does anybody here have any knowledge about the mechanical metering pump on 86 NA's? I'm wondering if all four tubes should be injecting oil as soon as the engine is running, or if it's only two tubes until the engine is running faster?

 

As far as I know (which means I may be wrong), the two for the "secondary" intake manifold don't become active until the throttle is opened up, but from all the OMP gunk I had in my 5/6 port intakes & runners, they just might run all the time...The FSM test has you pull two, and check volume while engines rpm's are up, but I don't know which two they are. Didn't even answer your question, did I?

 

no, that's help and that's what I'm looking for. See I bought this car a while back and it has been neglected, so I'm going through it all. I just wonder about the pump because it is so important to the engine. When I first start the car, one line is full but the others slowly pulse oil up them making their way to the engine. I'm just trying to find out what their normal function is. thanks for your help by the way.

 

IIRC, they all run, at all times.

Also, the S4 OMPs are not particularly prone to failure.