So i have a 98 cherokee sport and the oil pressure guage stays on 0 till im have the pedal on the floor in 2nd and 3rd gear then it reads about 30 is that a bad sending unit? Or should i plan on doing injectors?

 

Hook a direct pressure gauge and see what it reads.

 

well i can say i had around the same problem. mine ended up being that the oil pump body was broke where the small bolt, bolts in to the bottom of the block. but also check to see if your oil pressure sensor is not broke/cracked or just working at all. but you can check with a oil pressure tester gauge. they have them cheap ones at harbor freight. thats where i got mine i think it was $20.

 

Hmmmm I don't think fuel injectors will help you with oil pressure but you could try replacing the oil pressure sensor.

 

also check to make sure that the hole where the sensor screws into isn't plugged with gunk, I have had this happen in the past. I ran a manual line from the hole and rev'd the engine and it blew out a few chunks, then the oil pres gauge read correctly.