I have a 1990 4Runner with a rebuilt engine. I was paranoid about mechanical timing, so I tested it over and over and I'm certain it is good. It doesn't kick back or backfire when I do actually get it to start for the few seconds it runs.

I have reconditioned fuel injectors in it.
I have tested the EFI relay and the EFI fuse.
The noid light flashes.
I tested fuel flow, but not fuel pressure.
I have new spark plug wires, cap and rotor with Bosch platinum plugs.
New battery, new starter.
I tested the spark and it seems fine.

It will start and run for a mere 3 seconds. I can stretch it out a little bit if I spray starting fluid down the hole.

I have no more ideas of my own.

Any ideas would be helpful and very much appreciated.

 

Volume Air Flow Meter.

Check it per the FSM specs. You just described how it tries to start if it's disconnected or went bad. Don't replace just yet, just grab an ohm meter and measure the resistance as directed.

 

I had hoped this would be a "kick-myself-it-was-too-darn-simple" problem. I had the air induction hoses off it so I could have easier access to the distributor bolt for timing it.

I connected the hoses and it started right up.

The upside is that I have some new parts that I probably didn't need in order to make it run, but now I have them it is good I do.

Thank you.

 

Haha, no worries! Happens to all of us.

The only reason why I knew it was air related it because I forgot the plug my VAFM back in when I was working on it recently. Been there, done that.