Hey, my car is a 90 GXL 2+2 and I have a code for the OMP! While driving my car about every 10 mins or so my car decides to fall on its face. So, I have to turn the car off then back on to clear the code and I am good to drive for another 10 mins ! I am currently premixing my fuel because I know that the OMP is not working right. My question is, how do I rewire or trick the CPU into thinking everything is ok ... I have looked everywhere for a write up! I do not wish to replace or fix the omp, I want to remove it! SO PLEASE HELP! Thanks!

 

Heh, if you've got the chamnpagne colored car w/ red interior, we've got the same car! :P.

I've also got the exact same problem. From what I've read, the only thing to do on our s5's is to replace the OMP. Whether or not you actually hook up the oil injector lines, or just keep premixing, is up to you. But the OMP has to be wired up so the ECU sees it there.

 

If the computer says the OMP isnt working its not. The stepper motor on the side is what usually goes bad. You could probably get away with pre mixing but you'll still run into a drivability problem because the computer is going to put the car into the limp mode. You may have to look around Ebay or something. Ive heard those things are a little pricey... and you cant get something like that aftermarket.

 

Pretty much no choice but to replace it, you can always try to tear it apart and clean it and see if that's not the problem (worked for me), but chances are it's dead. And there's no known method of avoiding it at the moment.

 

Just go to the junkyard and get another... they cost like 50 bucks at the junkyard... I dont think you need a new one if you wanna keep premixing anyway...

 

Your only choice really is to replace the OMP...as far as I know, no one has come up with a way to trick the ECU yet. I heard that the S5 RTEK ECU may have this feature when it is released though. That will be HUGE for S5 owners.

Also, when your OMP goes it sometimes takes the ECU out with it, so you may want to replace the ECU at the same time. I just went through this a year or so ago.

 

you prolly want to get a new ecu with the omp, if you use a working omp with a busted ecu the new omp gets fried and if you use a bad omp with a working ecu the ecu gets fried. I went through this a year and a half ago, i almost sold the car because it made me so damn mad.

 

I have a 89 (S5 parts car). Let me know if interisted. $ 100 for the ECU and OMP shipped.

 

I was just wondering - my car still burns about 1qt/3k miles, but to be safe I'd like to run premix for a tank or two until I have the time to hook up the new OMP.

What would be a good # of quarts/gallon to use during this time period?

 

Why did mazda change that?! IF IT AINT BROKE DONT FIX IT! The only thing that I can see is that the motor wouldnt get any oil if you were engine braking. But it seems like the s4 engines last just as long as the s5's.

 

^^ why would the engine not get oil when you are engine braking?
you dont know half as much about these cars as you make yourself out to...

 

Dude what is your deal with me? What I meant by "not getting oil" is the Oil injection. I was just wondering why they went to a stepper motor instead of just keeping the rod that hooks to the throttle body. The omp uses engine oil pressure to feed the oil injectors. With the stepper motor... it can control the amount of oil going to the injectors. But with the older s4 rod type... its dependant on the position of the throttle. And it was all just a guess!!! So stop being a jerk.

 

dude... YOU stop being a jerk
even when the throttle is closed, it still gives oil
how do you think the engine idles

 

I agree... there could be a little bit of oil that is constanly being fed. But if youre at 7000 RPM and you let up off the throttle... the OMP is in the same position... closed. And thats just a guess. Does anyone know how the OMP actually works? Im not 100% sure.

 

omp works by a a little gear... that gear touches the gear that the cas uses....
so the higher rpm you go, the faster that thingy spins

 

The reason for switching to a stepper motor and moking the OMP compuer controlled is so that there is more control over the oil injection. Meaning that at idle there is less and under load the engine can get more oil reguardless of engine RPM. Consider the oil injection "mapped" similar to fuel injection.