so yesterday i was driving down teh freeway and my check engine light came on, i didnt notice anything till i went to give it a little more gas and all of a sudden rpms drop to about 2k and the engine is misfiring like crazy. now i have heard this could be the OMP or (MOP)?? but if i give it a small amount of throttle then it will run fne. i turned it off and turned it back on and it was fine??? i heard you could swap in s4 OMP. does anyone have a picture of where they are located?

 

its located at the bottom of the front cover on the passenger side. you can use a mechanical s4 omp but you still need to have a good working s5 one hooked up so the ecu doesn't go into limp mode. you probably would also need the s4 front cover and tb linkage.

 

si im kinda fucked right?? cause i arent s5 OMP like 1500$, what exactly does the OMP do, does it actually just measure the amount of oil or does it control how much oil is being pumpd through my injectors... and is driving it gonna damage my motor??

 

If you think its the MOP giving out start throwing some 2 stroke oil in the gas a preventative measure incase you are right. Assuming your car is a 91 like your user name implies yes a bad MOP could cause limp mode. is your car a 5-speed? If so I would worry about why the rpms would drop without the speed dropping considerably. Try pulling the codes before you start wanting to throw money at potential problems, its a RX7 everything is a potential problem.

 

+1

 

yes my car is a 91 and it is a 5spd, now te RPMs drop much quicker than my speed does

 

with the car still in gear?

 

Check codes, and let us know. There are plenty of people selling used omps. I don't think I have anymore laying around, but you can find them cheap. I sell off working omps for $60. But check the classifieds if the code is there.

 

You'll want to find an S5 ECU also if it turns out to be a bad OMP. 1/2 the time it's goes bad, it will take the ECU with it.

 

im having problems finding the OMP... can someone post a pic please

 

If you dont want to bother with the OMP you can run premix.

OR

Fix it:

Check the ECU its probaly burned out. if you pull the pass rug up you should smell burn(i did)

 

If you run pre mix, that takes care of the oil injection, but will not cure the problem. Digital Turning makes a chip that eliminates the OMP fault code and OMP itself, so the engine will run normal again. Google Digital Tuning.

http://www.pocketlogger.com/?pid=rte...age=1&ecu=S5NA

 

well my ecu has no burning smell at all. and the car doesnt go into limp mode till about 15 minutes of driving... it doesnt matter if its just ideling or being drivin hard it always go's into limp mode after about 15 min of running.

 

Check the OMP check the resistance with the fms and with this:

*the omp dosent always short out the ECU but if you havent cracked it open I would. Its worth the time to check. on my car, The perevious owner put in a BRAND new OMP i have the recept and a used ecu, only to fry both.

 

i dont understand something... if my ecu wad fried how would my var run at all????? also will there be any long term dfamage by driving my car with a messed up OMP???

 

For one thing no oil means the seals arent being lubed. That mean your seals will end up being toast. Id Say about 50Miles ( i read from another post) untill you start with permanent damage. Id run 150 or 200:1 premix if you will be driving just to be safe.

The ECU is the controll center of the car. It controls everything from boost to the MOP. The CPU just hold information like the radio station and time.

The ECU is set up just like a computer (DUH). It has regins that controll different spots just like a computer if the MOP shorted out it thus taking the ECU its connected to out. What happens is that the resistance is too great for the ecu to handle and burns out. The one that will go out( the OMP or ECU) depends on how or better yet if the ECU is burned yet if not (like your having) its going into limp mode before the ECU over loads. This isant something to take lightly. This can and will lead to perminate engine damage if this is the problem. here is some pictures of what im talking about:

http://i446.photobucket.com/albums/q...IMG_0015-1.jpg

http://i446.photobucket.com/albums/q...IMG_0014-1.jpg

This is my ECU. As you can see the part that controls the MOP is fried. My car idled fine, drove up to 30MPH fine but bogged bucked and and back firing.

look into it if its not this(thats why you test it first) and if it needs replacement replace it or rebuilt it. If im missing anything or miss-informing someone will correct me if im wrong.

 

uhhh i know this is a different direction BUT are your coils good? causes similar issues if you have a bad leading or trailing and do you burn gas like crazy and have horrible acceleration?

 

What causes the ecu to fail isn't too much resistance but too low a resistance. This cause a high current draw through the low current devices in the ecu.

My friend had his omp fail and it had too low a resistance on two of the 4 pin pairs.
This particular failure usually doesn't harm the ecu because what the ecu does is when it see that error condition it goes into limp mode and uses the smallest amount of omp injection and doesn't attempt to use the high range of the omp that has too low of impedence.

 

I'll be the third or fouth to ask, did you ever pull the codes to see what the problem might be?

 

alright i just pulled the codes and i got #13...preasure sensor-intake manifold. and i got 27 wich is OMP...

 

i was hopin it was much less serious.... sorry man. might be able to find a used one reasonably

 

yeah i dont think that my motor will blow cause i have already drivin like 100 somehing miles and it still runs fine. its just that after driving for a while the car fallls into limp mode. then i turn it off and turn it back on and im doin ok for another 15 min... but hopefully nothein too bad happens otherwise i might just have to buy a trbo II

 

The limp mode is not a minor annoyance-it is a signal for a problem you WILL deal with and probably soon.

Keep this up and you will have an ECU that smells bad and looks just like Ryan123's pictures.

Ask me how I know.

 

well **** idk what im gonna do. i have to drive so i can get to work and stuff. how much would an s4 omp be?? and is it hard to install the rtek yourself?? i know it depends on experience but is the rtek just plug in or do you have to wire it and soder it??

 

You have an S5 you cant just replace the MOP and be done. As stated above theres alot more to do then just an easy swap. Heres some things to look at:
https://www.rx7club.com/2nd-generation-specific-1986-1992-17/s4-mechanical-omp-onto-s5-tii-839164/

Run premix like i said earlyer. Id run 200:1 just to be safe. I used 2 stroke oil in mine so it would run a little smoother(so i was told). Also 100miles thats alot to gamble with. Plus with the Rtek you still need to run premix.. so matter what you need to add oil weather its by hand or via the OMP. But you cant do anything untill the ecu is know fried or fine. As stated in the thread above noones sure if the rtek will work on a burned ecu.