Hey guys, first post so please be kind. Okay, I bought a 92 4runner 3.0 4wd that had supposed bad head gaskets, changed the intake manifold gaskets and that stopped the leak the previous owner had suspected to be head gaskets. Tried starting it for the first time and it had no fuel to the fuel rail, no fuel pump sounds. Come to find out, EFI relay had been taken out for some reason. Replaced the relay and still no fuel. If I jump it from the diagnostic box, the fuel pump runs fine, but won't come on by turning the key on. Relay still clicks, all fuses are good. What am I missing here guys?

Justin

 

Check this thread for clues:
https://www.yotatech.com/forums/f116...l-pump-248683/

I was thinking it may be the VAFM cutout switch or something, but the thread gives more info.

 

The VAFM internals look new, no problems seem to be had there, scratching my head still as to what I'm missing. All fuses and relays are good, pump is good...any advice on what my next step should be? Thanks for the help!

Justin

 

From the electrical diagram, when you jump the diagnostic connector for the fuel pump, it will turn on, even if there is a different problem with vafm/circuit opening relay. Another input that needs to be energized for the COR to be on is power from the park/neutral switch for an automatic tranny or power from the starter relay for a manual tranny.

I hope this helps you some.

 

Just to clarify, the fuel pump won't come on with the key at the "on" position unless the engine is running to activate the VAFM switch. It should come on when the key is turned to "start", but may be hard to hear over the noise of the starter.

Will the truck start with the fuel pump jumped at the diagnostics connector? No harm in testing it out that way, but not a good idea to run that way long term.

Could be the circuit opening relay. That has to work for the fuel pump to come on normally (i.e., without jumpering the diag connector)