Bob Dole! He can hook you up!

haha jk man
 
there was a ground wire coming from the battery that wasn't connected right. since i put it back on i have started the car about 10 times and its been fine. i have no idea if that was the problem or not... we'll find out. if it keeps acting up i will just put my car to sleep a little early and start the HCI install. thanx guys
 
If previous posts don't help, check the wires coming out of the side of the alternator. they get hot and break down. They may look fine but run them through your fingers and see if they are weak. Local parts store has a replacement plug for this. Also check the ignition switch. Not the key switch but the ignition switch located on the right side of the steering column. It is screwed on with two knock off screws. The part that screws to the column is cast medal and has a plastic connector that is held on with a couple medal ears. After time these "ears" wear out and the medal and plastic comes apart . This will cause your car to randomly break up if it is not seated correctly and stall if it comes apart far enough. I would think it is the alternator or the wires but, both have happend to me.