Ok. I have a 350 motor out of a 1971 C-10 p/u. Has repeated starter issues. I've tried everything from shimming, high torque vs. low torque, re-ran electrical, installed a brand new ignition switch, heat shield, gave a better ground, and the same thing keeps happening. After a few starts, it starts grinding, but will start, then starts free spinning. It progressively gets worse. then try something new, works for a while, then does the same thing. Recently had the trans rebuilt, and had someone look at the flexplate, and says it seems to be ok. minor wear on the teeth, but shouldn't be enough to cause any issues. When I tried a low torque starter as recommended by a local armature shop, it worked great and was nice and quiet for almost 2 years, I thought i had the problem solved... then out of nowhere it started again and i'm in the same position. It's hit or miss whether it actually turns enough to start, or even grabs the flexplate or not. I'm at the end of my rope with this and it's enough to make me want to get rid of the car. I'm beyond frustrated. Any suggestions on how to diagnose what's actually causing this issue? I've sunk enough into trial and error with different starters and shimming etc. Here's a video of what it does. It did have enough juice by the way... Notice the frustrated laugh. It's hard to hear, but what's happening is that it starts to turn then free spins (in the beginning) then grinds and eventually catches. This will happen a few times, and eventually just never catch at all, then it's dead in the water. EDIT: I've noticed that there are times when this happens, and i can get under there with the flat end of a tire iron and actually push the flex plate and spin it a little, and sometimes it'll catch and start. Other times it won't budge.
Could be a bad battery believe it or not. They get to where they won't pull the amps. My cure you are not going to like, buy a high torque mini. They sound like a MOPAR starter but they start the car. The sound of the starter is not nearly as nice as the sound of the motor.
Would that be something obvious to the naked eye? Doesn't seem to be anything there, but it does make sense.
do the battery cables connect directly from the battery to the engine block (ground) and starter (positive)? or does the battery sit in the trunk, or somewhere, and has the negative connected to the frame?
I've noticed that there are times when this happens, and i can get under there with the flat end of a tire iron and actually push the flex plate and spin it a little, and sometimes it'll catch and start. Other times it won't budge.
have you looked at the teeth of the flex plate have seen were one spot will be more worn than others engine usually stops in the same spot with a quick look all looks good but you have to inspect every tooth to see if it is meshing good
I would take another look at the flex plate. I have had to file down the mount on the starter on some engines to get them to fit correct.
Doesn't sound like the teeth are not engaging, which would be an indicator of a bad ring gear and/or bendix. It sounds like it's dragging. I saw your responses to Squirrel, have you put a volt meter on the battery while you're cranking it over and watched what happens to the voltage? If you've got access to an amp meter that will read high enough amperage, see what kind of amps the starter is pulling as it drags like that.
Measure voltage at start connection on solenoid. You might want to check it disconnected also, to see how much voltage comes thru key to trigger solenoid. If you are getting 12 volts there, you might be headed for the Ford solenoid hot start conversion. Another test would be to watch the starter-to-ring gear interaction from underneath. That should tell you a lot.
I don't have a ton of experience with this stuff. What should i look for that would be a smoking gun with either test? Is anything less than 12v an issue or is there wiggle room?
Sounds crazy, but a friend was having a similar problem and he found that the flex plate had been installed backwards. Worked for a while then starter wouldn't engage, then sometimes it would. He did all the things you have done, and in the end it turned out to be the flex plate! Good Luck, KK
I have found that once you get the problem solved installing the support bracket keeps the problem from re-occurring.
Something else that no one has mentioned.What condition is your block plate in?Was having the same problem with my DD(OT).Its a 300 ci Ford six.ALL of the holes,including the alignment dowel holes were worn oblong.Replaced that and the starter problems disappeared. Good luck.Have fun.Be safe. Leo
My first thought was also that the starter was moving around. Did you use the proper knurled bolts to mount the starter?
Voltage should not drop below 9 while cranking. If it does it indicates either a weak battery, or the starter is dragging and drawing more current than the battery can supply. That's why I suggested the amp meter, so you can tell how much current the starter is drawing.
You want as much voltage as you can get thru key to trigger solenoid. Try the info above and if it is any lower, start checking wires, cleaning connections at key switch, and checking voltage along the circuit to identify where the drop is occurring. Make sure you have 12+v at big starter lug. Be careful if you get under car, but the idea is to watch starter in action. If drive comes out solidly towards ring gear, that part of solenoid is working. That action should switch on starter motor and gear should turn. If engaged but not turning flywheel, something is wrong inside starter (dragging). If it doesn't engage or pulls back and spins, it could be the bendix (which is replaceable).
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