Hi everyone, i am new to this forum and to working on cars in general. I purchased a 1993 4runner 3.0 v6 4x4 to turn into a budget overlander and to learn how to work on cars. It has been great except recently it started having this issue where it starts, idles super low and rough, then stalls. I can rev the engine but usually it dies after. So i had it towed to a shop (it left me stranded) and it all of a sudden started working okay again. The guys at the shop couldn't find anything wrong after all their tests. They threw out a guess which is the idle control valve is going bad or is intermittent. Has anyone else had this issue and where should i start in diagnosing and fixing it so i can get back on the trail? thanks!

 

Basic issues that can cause this include vacuum leaks, AFM malfunction, maybe distributor not being locked down? I've had this a bunch of times on mine, it can be caused by quite a few things. Usually for me it's something airflow related.

 

The distributor is okay, it recently got changed along with the cap, rotor, and wires. I haven't really had a chance to look into any air flow issues but i will this weekend. What solved the issue on yours?

 

I've done a bunch of different things over the years. I've had vacuum leaks that just need plugged. I've adjusted the main idle screw on the throttle body, it's a big fat flathead screw on the in the side of it near the top, turning it left usually makes it idle higher. I've replaced my AFM twice, the electronics can go bad and the flapper can get sticky.

 

I had a somewhat similar issue on my 91 3.0. Turns out timing was way off from the PO, set at 0° TDC. Set at 10 and it ran fine. I recently adjusted the dial in my AFM to run a little leaner, trying to see if I can get any more power and now I'm having the same issue again, idles low and rough and sometimes stalls. I'll be adjusting the AFM back to stock until I have a chance to mess with it a bit more

 

I just had the same problem starting my 94 after fixing a head gasket. Engine started right up and ran fine for about 3 minutes then stalled out. Ever since it would start and run for about 10-15 seconds then stutter out. I did find my fuel line from filter to front is bad and leaked pretty bad at the fitting. So once that comes in I'll see what the next thing is. Let me know if you figure it out. I'm thinking it's the AFM on mine. I need to test it.

 

Use the FSM to help with your trouble shooting. Helped me out not long ago. Good Luck.