83 olds 88 wants to keep on crankin' even with key OFF!! Help!

jake1960 · May 29th, 2005

Here's a pisser! I have an 83 Olds Delta 88. Last year the starter motor quit on me probably from excessive cranking. After sitting at least 12 months I got a new starter motor and installed. First time I cranked it the starter motor cranked and did not stop cranking even after I turned the key off for about 20-30 seconds. Next try it worked fine and engine started right up. Since then the next 10 times it continues to crank and not start engine with the key off. I have replaced the switch on the top side of the steering column thinking the spring action was shot. No difference. I have removed the starter and tested it on the garage floor with jumper cables. Works perfect. I re-installed and it continues to function ABnormally. Any help is greatly appreciated. Jake

rocketraider · May 29th, 2005

My guess is that you have either a bad solenoid or some wires are crossed or touching at the starter post. The starter wires often get oil soaked and insulation breaks down. I'd check all those out first.

jake1960 · May 30th, 2005

Thanks Rocketraider,
The solenoid is new as it came on the new starter motor and seems to work just fine on the garage floor. (I did check as I realize it is possible to get a bad new part sometimes, Murphy's Law)

The wire problem seems more right, since this was overcranked last year perhaps the wires got too hot and melted together? I would guess then, the small wire to "S" terminal on solenoid must be touching something?? where it shouldn't be? Can anyone tell me where each wire goes to or comes from on this curcuit? There is the Battery cable which I know goes to the battery. Then there are 2 more heavy (10 gauge?) wires on the same post with batt cable. Then 1 small wire to "S" on the solenoid.

All help is appreciated,
Jake

rocketraider · May 30th, 2005

The purple wire is the solenoid trigger wire from ignition switch. Goes to "S" terminal. The others are fusible links feeding the rest of the car's electrics and go on the starter post. I had one of those break in half from corrosion and oil damage on my 83 wagon.

jake1960 · May 30th, 2005

I think I'm going to lose my mind.
I took the starter back out. Traced all wires back to the block on firewall. Saw no melted areas or broken spots. Retaped with elec tape.
I layed the starter on the inner fender. I ran a separate ground wire to the housing from the battery, hooked up the other solenoid wires and tried the ign switch. Works great. Spins when I turn the key and stops spinning when I let go of key.
I then re-installed the starter again and hooked up the wires. Reconnect battery cable, tried the switch and starter engages and continues to crank after I let go of the key. It did start the engine 1 time and then it just cranks all by itself when I tried the next 10 times, funny thing is it doesn't sound like the engine is trying to fire and it does not start up and keep starter engaged as you might think. It seems as if there is no spark when the starter malfunctions and once in a blue moon when it functions properly the engins starts up immeadiatley as would a fine tuned automobile. Please where do I look next?
Thanks in advance for all help or ideas,
Jake

jake1960 · May 30th, 2005

Is it possible the solenoid on the new remanufactured starter motor is bad, but why would it work properly when on the floor and not installed?
Hmmmm....
jake

Silverbird · May 30th, 2005

Did you check if the starter is shimmed correctly? If the starter is staying engaged the clearance may not be enough. Sounds like the starter drive is meshing to tightly with the ring gear. When this happens the starter will not disengage the flywheel and will continue to run.
With the starter bolted up,check if you can get a 1/8th dia. rod(drill bit) between the starter shaft and the teeth on the flywheel. If you can't, add some shims.If the 1/8th tool is too sloppy or loose,remove some shims.
See if this helps any. Good Luck!

jake1960 · May 30th, 2005

OK thanks for this idea. I have heard about shimming the starter years and years ago but never actually had to do it. May I ask why the starter motor would keep cranking if there is NO power to it whether it is shimmed or not? Why would the starter motor continue to crank if the key is off whether shimmed correctly or no shims at all? What am I missing here?
Thanks, Jake

Silverbird · May 31st, 2005

Good point Jake. Let me see if I can explain it correctly.
First,main battery cable is going to the solenoid(hot power all the time).
When you turn the ignition to start the small wire(purple?) completes a circuit which enables the positive battery cable to electro-magnetically(sp?)pull the plunger in the solenoid which engages the drive gear with the flywheel AND completes the circuit to power up the starter motor(all at the SAME TIME). When you release the key,normally it disconnects the power from the solenoid plunger and the spring pushes the plunger back disengaging the starter drive from the flywheel and turning off the starter motor.
OK,when the starter sticks and doesn't disengage (the spring in the solenoid can't push the plunger back)especially when the starter teeth are basically jammed in the flywheel,you can turn off the key (turn off the power) but because the plunger is still engaged,there is still power going through the starter motor. The plunger inside the solenoid is what completes the circuit to engage the starter and as long as the plunger is in contact with that circuit,the starter will continue to run.
The only way to really stop the starter when this happens is to disconnect the battery cable from the battery. Then there is no power going to the starter.

Sorry about this being such a long and wordy explaination!
I could probably explain it faster in person! If you have an old starter lying around,take the solenoid off of it and you will see how the plunger and spring work with the gear.

Were there any shims on the old starter? Almost all Oldsmobile auto trans cars need shims. Manual trans cars rarely if ever need them.

I'm pretty sure this is your problem especially since you bench tested the starter off the car and it worked fine.
Let me know what you come up with.

Steven

jake1960 · May 31st, 2005

THANKS Steve!
This now makes more sense to me. I appreciate long and wordy explanations. I didn't realize the gear is completing the curcuit so power is still present until gear is no longer touching flywheel. That explains why it work perfectly on the bench.

The old starter did NOT have any shims that I saw. Can you explain what they look like or can I pick some up at Autozone or the like? Can I use washers?

I knew it has to be something simple as it started up like a brand new car a couple times.....didn't hardly even crank 1/2 revolution.

I will get some stinkin shims and let you know how I make out....it's such a long walk into town...

Regards, Jake