Hi guys

Winter has passed here in good old Belgium so i wanted to start up the 'stang after standing still for 3 months. No success. Battery seemed to be dead. I recharged the battery and today the engine starts, but as soon as i let go off the ignition the engine stops running. Any idea's ?

Michael

 

Hi to Belgium from Ireland :-) my car's been in Belgium for a day before final shipping to Cork. probably stopped for a bag of chips ... :-)

just to clarify. you turn the key to "start" position. the engine starts cranking.
- Does the engine actually fire up and run at this stage?
- and it stops immediately when you let go the key so that the key is in ignition position? i mean does it just stop cranking (which is normal), or does it stop running after been running in 'start'
- when you start the car in 'start' and let go, can you keep it alive with pumping the accellerator?

Kalli

 

Hi

I turn the key to the "start" position, the engine cranks and it runs (I can here the V8 roar) but as soon as i let go of the key, the engine stops running. What i hear at that point is the starter engine slowing down. When I start the car in 'start' and let go, I can't keep it alive with pumping the accellerator. It just stops.

 

I'd start by running 12v straight to the coil (don't leave it this way for more then 5 - 10 min as the coil can overheat) and try staring it again. If it runs then its most likely the ignition switch.

Any chance of furry creatures nesting in the car during those 3 months?

 

same as tcrotes approach
from your description what seems to happen is that your coil is gettiong 12V+ while cranking, but as soon as you don't crank anymore it's getting no voltage or too little voltage.

the way this works is that there's a cable from the starter selonoid 'I' port going straight to coil+. when you crank the selonoid will give the neeed voltage to coil as usually everything else brakes down during crank.
So this seems to work fine. whaat doesn't seem to work is that the 12V+ the ignition should be giving to the coil (this is normally only around 8V+) is not happening.

1. if you have a voltmeter or a testlight check if you are getting voltage at coil+ with ignition switch in 'ono' position. if not, then this is exactly your problem.
2. if that's the case the first thing I'd try is to disconnect the connectors at firewall, clean them and try again. maybe they got a bit rusty ....

here's a simplified wiring diagram I once made so you know what I mean



and the artcile for it (but ignore the testing steps in it, they are only for people when it doesn't crank)
http://www.gascc.ie/index.php?option...y=73&showall=1

 

Just ran a wire from the + pole of the battery to the + pole of the coil. Engine fired up and kept running until i removed the wire. So it's probably the starter solenoid that's failing ...

Correct conclusion ?

 

No, the problem is not the solenoid, the issue will be in a problem in the ignition circuit.

When you turn the key to "start" the coil receives a full 12V directly from the solenoid to facilitate cold starting. When the key is released, the ignition circuit (powered from the key switch) is supposed to take over to deliver about 8 volts to the coil (voltage drop is achieved from a resistor wire in the circuit).

What is happening, is your car is starting fine on the "start circuit", and then the ignition circuit is failing to deliver power to your coil to keep the car running.

I would check all connections closely, I suspect a broken terminal connection or a wire broken under the insulation near the end of a wire. I would check the wires that attach to the + side of the coil first.

It could be the ignition switch itself, but if other components come on that are supposed to come on in the key in the "run" position, (wipers, gauges, etc) I would lean more toward a poor connection or broken wire.

I am unsure as to whether the stock wiring on these cars includes a fuse in the ignition circuit, but it is advisable to check the fuses before you get too far along anyway.

Get yourself an electrical test light, they are cheap, but priceless when it comes to tracking electrical issues. I would be lost without mine!

 

It sounds like a ballast resistor problem (I've had it happen on a Subaru) - troublshooting the coil input voltage as described above will isolate the problem.

Good luck,

 

2 Golden tips. I used my test light to check the different connections. No voltage arrived on Coil + side when the ignition was in the on position. Checked the wiring where possible, it's a brand new painless wiring kit - most of it is insulated - so i would have been surprised if there was a broken cable ... checked the fuses and yep there it was ... a fuse for the ignition & coil ... all burned.

Replaced it , redid all the tests you guy's suggested and yep ... voltage on the coil

Mustang starts again flawlessly.


The cause ? Probably my garage. It's sometimes a bit damp, and when i tried to start it yesterday i heard some "short circuit" noises around the coil. It probably got wet inside which caused the fuse to burn. Garage will be fixed in the summer


Thanks Guys

 

the new wires pass through grommet in the firewall?

good to be sure its not a wiring short,