I have a '95 4Runner that I have had the engine completely rebuilt on, V-6 3.0 and I just got it back last week and have one issue. It seems that the rebuild fixed my problems because I had two burn't valves, but now that I have it back the engine surges especially when cold, and I don't have any high idle when cold.

It happens most at about 2000 rpm not pulling hard just going down the road. I notice the tach occilating about 300 rpm with my foot steady on the peddle, but if I accelerate it pulls just fine.

I am taking it back to the shop because it didn't do this when I took it in, there was just a solid miss because of the valves. Any input that would help them find out what they did or didn't do would really help.

Thanks in advance

 

does it do it at an idle or on acceleration? if its at an idle it could be due to low coolant, or on accel. it could be plug wires.