Starting problems...need some advice

[86lxttop]

I rarely have car troubles but I ran into a but yesterday... I'll start by saying it's an 86 Ttop 5.0 with a 90 engine (mass air, bolt ons, etc) battery is in the back and a 130 amp sn95 alternator conversion (one wire). I was driving the car yesterday and I stalled it in traffic and couldn't get it restarted. Seemed like it didn't have enough juice to turn over. Had someone come jump me and everything seemed fine. Got the car to my aunts and turned it off. Tried to start it an hour later and wouldn't crank... Lights and everything come on etc. Jumped it again and it seemed to take a little longer for the car to receive enough charge for it to turn on. Let it run for about 5 minutes turned it off and sure enough tried to crank it and nothing. Seems like it doesn't have enough power to turn the starter. Fast forward to this morning. Took both the alternator and battery to be tested at oreilly and they both passed. Somewhat stumped at the moment. If anyone has had a similar problem let me know or any other ideas would be greatly appreciated. Thanks in advance

[stephen4785]

Sounds like the starter is crapping out. Take a volt meter and stick it to your battery. Crank it and see what the voltage goes down to. AN amp clamp on the positive cable to the battery would let us know how many amps its pulling(dont know if you have access to that or not).

[Chas_svo]

And check your grounds.

[86lxttop]

Update...when I had the battery tested, they charged it also. Took the battery and alternator back to my car, installed it and it fired right up. I got it all the way home and it seemed fine. Check the battery voltage with the car running and it was at 11.93v turned it off and on a few times (luckily it restarted) let it run for a bit longer and the battery voltage was at 11.79 and seemed like the voltage went down .02 volts every minute or so....kinda weird. The only thing I could maybe think of was when it initially died I tried to restart it like 20 times so maybe I hydro locked it and it was too seized to restart with the normal battery volts? Or yes I need to check all my grounds and maybe even scuff them up a bit and reground them.

[86lxttop]

Sounds like the starter is crapping out. Take a volt meter and stick it to your battery. Crank it and see what the voltage goes down to. AN amp clamp on the positive cable to the battery would let us know how many amps its pulling(dont know if you have access to that or not).

Ya I have a meter just not an amp clamp...buying one is on my to do list

[0393gt]

Sounds like a bad battery. How old is it? I had autozone test my battery, they said it was good, but I knew it wasn't... new battery fixed it.

[jw33]

11.9 is way low with the car running. You probably have a charging issue. I would go over the wiring on the alternator and make sure nothing burned up or came loose.

[bird_dog0347]

Starting problems...need some advice

Also check the fuse that you should have inline on the 4ga power wire from the alt and make sure it's charging.
You can see how I have mine in this pic under the master cylinder.

[UserX]

11.9 is way low with the car running.

This.

[UserX]

Is the output on the back of the alternator the same you're seeing at the battery?

[0393gt]

voltage at battery should be around 12.25 with the car off, and about 14.25 with the car running. That's what mine does anyway..

[bird_dog0347]

voltage at battery should be around 12.25 with the car off, and about 14.25 with the car running. That's what mine does anyway..

Agreed, check the voltage coming off the alt, not at the battery.

[86lxttop]

Ya, an update...my car is definitely not charging at idle. Not sure what it is. Had both alt and battery tested and passed. Any way to do it and see for myself? I don't have an amp clamp. I need to buy one obviously

[jyro]

stock pulleys?

Ya, an update...my car is definitely not charging at idle. Not sure what it is. Had both alt and battery tested and passed. Any way to do it and see for myself? I don't have an amp clamp. I need to buy one obviously

by chance will the voltage go up when you rev it up

[86lxttop]

Ya it does.. I little but though. I drove it about 12 miles and the voltage was definitely lower than normal but I let it idle for about 6-8 minutes and the voltage slow crept down until I turned it off, tried to restart it and wouldn't turn over (dead battery)