So today i helped my neighbor finish getting his newly rebuilt engine ready to start and want to know what i should do. A friend told me to take the distributor out and spin the oil pump shaft to prime the oil, then another friend said i have to have a dummy distributor in there with no gear so the oil flows through the jackets properly. which would be a huge pain with the engine in, it was hard enough to set the distributor properly with it out.

I know everything was heavily lubed during installation so is pulling the distributor really necessary? or can i just pull the coil wire and fuel pump fuse and crank it a few times to prime the oil pump then start it?

 

I wouldnt worry about priming the pump with the dis out,if its roller, Just kill the ignition and turn her over so it can build pressure.

 

Good luck and let us know how it goes

 

You can rent a engine priming tool @Autozone or get you and old salage distrubitor and make one.BTW I have always pre primed any engine I have ever rebuilt.Thats how I was taught ,with as much $ and time you have invested It seems like a good thing to do.

 

Oh yeah i forgot to add its a 4.3 in his 98 jimmy.


We want to do that but we also dont want to mess up the timing and damage the engine in that way when we go to start it.

 

You not going to mess up the timing.The distributor will only go in 2 ways.Either 180* off or going like how its supposed to with the rotor lining up with the number 1 cylinder.

 

You have to pull the distrubutor shaft out to turn the oil pump shaft right? or is there another way? If you have to pull the shaft then you have to make sure you get the teeth right. Unless im thinking of it wrong

 

When you pull your dis out lookmdown the hole with a flash light and look where the slot is at the end of the oil pump shaft.After you get done priming the engine you can turn the shaft with long straight screw driver then put your distributor back in.

 

You might as well just suggest cranking the engine up. The whole point of priming the system is to get everything lubed before its spun over. Assembly lube is to protect machined surfaces while putting it together. Its supposed to break down in the real oil when that hits it and be gone at the 500 mile 1st oil change.

The priming tool for a 4.3 is the same as a 350 or 305 (any gen one small block chevy) and you know how common those are. Any good parts store should rent ya one. My 90 degree I bought but my 60 degree (2.8/3.4) I made as described out of an old dizzy. Always prime your engine before its turned over the first time. I even prime them if they have been sitting for a long time if I'm gonna try to crank it.

 

I would absolutely prime the engine. I use a screwdriver with a slipjoint over the pump shaft and a drill. I spin it up untill I get a good reading on a mechanical guage plumbed into the oil pressure sending unit orifice. I have never had any issues doing it this way on 4, 6, or 8 cylinder engines. Stock or performance built.