Just curious, I would hate to know ive been doing irreversable damage to my engine just from not checking it.... how do i check the omp in my 79 rx7? All stock 12a engine.... let me know. Thanks.

 

Look inside the carburator, rev it with your hand and look inside the primaries. You're going to see 2 little copper lines on the primaries. They should be dropping oil in.

 

There's also a method to measure the flow/discharge from the OMP. It's on page 61/62 of the Haynes manual (and probably somewhere in the FSM as well).

I'd be fine just knowing it's working though (although I'm pretty easy on the car, don't race, etc), and JoeyMazda's method should work just fine for that.

 

Im sorta of nervous about this because i cant see any oil being dripped. I see for sure where its supposed to be dripping. I have been working hard on the car for a while, probably only put 10 miles on it, but it has quite a few idle hours on it... and some pretty hard revving on it a few times, and i was worried because i havent noticed a change in the oil level on the dip stick... I guess its time to premix.... or something. How hard is it to change the pump? Where can i find a new pump? Is that the only factor there can be in it getting oil? I dont believe that it is working... i also dont believe i have caused any serious damage, the car seems to be running verrry strong and such. No weird noises etc.

 

From the 85 FSM. 79 is almost identical. Output should be slightly higher on the SA models. 80 FSM says 2.0-2.5 cc/6 min.

 

CC's..... that would be like a very very little amount over 6 minutes right? as in the same as what 2.5 cc's would be in a syringe over 6 minutes? I probably didnt even notice a little drip like that...

 

My car has only ever burned alot of oil once, and that was at the last autocross I went to where everytime I redlined it and came off the throttle a big puff of oil smoke would come out the tailpipe. The OMP does not use a whole lot and if your doing regular oil changes you probably won't notice much if any of a drop in oil level. Another way you could check is use a small piece of clean white rag or paper towel, and hold it in front of the oil lines inside the primaries and rev the **** out of it. If it comes out with oil on it, your fine, if it's clean then it's premix time.

 

KC - just rebuild yours. Very easy - pineappleracing.com sells a rebuild kit (just a series of O-rings) and includes (!) a neat DVD tutorial on how to do it. No special tools. $25 if memory serves. And the pump is held in place by 2 -10mm bolts. Just be sure to note WHERE THE PUMP ROD ATTACHES: what position the rod connection is in, because there are a couple of choices IIRC. oh, and you'll need an OMP-to-cover gasket from mazda I think, because I don't believe the pineapple kit includes this (could be wrong)...

And- might be time to replace decades-old oil LINES?? Splurge on the Old Girl and get new ones...

Stu Aull
80GS
Alaska

 

Yes, it's a very small amount. A cc (cubic centimeter) is a volume 1 centimeter on a side... also known as a mL (milliliter).

For comparison, a normal "full size" shot glass holds 45 cc (1.5oz). So we're talking around 1/20th of a shot, in 6 minutes.

 

yep its a surprisingly small amount