[UltraBlue]

Ok, I got a 1991 mustang gt 5.0 with an auto trans. The starter solenoid sticks once in a while, but it only does it at random times. It will stick about 1 out of every 100 starts. I replaced the solenoid 4 times in the car, replaced the ignition switch on the column, replaced the battery, and the battery cables, and the solenoid wires are hooked up right. I am out of ideas. what else could it be? tfi module on the distributor, neutral safety switch, alternator, voltage regulator? Thanks!

[rmiller86]

have you tried replacing the starter?. Usually it is the fly wheel and the berring that are starting to go in the starter which will cause it to not turn over or jump.. I had replaced mine at 150,000 and the one i replaced did the same thing. i finally replaced it at 200,000 miles. No issues now.

[UltraBlue]

the starter in the car is suppose to be new, but i will be getting a new starter tomorrow. besides that i cant think of anything else that i haven't replaced in the starting system. this is driving me nuts. the starter will just decide to stick on running at random times.

[spdjnky_42]

Sounds like it needs some shims

[UltraBlue]

ok, ill get a new starter and shim it today. what gets me though is that the starter only sticks at random times, and when it sticks if i take the battery cable off, and reattach it, it will stop sticking, and it will start normal again till the starter sticks again some X starts later. because of this i would think the problem would be in the circuit that energizes the solenoid?

[silver69]

if not faulty starter you could have a weak or loose ground between the battery, chassi and engine. just bcause a wire is present does not mean its good, copper breaks down, replace the ground cales. also make SURE your solenoid is tight on the firewall with no paint/rust/scale/loose bolts or sheetmetal screws.

[wv109323]

We have some terminology issues. The starter relay is on the inner fender near the battery. This relay uses a small low amperage coil to pull in the contacts in so that full battery amperage can be applied to to the starter motor and the starter solenoid. This allows the switching to use small wiring as opposed 2/0 copper cables. If not you would run wire the size of the battery terminals up to the ignition switch and make and break the starter current in the ignition switch.
Once the starter relay is make up, the power from the battery goes to the starter solenoid and starter simutaneously. (this is done through the starter cables:large wires)
The solenoid (located in the starter)also called the Bendix drives the starter pinion gear into mesh with the gear on the flywheel. The Bendix commonly has a set of contacts that then apply voltage to the starter motor and thus the starter motor turns the flywheel/engine.
When the engine starts the ignition switch is spring loaded and the spring returns from the start position to the run position. In the run position the starter relay releases thus removes voltage from the starter motor and the solenoid.
The starter has two ways to release the Bendix. ( disengaging the Starter motor pinion gear from the mesh of the flywheel gear) One is a simple coil spring and others use a magnet to (engage) and release the bendix.
A sticking starter then can be only two things. The Large contacts in the starter relay weld together and continues to supply voltage to the solenoid/starter motor. This can happen with hard starting cars where the relay contacts are engaged for longer times building up heat and thus welding together.
The other option is that the Bendix does not release. This can be a broken coil spring, a spring that has lost its tension ( due to heat) or crude that accumulates that mechanically blocks the travel of the bendix. A starter with a spring return is a poorer design that the magnetic. The force of the Bendix has to be stronger than the spring or the spring has to be weaker than the engagement of the Bendix. A magnetic solenoid can have equal forces to engage and disengage the bendix.

[spdjnky_42]

well either its getting hung in the fly wheel spin or has a sticking soleniod

[RWOOD126]

First of all ....these starters don't have shims. They are direct bolt on.

My was doing the same thing....then one day it wouldn't disengage and burned up the starter and battery cables.

Need to go ahead and replace it before it gets worse. Replace the starter with the high torgue starter and it'll last a whole lot longer.

[UltraBlue]

Thanks for the help guys! As I said before I will go and turn the key to start the car and the starter will stick running, continuing to try to start the car. If I turn the key off and take it out of the ignition the starter will keep trying to start the car, even with the key out. I then have to take the battery cable off to stop the starter from running. It doesn’t stick every time I try to start the car, as I said only 1 out of 75-100 starts or so. The ignition switch, solenoid, battery, and cables were replaced. So this means it has to be the starter that is causing the problem right? But if it is a defective starter, would it still try to start even with the key off and out of the ignition?

[ken4d]

i went thru 3 or 4 starter solonoids the one on the fender this us your problem the thin wire that plugs on to the solonoid comes from the ign its only purpose is to temp orarrily send power pulse to open the solonois which sends 12v to starterif when starting that wire pulse poweronly when the key is turned should not have power ones statred if that is working then the solonoid is getting stuck with a thru connection get a heavy duty solonoid NO AUTO ZONE FOR ELECTRICAL PARTS YOUR POBLEM WILL GET WORSE AS THE SOLONOID WEARS OUT TO STOP THE STARTER FROM CRANKING PULL THE LITTLE RED WIRE WITH THE PUSH ON BOOT