Rough idle and knocks under load

[ScottAS]

I have a 2000 Ranger, 4.0L v6, that knocks when going up hills, or when accelerating. It is actually a little weird, even on the flat when going around 40 mph, if I accelerate just a little it shudders and hesitates. If I let off just a little it will smooth out. If I push harder on the gas then it will pass through the shuddering and accelerate. If I accelerate hard enough then it knocks. Sometimes when I first start it, it idles a little rough but then smooths out.

I have replaced the spark plugs (they needed replacing) and the wires (they probably didn't need replacing). Ran a little better after the new plugs, but still has this issue. I am not sure where to go from here. I have had to replace a couple of vacuum hoses in the past, but can't tell if I have a vacuum leak now. Those things are stinking hard to find. I've seen things saying this could be a bad EGR valve, but I can't actually figure out where it is. I bought the truck new in California, so I assume it has one. It is just not where any YouTube videos I find show it being.

I would appreciate any suggestions anyone might have.

 

[ScottAS]

Didn't say before, but I have no check engine light or codes.

 

[SenorNoob]

Just a thought, but what about fuel? What grade are you using? I know the early 4.0 didn't like 87 very much.

 

[ScottAS]

Just a thought, but what about fuel? What grade are you using? I know the early 4.0 didn't like 87 very much.

I usually run 87, but I do feed it mid-grade periodically. I haven't noticed a difference.

 

[PNWcossack]

Your EGR valve should on the drive side of the engine bay, there are two hoses that connect to it from the exhaust manifold, at least it is for my 97. perhap look up the part on rock auto and you can find it that way. I would check for vacuum leaks, while it is running, I would use carb cleaner around areas that are prone to leak, the idle will spike if there is a leak. I had similar issues with my rebuild, but in the end, I had a clogged catalytic convertor. The way I was able to test this was to temporarily remove the first O2 sensor.