RealityX7

I recently discovered that the previous owner of my car removed the oil metering pump as there is no block bolted to the side of the front housing. I've been running the car (fairly hard) for the past 5 months without premix ;(. should I be expecting any immediate engine damage?

Aaron Cake

iTrader: (1)

See, this is EXACTLY why I am against mods like premix for a daily driver. Sure, it may be fine for you, but what about the next owner?

Anyway, you probably did accelerate wear significantly. Either start premixing or restore the metering oil system to it's previous state and then run a compression test to make sure things are still OK.

RealityX7

I started premixing the tank after i found out... the car still runs like hell (in the good sense of the phrase) but idle and full boost just dont seem as healthy as when i got the car... could just be the placebo effect or maybe i damaged the motor.. that would suck only had 8k on it when i bought it, bout 10k now but we'll see what happens... i smell a rebuild coming on by the end of summer...

are_one

The previous owner of my NA cut the OMP lines (have no idea why?) After I made the discovery and fixed it, the rear apex went 1000 miles later. Total miles was 133K.

J-Rat

iTrader: (2)

Maybe the seller should be more aware of what he is selling.

prjct87rx7

iTrader: (7)

maybe some one should make a sticker for us to put over the premium fuel only one. to say premix fuel only...or i guess he coulda just told him when he sold it to him..lol

J-Rat

iTrader: (2)

Thats what I would have done, I would have just told the person.

ultrataco

iTrader: (2)

how difficult/expensive is it to get the car back to stock?
i'm looking at buying an fc, and I don't remember if the owner said it had no oil pump or no oil metering pump. He said to add some 2-cycle oil to the gas. Is that what premixing is? where do you put the motor oil if there is no pump? i don't really understand this. I'm not even sure if my questions make sense.

Stanello

iTrader: (1)

The oil metering pump is a seperate pump from the oil pump. It injects oil into the combustion area for added lubrication, etc. If the metering pump is removed, addidng 2-cycle oil (TCW-3) to the gas (premixing) at about a 1oz to 1gal ratio will give the same effect.

ultrataco

iTrader: (2)

I assume he meant the omp, because I don't see how the car could run without an oil pump or how you would add oil. Is there any reason he would remove the oil pump?

"If the metering pump is removed, addidng 2-cycle oil (TCW-3) to the gas (premixing) at about a 1oz to 1gal ratio will give the same effect."

are you saying the lack of an omp the reason for using a premix? no omp=premix and omp=no premix, right?

why premix with 2-stroke instead of normal oil like in the engine?

and what's the point of removing the omp?

Aaron Cake

iTrader: (1)

Assuming that the car has not been hacked in some way (ie. metering nozzle holes in block and intake still in tact) then it is not hard to put the system back on.

You need to remove the metering oil pump blockoff plate, bolt the metering pump back on, connected it to the throttle body with the rod, run the lines and install the nozzles.

All the parts are commonly available used. The Factory Service Manual (see FAQ) has complete procedures on removal/installation as well as the required gaskets/washers.

J-Rat

iTrader: (2)

There has been evidence that premixing is better for your motor.

TitosToy

white87fc already explained it:

in other words, without proper lubrication the engine will seize and that's an expensive fix. so yes - no omp=premix. have you ever rub 2 pieces of metal together? imagine how the seals and housings would be when the motor's turning 1k-6k rpms without oil.

i think its because 2cycle oil mixes better with gas and burns alot cleaner than conventional engine oil

cool_as_crap

better THAN an omp or in addition to?

ultrataco

iTrader: (2)

and why remove the omp? that seems pointless to me.

Aaron Cake

iTrader: (1)

You share my opinion. On a street car, it seems utterly pointless when the stock metering system has been working fine for years...On a track car then things are a little different since removing the pump cuts weight (though only a tiny amount) and does make the engine slightly easier to service.

Natey

iTrader: (19)

Mine was removed for two reasons:
1. when the motor was pulled for rebuilding, the lines were toast. It was late and we wanted to get the job done, so we made a couple of plates and zip-tied that sucker.

2. 2-stroke burns cleaner than dirty motor oil. That's gotta be good.

That said, I'm doing all I can to hook that puppy back up. I just don't trust myself to remember to premix everytime.

Secondmessiah

2 stroke oil is designed to burn, and burn clean (if you know how a two-stroke works)

the OMP injects a little oil from the oil pan into the intake, which lubricates. Unfortunately, normal engine oil isnt designed to burn clean, and therefore could slightly reduce the lifespan of the engine. (this is also why we aren't supposed to put synthetic in our cars)

some people (especially people who race their seven) will disable their OMP and premix their fuel, that way the engine is lubricated more properly, and doesnt have the deposits that build up from burning engine oil. The disadvantage is that if you forget to premix, youre pretty screwed.