FINALLY GOT MY 86 RUNNING.

[KatahGii]

Ok for those that have seen my posts I officially got my 86 running. After replacing the fuel sending unit, pump filter and tank. I replaced the crank sensor and then the fuel pump relay. I finally got it running. Ok new question it’s still not road worthy so still got some kinks to work out. I need to jump it for it to start but after it’s fine. Oddly my multimeter’s battery load test says it’s fine. But if I shut it off I need to jump it. Is that gonna be the alternator?

[Dzimm]

What's the voltage on the battery with the engine running?  If it's 14+V your alternator is fine.  

[Pete M]

the auto parts stores will run a more thorough check of the batter for free.  

 

also be sure to clean the connection between the cables and the terminals. 

[JMO413]

Old school trick to test the alternator. Start the truck disconnect the battery if it stays running the alternator is charging.

I would also check the ground cable to the block and all the connections at the starter are clean. Resistance is the Renix systems kryptonite.

[KatahGii]

2 hours ago, Dzimm said:

What's the voltage on the battery with the engine running?  If it's 14+V your alternator is fine.  

It reads at 13.5-13.7 when running. I think I might just have a bad battery.

[87Chief]

I would say a bad battery. What's the battery voltage after the engine is shut off for 10 minutes?

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[AMC86Kid]

Keep in mind the 86 doesn’t have a real alternator it’s just a simple 2 wire charger 

so it’s very common that your battery goes bad and you have to change it depending on how much you drive and what weather cycles it goes threw 

[KatahGii]

47 minutes ago, AMC86Kid said:

Keep in mind the 86 doesn’t have a real alternator it’s just a simple 2 wire charger 

so it’s very common that your battery goes bad and you have to change it depending on how much you drive and what weather cycles it goes threw 

It’s been sitting for like 4 months while I found the time to fix it. I’ve tried to start it so many times. I'm thinking about charging the battery outside the truck. Can I throw a regular alternator in it? 

[AMC86Kid]

Yes you can put a real alternator in it 

but you got to modify it to fit where the old one was and you have to add new wiring to accommodate the new alternator 

 

in other words its not just an easy swap since you can’t use the old plug from the old alt on a new alt 

[Green Mesa XJ]

For no start: One of the issues can be bad battery cables, when I first got my old 2.8 xj the battery and battery cables were crap. Replaced the battery to have a random no start but have plenty of power. If it was running the weak @$$ alternator kept up with the power needs. Replaced all the cables and it got power to the starter just fine. Still fine after all these years.

For the 2.8 one of the upgrades using the original set up was alternators off a Pontiac with the same clocking. It ups the amp from 55 to something better, I can’t remember which alternator I got now. Since the 2.5 and 4.0 use similar alternator it could be a possibility. Of course there a kits to add much better gm alternators


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[AMC86Kid]

the 2.8 has an alt thats around 70 amps 

the 3.4 alt is around 100 amps