I started with the wire closest to radiator, pulled it and motor rand really bad. This happened to each plug wire pulled until I reached the rear spark plug wire. I pulled it and it stayed at same rpm and semi rough idle. All the others created a really rough idle that would almost cause a stall.
Seems like the cylinder is bad..... Plug is getting spark... Replaced spark plugs and had same issue... Turned motor off, put old spark plug in wire, fired up truck and there's spark to the plug.
So I pulled the spark plug wire from the spark plug closest to firewall while truck was running and it stayed running the same.... Must be spark plug cause wire seemed ok.
I've owned it for 4 months now. Since then the overdrive went out.... Kinda comes and goes. I've looked under the hood and see no obvious issues with vacuum lines cracking, or off. The last tune up on truck is unknown..... I'm gonna check spark plug wires right now.
My 1990 4runner is running super rough and has no acceleration. It starts and idles rough. When driving it shakes really bad like its missing..... What could be the problem. It also won't shift into over drive no more.... Frustrating cause I love this little truck!