evilscorpion

I have finally purchased the jeep i have always wanted,however it was a project somebody else abandoned,an 87 cherokee 4x4/bone stock.the body is perfect shy one slightly damaged bumper end cap/the motor is clean and painted all plugs wires rotar and cap is new no leaks in trans or transfer case and all shift quite well.but it has had a severe misfire since purchase.
I have replaced the injectors,fuel pressure regulator.the timing and firing order is all correct .i keep hearing about a cps,and how it tells the injectors when to spray?could this be my problem? I have a manual, and i have experience with ford and gm but this has me stumped. Help!!