Ignition Problem

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Dashbrazil

Well-known member
Joined
Jul 3, 2011
Messages
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Location
South Carolina
My Car
1972 Ford Mustang Sprint, 2V
Every so often I'll get back to the car after driving, turn the ignition and see my idiot lights flash on and get no crank. The car will be driving flawlessly before that. I'll sit and make a phone call or wait about ten minutes, then turn the key again and it'll crank and start but take longer than usual.

I figured it the ignition is going or there's a bad ground, but I don't understand why it would crank after sitting there a few minutes. I've checked all the wiring and there doesn't seem to be any problems.

I got caught up with work and haven't been able to get to the engine yet and have still got interior pieces I'm refinishing. But I'm thinking this might be a good time to pick up the MSD ignition and stop putting it off. Any ideas? :-/

 
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When the engine is heat soaked like in the scenario you describe, resistance is higher in the starting system components. If your ground system or starter are marginal you will experience the slow crank/no crank situation. Make sure all necessary grounds are present and in good condition. If you feel you need to replace a worn out starter, a high torque mini starter is worth considering.

Too much initial timing can aggravate the situation.

 
Pull the starter and have it tested. Odds are TommyK is spot on. 2 bolts are easier to find than all the grounds associated with the ignition

 
TommyK is right. Mine started doing just that, then I rebuilt the starter and it has been perfect ever since. One of the brushes was worn irregularly and was jamming in the "track" when it got hot.

 
I had this problem years ago and it turned out to be a bad connection where the ground cable bolted to the engine block. Cleaned up the connections and worked like a charm.

 
I had this problem years ago and it turned out to be a bad connection where the ground cable bolted to the engine block. Cleaned up the connections and worked like a charm.
That's my vote.

When you put the key in the crank position, do you hear a click of the solinoid? Do the idiot lights go off?

Here are a couple of things to try:

Next time, turn on the head lights. Try cranking. If the lights obviously dim then your solinoid is probably enguaging and sending power to the starter. If they do not dim then the solinoid isn't.

Get yourself a multi meter. Next time this happens you can pull the starting wire from the solinoid, the one closest to the battery and marked 's'. Set the meter to DC. Touch black wire to neg on battery, red wire to 's' wire. Have someone turn to the crank position. You should see around 11 or 12 volts. If you do then your ignition switch is working. Connect the 's' wire back up and place the positive test lead on the starter side of the solinoid. Have someone crank. You again should see 11 or 12 volts. If you do and the motor isn't cranking you have either a bad cable from solinoid to starter or a bad starter.

While you are at it, when you are having the problem, test volts across the battery. It should be almost 12 volts or higher. If it is less, then your battery is marginal.

 
will e, I'll check that next time it gives me a hassle which based off current trends should be the next time I'm in a hurry.

Tomorrow I'll check and clean the grounds and pull the starter. She's a slow starter already, so a new starter isn't a bad idea. I did check the battery and it's fine. I'll run a multimeter on the starting wire after school.

Thanks for all the help!

 
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