New alternator, 60 won’t stay on at idle

[UGA2018]

So my alternator is shot. I tried to get it rebuilt but the shop said it was beyond repair. So after shopping around I got a remanufactered one from Napa. I installed it and as I normally do when my 60 is cold I pulled out the choke.

It cranked right up and the voltage gauge on the dash read 14v. Great! It’s charging.

After warming up for a few I push the choke in and it immediately died. It started right back up with the choke but with no choke it dies. Nothing else has been changed.

Thoughts on what’s going on here?

 

[pithicus]

sounds like a carb idle/fuel stop solenoid problem.

 

[UGA2018]

sounds like a carb idle/fuel stop solenoid problem.

Maybe… but why would it not be working now. It was before the alternator.

 

[pithicus]

Maybe… but why would it not be working now. It was before the alternator.

Easy to test. Put your ear to the carb and get someone to turn the ignition on. You should hear a click. No click means the solenoid is no longer getting 12v.
good luck.

 

[OSS]

Fully charge the battery overnight with an AC powered battery charger plugged into the wall.
A brand new alternator with functioning voltage regulator when charging a discharged battery, will put a big load on the engine at idle, possibly enough drag to make a cold engine struggle at start up.

When I got a new alternator, when I turned on the headlights, the engine RPMs would drop noticeably at idle as the alternator kicked in.

 

[UGA2018]

Fully charge the battery overnight with an AC powered battery charger plugged into the wall.
A brand new alternator with functioning voltage regulator when charging a discharged battery, will put a big load on the engine at idle, possibly enough drag to make a cold engine struggle at start up.

When I got a new alternator, when I turned on the headlights, the engine RPMs would drop noticeably at idle as the alternator kicked in.

Thanks @OSS . I just hooked up the AC battery charger. I’ll check back in tomorrow.

 

[UGA2018]

Easy to test. Put your ear to the carb and get someone to turn the ignition on. You should hear a click. No click means the solenoid is no longer getting 12v.
good luck.

I’ll check it tomorrow. Thx

 

[FJ60Seth]

Did you disconnect your battery when you swapped the alternator? If not, you might have fried one of the fusible links. One goes from the alternator to the battery.

 

[UGA2018]

Did you disconnect your battery when you swapped the alternator? If not, you might have fried one of the fusible links. One goes from the alternator to the battery.

I disconnected the ground but not the positive. Would that do it?

 

[UGA2018]

Ok I tried @OSS suggestion and nothing changed. Same issue. I took a couple of pics to see if that helped to diagnose it. It cranks right up and then dies when I put the choke in. Strange!

 

[UGA2018]

More info… I noticed some smoke coming from the firewall. I grabbed a quick video before I killed the engine. Thought this couldn’t be good. Ideas?

 

[UGA2018]

This is the alternator I got. Says 40 amps.

https://www.napaonline.com/en/p/RAY2138209

 

[2mbb]

Can you get it to run/start with the choke pushed in? use starter fluid or prime the intake with gasoline by pumping on the accelerator pedal (after confirming you can see gas in the carburetor bowl sight glass.

Based on your description I think this is more fuel related than alternator. If your battery is charged the car will run without the alternator. the choke doesn't have any electrical connection except for the light that comes on when the knob is pulled out.

 

[g-man]

that smoke is most likely an exhaust leak or oil burning off the motor. Did you spill any oil? is any oil leaking onto the manifold or exhaust pipe?

Agreed that the no idle issue is most likely not related to the alternator or the charging system. Fuel related or possibly a large vacuum leak.

Curious as to how your original alternator was beyond repair? I've been through all this, and I can say your are MUCH better off rebuilding the original. Aftermarket chinese alternators are junk. DONT throw away your old alterator! Take it to a better alternator shop.

 

[duncanrm]

Your new alternator is internally regulated.. was your old one internally regulated as well? I ask because the three wires to your alternator dont appear to have a factory plug on them. Did you do any wiring changes to get your new alternator in?

 

[UGA2018]

Your new alternator is internally regulated.. was your old one internally regulated as well? I ask because the three wires to your alternator dont appear to have a factory plug on them. Did you do any wiring changes to get your new alternator in?

Thanks everyone for your help! I’ve been tied up with work so trying to get back to this today.

No oil added recently. Doubt the smoke is oil related. Maybe burning off condensation but not sure.

I’m going to do a vacuum test but don’t think that’s it. I’ll let you know.

The new and old alternators are both externally regulated. See these pics for the regulator. The old one has the circular plug.

 

[UGA2018]

I’m wondering if I got my wiring off. Here’s a little better picture of that. I tried to mimic where things were plugged in and connected on the original. Not sure if that is right though. Thoughts on that causing the problem?

 

[pithicus]

I’m wondering if I got my wiring off.

Maybe. Have you checked your fuse box? That smoke could have been electrical. [fusible link fried]

 

[duncanrm]

The green plug is usually indicative of an internally regulated alternator. I really feel a solid look at how this is wired up is required.. starting with a good understanding of what you've actually got. Anyhow.. if its charging and your happy with the voltages etc - you can just ignore my thoughts.

 

[UGA2018]

I think they gave you the wrong Alt. Difficult to tell from the incomplete pix.

Looks like the one you're using now has no regulator.

Do you still have the old Alternator ?

@ToyotaMatt

What year is this FJ60 and is it a US-spec truck?

Thanks @Spike Strip. It’s a 1986 US spec 60.

When I first got it and before I started wrenching I had a guy work on it. He replaced the alternator with the now dead one. He said it came off a 62. I can’t confirm.

The wiring seemed odd to me and I think I have it hooked up wrong now.

Here’s a pic of my old one.