I have a 1970 fj40 plow vehicle that i have not started to restore yet. Last year I put in new battery,plugs,wires,cap and rotor, etc.. i cant seem to start it without jumping it. It's almost as if the battery doesnt provide just enough spark. Any ideas why. Like I said--the battery was brand new last winter. Thanks for any help

Brian

 

Take a look at the battery cables , they may be corroded .

 

I took the cables off and wire brushed them but they looked fine. no luck

 

So if you jump it, and let it run for 20 minutes or so (so you know the battery is charged), then turn it off and try to start it again right away, it won't fire? You have to jump it again?

 

Does it click when it doesn't start, or is it silent?

 

If you start it and let it run it will start right back up the second you turn the key. There is a noticable difference in the power going to the starter when you try and start it off its own battery vs. jumping it. I just dont think the battery is bad because you could turn it over for 15 mins straight before the battery starts to die down but for some reason the extra power comming from a jump will make it start right up--almost like the battery alone doesnt give the plugs enough of a spark but the minute you give them more power it fires right off. I just dont know what would cause that.

 

The battery has I think 980 or 1000 cca which was the most i could find without getting a tractor battery which wont fit in the compartment without modifing it. I guess its possible that i could have a bad battery but like i said, it seems fine, tests good just seems like something between the battery and plugs takes some of the power away but that doesnt make any sense to me

 

They may be corroded up under the insulation at either end, see if you can feel for unusual stiffness in the cable. And try putting a volt meter across the ends of the cable (i.e. one probe on the battery post and the other probe at the other end of the cable) and try starting. See what sort of voltage drop you get across the cable. And see what voltage you get across the battery while starting. If the vehicle is not used periodically, that new battery may have gone dead sitting the last year unless you had a charger or some sort on it.