I have a 4y that has @180psi in all cylinders. Turns over fine until you turn on the fuel and than it act like it hydro locks. We have 2 trucks a this facility and have swapped distributors, changed plugs, checked timing numerous times, and have pulled intake and exhaust. Nothing seems to change it. The symptoms stay the same and the other truck is running fine with this trucks parts. Any suggestions would be appreciated.
Thanks
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I've rebuilt a few 4Y's, and as I remember the cam/crank is gear to gear. Maybe there is some type of sloppy play that is exsibated on power stroke between the gears. Will be interesting to find out.
We were thinking a spark timing issue, but when we check the timing it is dead on. The customer is sending the truck to our shop. I will post when I find out the problem.
I would disable the spark and try it. If it doesn't do it then it has to be sparking at the wrong time (timing or firing order)
It sure sounds like an internal (cam and crank) timing issue to me. When you figure it out, post it so we know.
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