'93 460 Fox Starting issue

[MBGT02]

hey guys i know this isnt a "5.0" question but wasnt sure where else to post it.. I just put a built 460 into my 1993 LX.. everything worked out great ( fitment wise ) however im having a starting problem.. The car has EVERYTHING brand new including wiring.. If its cold ( as havnt started yet in hours ) it cranks once or twice and fires up and runs great. if i turn the car off it will start up flaw-less MAYBE one or two more times then the battery is dead.. The battery is a year old and was tested great, all new battery cables and selinoid. im not sure if its a timing issue, possibly even still bad battery after being tested, the alternator guage says 14 volts, and i can pull the negative battery cable off and car still running. after i turn it off and back on 3 times i put the battery charger on and it says 0% and within 25 minutes its at 100% and starts again fine. So im not sure.. ANY input at all would be great guys.. thanks!!

 

[jka]

It could be a short in the alternator. If you get it tested it will pass... but the problem will not show up until everything is warm and when your engine cools off and instead of charging the battery it will pull power from the battery. Hook up a multimeter to the battery with the engine running .. voltage with the engine running should be 13.20-14.52 then turn on your lights and heater on high..the voltage should not go under 13.0 volts if it does replace the alternator. Next turn off your car and watch the multimeter..and if you can see your volts go down ..it's a short in the alternator. If the alternator is good and charging... your battery voltage should be about 12.52 or more after you turn your engine off.

 

[CarMichael Angelo]

hey guys i know this isnt a "5.0" question but wasnt sure where else to post it.. I just put a built 460 into my 1993 LX.. everything worked out great ( fitment wise ) however im having a starting problem.. The car has EVERYTHING brand new including wiring.. If its cold ( as havnt started yet in hours ) it cranks once or twice and fires up and runs great. if i turn the car off it will start up flaw-less MAYBE one or two more times then the battery is dead.. The battery is a year old and was tested great, all new battery cables and selinoid. im not sure if its a timing issue, possibly even still bad battery after being tested, the alternator guage says 14 volts, and i can pull the negative battery cable off and car still running. after i turn it off and back on 3 times i put the battery charger on and it says 0% and within 25 minutes its at 100% and starts again fine. So im not sure.. ANY input at all would be great guys.. thanks!!

That make zero sense.
Nothing will pull a fully charged battery to zero after three restarts. I'd say the "new" battery you have is suspect.
While this isn't it, The only other thing that I would blame a hot restart problem on would be a bad starter, (depending on how close the header tubes are w/ the starter)

 

[MBGT02]

I will have to check it with a mulitmeter! thanks for the help! and the header is awfuly close to the starter.. -__- but the battery like i said is about a year old. soo im not sure. I guess ill check the battery with a meter fist and try to see if its something to do in the alternator or battery.. Im not sure if this makes a difference however once i put the 460 in, i took out most of the wires for the computer and whatnot and re used the alternator wiring clip and all. im starting to think i need to wire the alternator up completely seperate.