i just bought a 90 civic Si for $600. it is not running and i think it has to do with timing. it is getting spark and fuel, but no compression. looks to be that the timing belt tensioner spring broke and the belt slipped a few teeth on the cam gear. is this possible? also the stock motor is supposed to be a d16a6? i think. and the motor is just stamped "ZC". i know the motor was changed but it this the wrong motor. the guy before me had it running for about 3 months. one more ?. is the head an interference or non interference with the pistons. thank you for your time and help.

 

It's interference.

Did you get the SOHC or DOHC.

Either way the ZC is better than the D16A6.

 

its a sohc, thanks for the help, also, the motor has no compression, so how do i take the crank pully off if it just spins?

 

The crank pulley bolt has over 100#lbs of torque so it is a tough one to get off.

If you are not using an air gun, lift the car and there is a black plate that bolts to the bottom of the transmission at the point it bolts to the block. Take this plate off and you will expose the flywheel. A flat head screw driver carefully placed between the teeth should hold it still so you can get some force on the bolt.

If it doesn't break loose at first, heat it with a propane torch. If it still doesn't budge, try an impact screw driver with a socket holder in it.

Keep at it. That can be one tough bolt to get out.

 

thanks for the help. i will try that

 

id say if your not getting any compression than you have more of an issue than just timing....id say pull the head and start looking for bent valves.

 

While you do probably have bent valves, the no compression is probably due to the timing belt being off.

 

hmmmm i didnt know the timing belt was already off...in that case beta13 you are correct it would make the engine feel as if there was no compression by turing the crank pulley by hand.

Turbo-SIR if I were you i would fix that spring and belt and time it all up then turn the crank and see if there are any bent valves....you will know if when you cant turn the crank and it feels like something is in the way. If no bent valves then i would do a compression test on the motor and go from there.