choppe777

FYI- my 94 22re runner is having major idle troubles and stallls out when stopped or idling (while driving, it went from great to bad instantly...idle dropped to nothing and stalls at stops and runs rough). No check engine light came on either.

While doing some stuff to fix the above problem (which isn't fixed after a basic tune up) I turned the key in ignition without starting the truck and I heard a buzzing noise. It sounds like the fuel pump is running and it also sounds like a hissing is coming from behind the engine. It's weird. Should this be happening?? What is it??

Thanks for the help...

wrenchmonster

Do you smell fuel? The pump should run for a few seconds to build pressure in the line, but that's it. Check your fuel pump relay too, as that could get stuck.

choppe777

The pump in the gas tank keeps running and doesn't stop. There doesn't appear to be any gas leaking anywhere, but I can feel pressure surging the fuel lines. I don't know if it's deadheading somewhere or flooding the engine.
I'll check the relay...

84sr5yoty

I think I've answered your question in another post, but I’ll answer it here too.

The AFM (air flow meter) cycles the fuel pump on while cranking and running only. The fuel pump will NOT come on with the ignition on like modern day cars and trucks. If the fuel pump is running with the ignition switch on, then either you have the fuel pump test connector shorted or the AFM is stuck open or not operating correctly.

Check the flapper in the AFM to make sure it moves smoothly and that it's not hanging up. Also, ohm the AFM out. I think there is a post somewhere that gives the specs for 89-95 22re models.

choppe777

84sr5yoty... you were dead on... The AFM was shot. It was replaced and the truck is back in operation! Thanks for the posts.

84sr5yoty

Glad I could help