engine surges at half a tank

[flatlandrunner]

I have a 92 4runner with the 3.0 234k on the clock

When the tank is full it runs good but as soon as I hit half a tank the check engine light comes on and it will start surging while going down the road with moderate throttle pressure. Sometimes its a 2-500 RPM jump. If I baby it it doesnt do it near as bad.

Any ideas? Fuel pump? TPS? Vacuum leak? havent really dug into it yet just looking for some info on what to check first.

 

[RedSled]

I would look at the fuel filter 1st.

 

[flatlandrunner]

I changed the fuel filter about 500 miles ago. Im not ruling that out tho

 

[DeclansDaddy]

Funny thing, I have the same problem with my '86 22re. It did it regularly when I first got the truck, then it seemed to go away, now it does it again. I'll be curious to see what you figure out. As soon as it warms up a little here I plan on looking into it more so if I figure out my problem I'll let you know my findings.

 

[bump530]

If it does it at half a tank, I would inspect the rubber hose inside the tank. It may have a hole in it.