ok, so heres my story, i have a 91 pickup with the 4zd1 in it. i was driving home and the timing belt broke, stripped 10 or 15 cogs off the belt. come to find out it bent all the valves. well before i had the valve job done on the head, i just put a new belt on and it fired right up and ran for a while, so i shut it off and went about putting my tools up thinking i was. not the case. bc then it wouldnt start back up. since then ive put new belt tensioner on and had had all new valves guides and springs installed in the head. got it all back together and still wont run. number 4 cyl is at tdc and everything is lined up and adjusted. i ran a compression check on all cylinders. 1 2 and 3 have 150 psi and number 4 has 0. that being said as this is my first time working with a isuzu motor, the motor should run off the other 3 cylinders just not run great correct? also if this is the case is there anyway to pull the pistons with the motor still in the truck? as i do not have the means to pull the motor. any advice, tips tricks or pointers will be greatly appreciated. thanks yall.