Hi guys, I just dropped in a newly overhauled 4.0 in my 91 YJ and I have some questions. I spun the engine over with the starter, with no fuel to it to build up oil pressure but it will not build up pressure. I pulled the oil filter and no oil was even up to the filter. I checked the distribitor for proper oil pump engagement and I made sure the pump was turning with the distribitor. I personally installed the pump and pickup tube with a new gaskit between the pump and block. I didn't have my oil pump adaptor to spin the pump with a drill so I'm hoping the starter is just not fast enough to pull oil in a dry pump. I will remember to take my adaptor to spin it with a drill when I get back to the shop I'm working out of. Any ideas would be a big help; I'm tired and just not thinking clear at this time. I also noticed that the distribitor was not sending spark to the spark plugs. However the coil wire would fire a spark plug which makes me think the crank sensor is ok. Correct me if Im wrong; no oil pressure in a jeep cuts out spark to the plugs? or is it no oil pressure in a jeep cuts fuel pressure from the pump?

John you can do what I do... I beat the handle off of a large screwdriver and put it in my drill.. It works fine. You must be careful to get #1 where it goes..
Big Jim <img src="/forums/images/graemlins/pfft.gif" alt="" />

If the coil is firing but you are not getting spark to the plugs, then your wires are bad or your cap and rotor is bad. Once the coil fires there is no way for the computer to switch off the spark.

Priming the oil system should be done with a drill. I know a couple of people who do not prime their oil system, instead they use a lot of lithium on all the bearings. When they fire their motors it takes a good 4-10 seconds @ 2500 RPM for the engine to stop clattering and oil pressure to be available. Cranking it will work, but you'll kill the battery before you get any pressure.

Thanks guys, I'm off to finish it with a good nights rest and a clear head.

I got the oil pump primed with my drill and fixed the no spark problem by restabbing the distributor; I had it one tooth out. It perrs like a kitten and in the process of changing the engine I fixed my mystery rattle that had haunted me for 6 months; it turned out to be the drivers side motor mount bad. Thx again guys.......

<img src="/forums/images/graemlins/kewl.gif" alt="" /> Happy birthday! <img src="/forums/images/graemlins/cheers.gif" alt="" />

LOL.........thanks.