Need some insight on my rough running 4runner. Runs terrible, no power almost, and is so bad it will stall often. Hardly revs at all too, the exhaust stinks. New plugs and wires, I know it’s not the distributor cap, it’s in good condition. But I can unplug 3 plugs from the cap while it’s running and nothing happens to the way it runs, only 2 of them affect the way it runs and there is definite power going to it because it will even jump spark from the plug to the cap when close enough. Also there is almost no vacuum from the EGR valve vacuum hose. I checked other hoses and some have vacuum some don’t. The EGR one actually had a little bit of pressure towards it instead of vacuum. At first I thought the problem was fuel related because you could have your foot on the floor and the rpms wouldn’t even rise it just sounded like it was bogging. Tried reading the codes but it wouldn’t work, I’ve had check engine light on once or twice not too long ago but it’s gone now. And the idle is very sporadic, might be still bad but a little better one day, terrible the next. Just would like some ideas, thanks!

 

Run a compression test.. You've likely got expensive issues.

 

x2 ^^

When you say the exhaust stinks, does it smell like raw fuel?

What did the spark plugs looked like when you replaced them? Normal?

 

 

Rarely do I say it probably just needs a tune up but that's what I'm gunna say it might need in this case. Start with a compression test and spark test before spending money. Its a waste to spend a bunch of money on something unrelated to an engine that makes only 50 psi. If the compression checks good then look into replacing plugs, wires, cap, and rotor. Just because it might look ok doesn't mean it is. Its hard to see failed components on the inside of a part. Also, if its been sitting that long then get get that old gas out of it and get some fresh stuff in it. Gas doesn't last as long as it used to. I once had a can with gas about a year old that couldn't even be ignited with a flame. If that doesn't help then you will want to look into the fuel delivery. Fuel injectors will cause cylinder specific misfires. A weak fuel pump and dirty filter will cause random misfires.