New issues with ‘85 - electrical?

I’ve had my 85 4runner for about a year after buying it from a friend who had it the previous 3 and just started having some issues that seem connected. Hoping the forum can help find what my mechanic can’t.

After driving well all morning about 5 weeks ago it started sputtering while going up a hill until it died. No power to the fuel pump. If power was applied directly to the fuel pump it would start. Put in a used fuel pump and new fuel filter. Stil nothing. New main relay and fuel pump relay, still wouldn’t start. Mechanic cleaned a bunch of connections and it started (though they couldn’t telll me what went wrong or exactly why it started working) - ran for a week than stopped. Drove to work but when I tried to go to lunch it would turn over but not start. Mechanic put in a new fuel pump and battery (it was 6 years old but seemed mostly fine) and it worked for the past two weeks. Yesterday while driving home the alternator went out. Could there be an electrical issue underlying these problems happening one after another?

 

Alternator itself might have been creating some low voltage issues... did you ever check battery voltage?
Sometimes it's just one thing after another with the trucks till you get ahead of the issues... sounds like your eliminating other possible failure points and on the right track...
I fought mine for a LONG time over the fuel pressure regulator, intermittent start, and vacuum leaks...
Bad wiring/ shorts and ground issue are very common...

 

Battery voltage seemed good the entire time even though it was pretty old. Putting in a new battery was essentially hoping it’d fix it.

I can’t totally afford to have a mechanic spend 25+ hours rewiring the truck, but are there things I can do on my own? Should I start digging into the wiring to get ahead of any issues?

 

Check voltage with a multimeter...
Don't assume it's ok or think, or it seemed ok... you need to know your voltage from the alternator and your battery are healthy...

 

The original battery tested at around 60%, which seemed sufficient to supply power to the fuel pump. Though it has a new battery now. It’ll also have a new alternator this afternoon, which should fix the immediate issue. Just hoping to get a jump on things if these symptoms could be from a wiring issue or something else that my mechanic could be missing.

 

New battery, new alternator...
Verify they are doing their jobs...
Then if your still having issues report the best you can what it's doing or not doing...

 

Thanks for the help. Hoping this’ll be the end of my issues for awhile.

 

New alternator and it fired right up. Said that the alternator smelled a little “burnt”, so maybe the original electrical issues let to it’s failure. Hopefully it’ll stay running. My wife’s already told me that our baby can’t ride in it until it is problem free for a month or so.

 

She isn’t pretty, but at least I had a chance to put her 4wd with the snow in Seattle today.

 

Beautiful...