Starter spins super slow and won't start car
 

Hey guys. I'm really stumped by this one so I thought I'd ask if anyone has had a similar problem with this. So here's what's going on.

The car is a 94 formula. It was running fine and then the battery crapped out. So I got a replacement and then the starter would not spin the motor very fast. So I bought a new starter. The problem persisted. I put a starter from a currently running and driving F-body to see if I got a bad starter but it still would not spin very fast.

It's got plenty of oil, I ran a new cable from the battery to the starter. The new one being about twice the size of the old one...problem persists.

I cleaned all the grounds and reattached them and still nothing.

I checked the voltage of the bad car at the battery and it read 12.3 volts, then while cranking it read 8.3 volts at the battery. So then I tested the power at the starter itself and it was the same it only read 8.3 while trying to start. I did the same test on the good car and it only dropped to 11.5.

The battery also has new terminal posts and I cleaned all the connections too.

So it's losing voltage once I try to crank the car but I have no idea why. I've tried everything I can think of and still can't figure it out. I checked to see if the car was grounded well and it is. I did a resistance test from the battery to the motor and there was almost no resistance. I have no idea what to do and I really don't want to have to take it anywhere.

What could cause this problem and is there something I've missed? I've checked everything I personally can think of that would cause a starter to spin slow. Thanks a bunch in advance guys. I'm super stumped and it's starting to tick me off something fierce.

Zach

Spin it over by hand to see if it is an engine mechanical issue?

Get the new battery tested? Sure it has the proper cranking amp rating?

Have you tried jumping the battery? When it was running did you notice any problems?

Do you have your fans running off the ignition switch by any chance?

Have you tried cranking it by shorting out tge solenoid? May be something to do with the switch.

I'm sure you've already tried another battery...

Lastly but very unlikely, it could be hydrolocked. Pull a couple plugs if all else fails and check.

The car ran fine before the battery went. We also tried the battery from a working car and still nothing.

What do you mean short out the solenoid?

Fans are not running off the ignition switch.

Already had the plugs out before and tried to spin it but it still spun slow.

Your starter might be worn out, and it's sucking the juice out of your battery while your trying to start it...

Shorting out the solenoid-Take a screw driver and touch both sides of the solenoid on the starter (positive and ground) and it will short it out and cause the starter to turn. Make sure you get good contact. You may not be able to do this though depending on what kind of exhaust you have and how easy it is to get to.

take the starter out and bench test it. its odd if all of the starters showed the same issuse

I'll see about shorting the solenoid. The starter itself I don't think is the problem like I said I put a starter from a running car on it and it did the same thing. Something is zapping the power when I try to crank it but I just can't think of what it could be.

I only see 2 possibilities left given the testing you have done:

1. Engine is partially seized (physically hard to turn)

2. Battery cables not connected properly/damaged internally

Flywheel/pinion spacing too tight?

Still haven't been able to figure this out. It's not seized and I've checked all the grounds and wires but I can't figure out why I would be losing voltage during cranking.

Bench testing a starter wont always tell you its bad, but i have seen them go out very easy on lt1 cars for some reason, maybe the heat is to much for them or your starting habits

Correct test but incorrect description of test.

You do NOT want to short positive and ground together.

Battery positive voltage goes in one large power stud and comes back out the other and goes into the starter motor.

Short these studs together, not either to ground. Grounding battery power may cause an explosion.

You should not need to do this test as the starter is engaging indicating the solenoid is working correctly.

Onto your starter problem:

Agreeing with RamAir95TA, I think you may need to shim the starter away from the block a bit. Voltage drop at the battery during cranking is normal.
http://wzus1.ask.com/r?t=a&d=us&s=a&...jpg%3Fn%3D5261

I had this problem on one of my first cars and it was a bad battery cable. You should have 10volts when cranking. check the resistance on the battery cables with an ohm meter. See if thats the problem

maybe you just got a bad new battery? it happend to me before. try swaping batteries with the good f body. if not probably bad starter and\or needs shimed as stated already.

I've already checked the battery and it's just fine. It starts other cars we have with no problem. I checked the resistance from the battery to the block and there was very little resistance which leads me to believe the cables are not the problem.

Have you tried to jump start it as if you had a dead battery?

Have you had a chance to check the flywheel/pinion spacing?

What about the cable to the starter??? Grounds very rarley ever go bad, it's usually the possitve due to the load.