Starting Problems

This question is for my roommate. He has a 98 Toyota 4Runner but is having problems with it starting. The other day it wouldn't start but he took the connectors off the battery terminals and there was some corrosion on them cleaned it off and it started. This morning it wouldn't start for him, even after I jumped him. It will turn over but the engine wont start. I was thinking he needs a new battery but he said that the lights and everything still turns on. Any suggestions would be much appreciated

I think you're right. He probably needs a new battery. Lights and such draw insignificant current compared with the starter. Current capacity is the necessary component for starting.

... This morning it wouldn't start for him, even after I jumped him. It will turn over but the engine wont start. ...


Yeah, but if it will turn over but not start while being jumped ...

that confuses the issue a bit.

Might be two different issues.
First, what caused the battery to go dead in the first place. If he cleaned the connections and it started, I would re-check his cleaning job.
Now that he knows the terminals are dirty/corroded, what about the connection from the cable to the terminal. The cable to the starter.
Most ignition systems voltage comes off the starter where the main lead hooks.
If there is no reason for the batt. to be dead, have the batt. load tested for free at a local auto store.
Are you letting the batt. take a good charge before trying to start it? Or is it cranking slow.
It may just be flooded too from all the slow cranking