Intermittent slow cranking

[E9erCS]

30-45% of the time my starter turns over very slowly; the rest of the time it "sounds" normal. Fortunately, the car always starts. Changing out the starter for a rebuilt one did not solve the problem. I have searched the forum for earlier posts on starter problems, but none of the postings seem to address this kind of problem. Anyone have any thoughts?

 

[dang]

Starter motors take a LOT of current, so if there's a possibility of any resistance it would turn slower. Check all connections and quality of the cables. If either one shows any corrosion I'd replace it.

Dan

 

[MMercury]

Connections!

I second Dan's suggestion. Cables or grounds may look fine, but you can't always judge a connection by its looks. Corrosion is not the only thing to look for though, a loose connection can have the same effect.

As a secondary issue, it is possible although not necessarily probable that you are running too much initial ignition timing. Or your battery just doesn't have the cranking amperage you think it has. Check the connections first!