Starter runs, flywheel won't

Hi, 1996 Jimmy SL 4WD AT 4.3L.

Won't start. Starter runs (shoots solenoid and whirs) if it is unbolted and let rest out of the flywheel housing. Bolt it in just a bit and does the same. Bolt it in most of the way, still a bit loose: dash will make clicking sounds as if if solenoid trying to engage. Bolt it all the way in, tight, and nothing: just a single click of a relay behind the glove box (that's what it sounds like). Did the whole thing again: unbolt, pull loose, shoot and whir, bolt up; same deal.

I've had it a year. Was doing the same kind of thing a week after I got it, but it would somehow start after a while, and would start fine most times. Then last fall, it just refused to turn over despite trying several times over a couple of days. So I took the starter out, took it over to a rebuilding shop, they bench tested it, and said nothing wrong with it. I put it in and it started up just fine and has ever since until this week.

In its prior history, the starter motor has been replaced twice by the previous owner. I'm thinking that there was nothing wrong with the starters each time but rather there has been some problem with the flywheel or the engagement that prevents it from turning over.

Battery has been removed and charged overnight. No diff. Battery registers 12.86 volts. Dashboard voltmeter was registering 14 to 14 and a bit when running. Jumpered with another car; no diff.

Haynes manual mentions something about shims (don't seem to be any on the starter or housing). However, neighborhood repair shop says that from the symptoms described shims are not the problem. If I can get it in to him, he can diagnose it. He's treated me well in the past, so I'd like to get it to him without paying for a towtruck ($70 around here).

Could the flywheel be jamming the starter? Is there a way to move the flywheel? Car is automatic transmission, and I have moved it several times about 18 inches while in gear; no diff.

Help! Would like to get going Friday to pick up sibling at airport and use for the weekend. Thanks!

Hi, 1996 Jimmy SL 4WD AT 4.3L.

Won't start. Starter runs (shoots solenoid and whirs) if it is unbolted and let rest out of the flywheel housing. Bolt it in just a bit and does the same. Bolt it in most of the way, still a bit loose: dash will make clicking sounds as if if solenoid trying to engage. Bolt it all the way in, tight, and nothing: just a single click of a relay behind the glove box (that's what it sounds like). Did the whole thing again: unbolt, pull loose, shoot and whir, bolt up; same deal.

I've had it a year. Was doing the same kind of thing a week after I got it, but it would somehow start after a while, and would start fine most times. Then last fall, it just refused to turn over despite trying several times over a couple of days. So I took the starter out, took it over to a rebuilding shop, they bench tested it, and said nothing wrong with it. I put it in and it started up just fine and has ever since until this week.

In its prior history, the starter motor has been replaced twice by the previous owner. I'm thinking that there was nothing wrong with the starters each time but rather there has been some problem with the flywheel or the engagement that prevents it from turning over.

Battery has been removed and charged overnight. No diff. Battery registers 12.86 volts. Dashboard voltmeter was registering 14 to 14 and a bit when running. Jumpered with another car; no diff.

Haynes manual mentions something about shims (don't seem to be any on the starter or housing). However, neighborhood repair shop says that from the symptoms described shims are not the problem. If I can get it in to him, he can diagnose it. He's treated me well in the past, so I'd like to get it to him without paying for a towtruck ($70 around here).

Could the flywheel be jamming the starter? Is there a way to move the flywheel? Car is automatic transmission, and I have moved it several times about 18 inches while in gear; no diff.

Help! Would like to get going Friday to pick up sibling at airport and use for the weekend. Thanks!

You need it bolted back up to test or start.

Jumper 12 volts to small solenoid purple wire and see if solenoid kicks the starter drive in and turns engine.
Post back what that does.

Also check for 12 volts on small purple wire to solenoid key on start position.
If not trace back threw starter relay and saftey switch and start fuse and to ign start position terminal.

The flywheel/engine can be turned from the front of crankshaft at pulley bolt.

Thanks for your reply. Something worked, or I got lucky.

I turned the flywheel by turning the crank (front pulley bolt). No change.

Then I used a homemade insulated probe to poke 12 volts into the wheel well and touched the terminals of the starter. Touching one of the clearly made a sound like the solenoid whacking in.

Then after some more fiddling, I tried the starter again, preparing to do the start key test you suggested, and ... the Jimmy started!

So I ran it for a couple of minutes and then stopped it and turned the key and ... it started! So I drove it off to the local shop a few blocks away and parked it there so it will be ready for diagnosis and work, even if it doesn't start in the morning. (Was 9 pm and shop long closed.)

I'm guessing that maybe triggering the solenoid manually with the zapper did the trick. But maybe it required turning the flywheel first. Or maybe I was just lucky.

Regardless, thank you.

Good luck
And let us know how it goes.
You saved tow bill.
If the starter fails to kick in after 12 volts to solenoid it is usually bad solenoid or battery power to it.
If starter kicks in and no turn usually bad starter.
If starter kicks in and spins and fails to turn engine bad starter deive or flywheel.

A brand new not rebuilt starter not a rebuild is usually a good move if starter or solenoid or starter drive is bad.

Ended up replacing the starter, on the mechanic's recommendation. It better fix the problem.