Hi, I have a 90 TII that has bad apex seals in the rear rotor. The guy I bought it from said it was due to a bad electic oiler. He said the S4's had a manual oiler, and the S5 were electric and very costly to replace. Anyhow...

I plan on rebuilding my motor in the near future, and would like to know how to get my oil injection working properly (and reliably) again. Any ideas? Thanks!!

 

Yes the S5 has an electric oil metering pump (OMP or sometimes called MOP). If it was malfunctioning a CEL would pop up and put the car in limp (home) mode. So it sounds like the previous owner drove it knowing the OMP was not working properly and did not premix (necessary precaution when stock oil injection is not working). You can find a used electric OMP for probably around $75-$150 in the for sale section.

WARNING: Sometimes when the electric OMP goes out on the S5 it also takes out the ECU with it as well so you may want to open up the ECU and check for any burnt circuits. Even without any burnt circuits there is a chance that the ECU is still bad and putting a good OMP in with a bad ECU may cause the OMP to go bad as well. So you may want to consider replacing the OMP and ECU at the same time.

 

Good advice!

 

is there any way to test the electric OMP to see if its working properly? The car still starts, but runs on one rotor. No check engine lights or anything like that. Just runs like ****.

The car also has 142k miles on the original motor, so I think it was just time for the motor to croak. Im not 100% sure about his "bad oiler" idea.

 

If it's the original engine, it may be on it's last leg. The stock 3 peice apex seals don't last as long as the older 2 piece design. The top piece of the apex seals has a problem with flipping out of the rotor groove in a high mileage engine. Do a search for compression check and test the engine. Then go buy a factory service manuel "FSM" or Haynes manuel and check out the OMP. If the compression is bad, it's better to rebuild now before more damage occurs.

 

lol, Tvon... we will act like you didnt reply. Im not sure what you were babbling about but i already know that my engine needs rebuilt, and I know it has bad apex seals. If you would have read what i posted, I said that i think the engine died from high milage. But i would like to make sure that the OMP isnt bad so I dont ruin the rebuilt motor.

So, back to my question... How do you test to see if the electric OMP is working correctly?

Thanks

 

For future reference download the FSM here

http://www.teamfc3s.org/main/factory...ual/1989_1991/

 

ok cool, thanks a bunch!

 

I'm surprised nobody has mentioned it yet, but you could just premix block off the OMP.

 

I thought about the premixing thing... I would like to do it just so I dont have to worry about the OMP... But my car is bone stock, and in really good shape. I dont really want to change anything on the car. I am eventually going to try to make it factory mint condition. So premixing is kind of out for me.