so if I follow exactly what you're doing but leave my OMP in for the time being is it okay? Just premix with a smaller volume of 2 stroke?

 

I have a 93 FD that just recently threw the CEL for OMP failure.

My car is relatively stock with only intake, exhaust, & downpipe. It has the stock CPU as well.

What are my options for premixing?

If I get the bansai block off kit do I need to buy a Power FC to not stay in limp home mode? Or can I stay on the stock CPU?

I did read through most of the thread, but there isn't anything on what to do with a failed OMP

Any help is greatly appreciated

 

You have a couple options. You can buy a good used omp and just plug it into the connector by the oil filler neck and tie it out of the way and that will get you out of limp mode and you can premix.

You can install it correctly which is what I recommend, it is only a couple hour job at best.

You can buy a PFC and just premix and the PFC will not go into limp mode.

My opinion is put in a good OMP and premix on top of that. Thats what I do but do as you feel.

 

even though this is a 3rd gen topic... the title and author caught my attention...

good read...

i bet any money though, that both my rotors look exactly like those carbon caked rotors....

 

I've seen first hand comparisons of Amsoil Interceptor with other oils in two stroke applications, the power valves and piston crowns with Interceptor are night and day.

You don't need the OMP, it's a liability. Keep everything simple with car. I've pre-mixed at 1/2 oz/gallon for 4-5 years, and compression is excellent (15 psi boost runs every time I drive the car). Pre-mixing takes 10 seconds - tops - at the pump. Fill the tank half full, pour in 8 oz, top off the tank. It doesn't get any simpler, and it's 100% failsafe.

 

anyone have a good recommendation on an alcohol compatible pre-mix?

 

So after going through 5 pages of this thread I havn't seen one comment regarding a carburated motor. I'm running a street ported 12a w a 400 holley (84 FB) with the 2 hoses that squirt oil into the primaries. I'm interested in going the premix route but not sure if the same rules apply to me being I'm runnin' a carb.
What route can I take to eleminate the omp, I know theres a link I have stuck in a bracket hole that keeps it 3/4 open @ all times. Can I just disconnect that linkage and begin premixing?? Any & all advise is appreciated, Peace.

 

it's a 12A

they last forever and the OMP rarely fails...

 

So to get all this right once and for all I want to throw this out and get a bless off before I do it, mind you I really DO daily drive my FD and I''m currently @ work reading this thread so:

I'm sold on Premix, during lunch break I'm going to go buy some 2-cycle oil, then i'm going to the gas station, I'm going to pour in the 2 cycle oil into the tank and pop the hood and reach down and UNPLUG my EOP (I have a PFC by the way). Is this ok? I plan on going with the 1oz/gal since I'm running single turbo, walbro and all that Jazz. But I'm wondering as far as there being some problem with leaving the EOP AS IS and just unplugged and just pre-mixing. Thank you and BTW Great post as always HC.

 

My issue is not of the OMP failure, it's more of a carbon build up concern....

 

yes you can, no there's no problem, just remove it all when you get a chance, it removes some lines and the OMP from the engine bay, cleans it up a bit.

 

^^^ Thanks KKM for the quick response, I guess I'll go now even though it is past lunch...lol BTW I can't wait for my injectors... Thanks again!

 

Just a thought we can buy the Banzai block off plate and drill a hole like the plate above & tap the OMP to pull from a resevoir.. Or maybe Banzai can offer this lol hint hint...

 

^ Thats ingenuity. I want to know more about that system and how it is working out. However, if the OMP works off of the engines oil pressure then how is this going to work?

 

Install a water injection kit. Snow performance makes them for N/A vehicles. Some of the other manufacturers might make them for N/A as well.

 

The oil pressure only fills a small cavity on the OMP face then spills any excess back into the engine's pan.

The only problem we have seen is that the shaft itself, if it is wore, can leak it's 2-stroke oil back into the engine. One engine we have done does this intermittently.

Barry

 

awesome thread... very helpful

 

I made my 2 stroke setup and wonder why my half gallon jug would be empty if i left my car sit for 2 days... shaft worn out

 

I'm the one Barry mentioned losing 2-stroke back thru the shaft. On the first attempt, I was losing oil back to the pan when it sat in the garage. That was fixed by getting a good seal on the oil relief passage. It is my belief that Barry and Chuck Westbrook, who's also using this block off plate method, got a better seal on their first attempt. Barry's usage seems normal while I have not talked with Chuck about it in a while but with only a little bit of driving his seemed OK.

Jonathan (Gorilla RE) and I setup an experiment on the bench as shown to see where the oil was going. After 2 weeks setup on the table as it sits in the car, no oil loss. The pictures show the block off plate when we pulled it off the test and the red circle shows a nice ball of silicone where the oil relief is. Our assumption is that we didn't get a good seal the first time install. For longivety sake, Jonathan filled in the oil relief port circled in orange with JB Weld.

With about 1,000 miles now and periods of sitting in the garage 2 weeks at a time, I have no loss except when running. I've used almost 2 quarts and see a noticable drop in oil level on trips as short as 50 miles. Driving Rx-7's for over 25 years, I've never had too add more than half a quart of oil between 1,500 to 3,000 mile oil changes for OMP use - mind you this is street driving.

The shaft has no seal back to where there is oil inside the pump. After hurricane season, I'll be taking it apart again after checking our inventory OMP's for the shaft with tighest fit around the insert and try to find a fresh oring for the insert.

Jack

 

well hell. after reading this you have my gears turning. my fresh motors about to be together and i was going to try the 2 stroke injection again. I guess im going to rebuild my pump. Try to find orings that fits very snug. what did you do to your front cover to accept the 2 stroke injection? I see your on a s5 pump im on a s4 mechanical

 

No modifications were done to the front cover.

The OMP does not rely on engine oil pressure. Contrary to popular opinion, it creates suction.

Jack

 

https://www.rx7club.com/showthread.p...hlight=diy+mop

patmans write up he modds it

 

Yep, that's where we got the idea. A rotary aviation adapter won't fit with my turbo manifold so I started searching alternatives.

If you follow that thread plus some others that have used this method, not everyone follows the same method. We studied the inside of an REW front cover and decided nothing needed mods there.

Jack

 

Is pre-mixing really that tough? I don't understand throwing a bunch of contraptions at something that takes an extra 10 seconds at the pump, and you know it's done right.

Racing two stroke MX bikes and waverunners all pre-mix, there's a reason for that

 

Yeah man why don't you go ahead and take off you starter and just weld a hand-crank on your main pulley so you can have a harder time performing a task that has been simplified for you?? Mazda provided the method and the tool, the tool just pulls the wrong oil from the wrong place, some of us would like to fix that and move on with our lives and not have to carry measuring cups and quarts of oil that bang around in the trunk as you pull crazy G's racing. The oil may spill while the car sits at work in the parking lot and now you go to pump gas and "oh snap not only do I have the BP oil spill going on in my trunk, I also don't have any two cycle oil" Now I need a new rear carpet too. I can go on.... Bottom line... some of us are just lazy ok? Can you respect that? Oh yeah go ahead make some more analogies about how rotary engines are exactly like 2-cycle engines...so everyone can keep laughing, I know I am...lol