So I haven’t been honest with you guys and it’s time to come clean. This summer I was driving the 4Runner to get groceries with the kids when on our way home blue smoke started pouring out of the exhaust. Fortunately I was less than a mile from home. When I got home I parked and started to try to figure out what it could be. After tearing it apart I found that somehow the pre-combustion chamber in cylinder 3 had come loose and was just floating in between the head and the top of the cylinder. I also found a crack between the number2 and 3 cylinder sleeves. So I bought a new AMC cylinder head and epoxied the crack. Once the epoxy had cured I surfaced the top of the block using a 24 x 12 granite tile with sandpaper glued to it stepping down in grit until the blue indicator fluid was sanding away uniformly. Once this was all done I put everything back together with a new set of injectors and glow plugs. So at this point the whole top end was new. I re-shimmed the valves and attempted to start it. I was not getting anything to happen though. I tested compression and every cylinder was in excellent condition with my lowest cylinder being at 420 psi. I could get it to pop and run for a short period with some ether but couldn’t get it to sustain. At this point I was calling everyone for ideas and couldn’t get anything to work. So I threw in the towel and called a retired diesel mechanic who was willing and excited to take on my project. So I had it towed over to his place. Within a few hours of working on it he had it running. I had made a real bone head mistake and had installed the fuel pump sprocket 180° out of timing which had broken the hub where it interfered with the pin. If I had installed it 90° out it would have bent all the valves and likely damaged the pistons. Later he found that it was leaking coolant from cylinder 4. He has taken it apart and has found another crack between cylinder 3 and 4. He is in the process of getting everything back together and found some grit in some of the head bolt holes that was preventing full torque. Fortunately Toyota still had new fuel pump sprockets available in Japan for only $20. So no real harm was done. I have installed a 165° thermostat which I hope will prevent the problem from happening again. She should hopefully be back on the road again and I can resume my projects on her.
