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Starter problems

Discussion in 'General Mustang Discussion' started by Horseplay, Jun 6, 2017.

  1. Horseplay

    Horseplay Well-Known Member

    Let me start by saying I'm exhausted and likely have done something stupid but for the life of me I can't seem to figure it out. My starter will simply not disengage once the engine fires. I've gone through the electrical and it is correct and the solenoid is not sticking, etc. This has to be a mechanical issue.
    302, T5 with correct bellhousing (came with trans), 157 tooth flywheel and yes, block plate too.
    Started out with a DB Electrical mini-starter. At first assumed I had an electrical issue due to the PM motor but not the case. Swapped in a stock 1990 standard style, single cable connection unit. Same deal. I've measured the depth of the flywheel from the block plate surface and compared to the seated bendix gear position and those measurements show adequate clearance. Still does it. Found out about a starter shim for Fords (never in my life have I had to use such). Installed one (.100" thick) to move a bit farther back. Still happens.

    What the hell am I missing?

    Here is a pic of the carnage done to my original mini starter. It looks like the gear sat in just a bit too far and had the front of the teeth filed back but then got pulled in and frozen while the flywheel ate it up. This happened on a new flat tappet engine so I had the throttle rigged to jump up to 2500-3k rpm so it happened quick. Haven't pulled the stock one back out again, yet.
  2. kb3

    kb3 Well-Known Member

    Didn't you let Mark touch your car at one time?

    Other than that I am no help, it sounds like your setup is identical to mine and I've not had that problem.
    msell66 likes this.
  3. Boom

    Boom Active Member

    I seem to remember there is something in the wiring if you use a mini style starter that will cause the starter to stick for a second after the engine starts. Issue with the solenoid wiring maybe.
    67stang likes this.
  4. Horseplay

    Horseplay Well-Known Member

    That's a real issue but not mine. Mini starters are PM (permanent magnet) motors that can generate voltage which if you try to wire them using the main starter power cable jumped to the on-board solenoid can result it the starter "locking" itself on. I had mine wired correctly with a separate wire to fire the solenoid.
  5. Horseplay

    Horseplay Well-Known Member

    On the advise of {.}...yeah, I know...I removed a few thousandths of material on the outside section of the block plate hole to allow me clock the starter a very minor amount to decrease the gear mesh a a few thousandths. Seems to have cured it. At least the time I just tried it. To late to fire it up now. Neighbors. Will play more with that in the morning. Let's hope this one is licked. Nothing is ever easy on this car.
    msell66 and RapidRabbit like this.
  6. B67FSTB

    B67FSTB The NorCal dude from Belgium

    For a T5 setup , you need a starter for an automatic trans ?
    Grabber70Mach likes this.
  7. msell66

    msell66 Burning Fossil Fuels Donator

    It's a weird thing with the mini starters. You need the opposite of what the tranny is.
    Grabber70Mach likes this.
  8. msell66

    msell66 Burning Fossil Fuels Donator

    If you would have listened to the rest of my advice, you would've finished the car a month ago.
    tarafied1 likes this.
  9. gt289

    gt289 Member

    Yeah, I don't know about that blanket statement. Both of my cars have mini starters, one is manual trans and the other is an automatic.
    Both use the same exact starter...... has to do with the placement of the ring gear. That's the reason it works right.
    I always line starters up with that rationale. (what's the amount of bendix movement, where is it when the engine is started and where is it at rest and where is the ring gear located from the mounting point of the starter)
  10. 3175375

    3175375 Well-Known Member

    Love your sig pic, Markie Mark. Reminds me of the days I ran a demolition Derby car. Purposely mounted a can of trans fluid in the cabin with a valve to dump it into the intake manifold. Created almost as much smoke as you did.
    msell66 likes this.
  11. bartl

    bartl Old Fart

    You say "single cable connection". This is your problem. You need to remove the buss-bar or other connection on the starter between the big lug and small lug or pin. You then need to reconnect the starter load cable to the FRONT or battery side of your fender-mounted solenoid and run a new 12awg wire from the REAR or "starter-side" of the fender mounted solenoid to the small lug or pin.
  12. Horseplay

    Horseplay Well-Known Member

    No, I had all the wiring to the starter correct. Separate wires for solenoid activation on the starter itself (same wire that fires fender solenoid/trunk in my case) and the big feed wire to the starter itself. This is a fully custom, trunk mount battery set-up. In addition I have many other custom electrical things going on. I traced my starter problem back to my "engine protection circuit". Basically, I ran power to my electrical fuel pump relay through a GM oil pressure switch. No oil pressure would prevent the engine from starting. Switch is single pole NC-C-NO connections. Simple stuff. Somehow the wire on the NO post was getting connection to the NC post...which should never happen. The NO wire is the same that sends juice to the starter solenoid (that way when cranking before oil pressure is created the engine can get fuel). Switch checks out with my meter. Still a mystery. I just pulled the plug on it, connected the C to NO wires and all was good. Teach me to us GM crap in my car!
    bartl likes this.
  13. Mach1 Driver

    Mach1 Driver Active Member

    Since none of the auto companies will share their design data like switch ratings, you really don't know you are overloading a component in a custom circuit until it fails. Sounds like it was driving a big inductor, which is always a difficult load.
  14. Horseplay

    Horseplay Well-Known Member

    I figured the load was more than it liked but all this went down during my marathon session in trying to make the Tour. Now that I missed that...again...I will revisit this circuit. Likely have to let the switch control a relay which in turn will carry the solenoid coil load. I've lost count now how many relays and such I have put into this thing. Way back when I contemplated pulling a relay/fuse panel out of a newer car and adapting it. Probably would have been easier in the long run. Next time.

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