New motor - no oil pressure!?!?!?!?!

[JGWalker2]

Hi:

I have a 1991 Jeep Cherokee Laredo 4.0L I6 with 63,000 miles on it. I bought it at an auction with problems described as "electrical problems". Turns out the CPS had been removed. When I replaced the CPS, the motor started fine, but ran rough with really bad blow-by. After I removed the pan, the bearings looked oil-starved.

I bought a remanufactured long block, and after I installed it, this motor has no oil pressure, either with the dash gauge or my mechanical gauge. I even removed the oil filter and there was no oil even in the filter! I got a new oil pump with the long block, so other than replacing the pump I am stumped on this one.

Please help, as I need to get this project out of my garage and move on to the next one.

[xj31]

was this motor completely put together or did you have to put the oil pump on?if you dont fill the oil pump with oil to prime it ,usually it cant pick up oil .other than that if the distributor isnt pushed down all the way it wont turn the oil pump.

[Cam7]

Dpop your oil pan and prime your oil pump with oil or vasaline, then take your oil filter and fill it with oil hopefully this will prime the system.

[gtmud]

I agree with Cam7, if the pump wasn't primed it won't work. You could either pour oil into the pump, or find something that you can attach to the pump drive and connect it to a drill through the distributor opening and spin the pump till there is pressure(oil flow). Also this works, take the pump, remove the bottom plate that covers the "gears". Using petrolium jelly pack the area around the gears, reinstall the cover, this will prime the pump and the jelly will harmlessly disapate throughout the oil. Hope this helps. I've done the drill priming numerious times, worked everytime. Also would recommend pre lubing the bearings before oyu try to spin the motor again or at least with the plugs out, crank the engine over with the starter and your mechanical guage hooked up, to know for sure you have pressure before you throw fire to it.