Bronco won't stay alive

[Nelson and Hudson]

1987 Ford Bronco II 2.9L V6 Auto

replaced: Fuel filter, oil filter, new oil, alternator, starter relay to starter cable, ignition coil + connector, distributor and cap, wires, ignition switch, plugs gapped, new battery, cleaned the IAC, cleaned and inspected TPS, replaced throttle body gasket

Hello this is a new issue I'm trying to fix I start up the Bronco it'll run for 30 seconds decent idle and then randomly die.

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I'm not sure what to do or where to go from here.
Any advice would be appreciated.

 

[gaz]

@Nelson and Hudson ,
Why are starting another thread about the same issue?

 

[Nelson and Hudson]

@Nelson and Hudson ,
Why are starting another thread about the same issue?

Because this is a different issue. This hasn't happened before. I've never had it where it couldn't run for longer than a minute.

 

[BroncLander]

Could be-
-Plugged fuel filter
-Clogged air filter
-Vacuum line broken, missing or off
-vacuum advance weights corroded & stuck
-faulty sensor (map, maf, 0², ect)
-heck maybe your gas cap isn't on tight/vapor lock

 

[alwaysFlOoReD]

Borrow, rent, or buy a fuel pressure tester.

 

[Josh B]

Borrow, rent, or buy a fuel pressure tester.

Just realize borrowing and renting may get you faulty readings at twice the price

 

[BroncLander]

Borrow, rent, or buy a fuel pressure tester.

Oor just get an inline fuel pressure gauge for constant readings into eternity and beyond

 

[Nelson and Hudson]

-Plugged fuel filter : Replaced recently
-Clogged air filter : Blasted that out with air. Also wouldn't cause it to run for 30s then die abruptly
-Vacuum line broken, missing or off : Maybe? Again, I'm pretty sure everything is on and working
-vacuum advance weights corroded & stuck : Maybe? How would I check?
-faulty sensor (map, maf, 0², etc) : ^^^
-heck maybe your gas cap isn't on tight/vapor lock : Definitely not, broke a gas cap recently so ever since I've been extra careful to put it on properly

 

[Nelson and Hudson]

Oor just get an inline fuel pressure gauge for constant readings into eternity and beyond

I don't even know how to do that lmao. I tried to get a fuel pressure tester from O'Riellys and it didn't fit my fuel rail thread.

 

[BroncLander]

Just get an appropriate gauge and fittings kit, and it goes along the fuel line somewhere in the engine bay. You'll have fairly accurate fuel pressure readings all the time. They're cheap

 

[Josh B]

Could it be prone to leaks?
What kind of line is best?
Does it only need one line from the fitting to the gauge?

 

[BroncLander]

Could it be prone to leaks?
What kind of line is best?
Does it only need one line from the fitting to the gauge?

Just use whatever is recommended. Never use teflon tape for fuel systems because it melts

 

[Nelson and Hudson]

@BroncLander I just reset the base idle to where it should be at 700 rpm with the IAC unplugged. But as soon as I plug that IAC, my idle goes all over the place and it does in a few minutes. Does this mean my IAC is bad?

 

[alwaysFlOoReD]

@BroncLander I just reset the base idle to where it should be at 700 rpm with the IAC unplugged. But as soon as I plug that IAC, my idle goes all over the place and it does in a few minutes. Does this mean my IAC is bad?

Afaik, unplugging the iac should bring idle down to 500 or even kill the engine. Sounds to me like you have a vacuum leak.

 

[Nelson and Hudson]

Afaik, unplugging the iac should bring idle down to 500 or even kill the engine. Sounds to me like you have a vacuum leak.

I'm not sure it's a vacuum leak. After I reset the ECM by taking off the cables for a while. After reconnecting the B2 will run for a good few minutes before intermittently dying. Seems to be out of the blue with no warning. Does this imply a vacuum leak? What other tests can I do to confirm whether or not it's an electrical issue. It idles great now, even with the IAC connected, but it will just abruptly die. Doesn't matter if it's warm or cold.