So I've got my engine out and just ordered a block off kit for the omp but realy realy dont want to leave it dangling in the engine bay to stay out of limp mode. Reading up on what signal the pcm needs I found that it matches the voltage range of the full range TPS signal. Just a verying voltage from 0.8-4.5v depending on where the stepper motor is. The motor is commanded up and down based on rpm from what I understand. When the tps goes up, usually rpm will follow...

My idea is to just jumper the wire at the pcm from the full range tps to the omp. My question is does anyone know the timeframe that it takes to set the code for omp and go into limp mode? If it is a fairly large time frame like multiple seconds I think it will work. If it sets instantly if the signal is even a little bit off this will not work. Anyone deal with limp mode on their car lately to know roughly how easily it is triggered?

 

When it is the OMP triggering the limp, it takes all between 3sec and 5 minutes for me.

When the ECU is fried, it is instant :P

 

cool, I think I will try it then. If it works it will be much cheaper than getting an Rtek

 

try it, but i don't think it'll work.

 

If your going to by pass the MOP/OMP (everyone calls it a different thing) I would just be safe and also get the Rtek. Nothing wrong with trying to protect your engine bro. But let us know how that works out for u.

 

I dont get what your saying, the only reason to get an rtek on an s5 n/a is to remove the omp. what would be the "unsafe" side of not getting the rtek

 

As far I've seen, no one has ever removed the OMP from an S5 without installing the Rtek. they usually block it off, install rtek or just install the S4 OMP as that one won't fry your EGI when it goes out. I haven't done it personally yet, as I'd rather just keep OMP not have to worry about pre-mixing at every fill up.

 

Burning up your ECU.

 

Attempting to accelerate in front of a semi and the car suddenly going into limp mode. Basically the same as running it as-is. But you'll never know if you fixed the problem.


Unfortunately this is all the info the fsm gives about the omp monitoring system.

You'd need to log these 4 inputs to the ecu while driving and synch them up with the throttle position sensor and engine speed. Then create an inexpensive method to condition the signal so it matches the parameters needed at the ecu. I'm all for the scientific method, but the rtek is just way easier.

 

Not to mention all the other added adjustable capabilities and features/benefits that running Rtek 2.1 brings with it, even on a S5 n/a besides the previously mentioned MOP removal;

adjustable fuel & spark maps
injector presets (handy even for high powered n/a engines)
secondary injector staging RPM
6-port staging RPM
VDI staging RPM
increase rev limiter to 9200 RPM
disable temperature compensation of timing
disable AWS
adjustable RPM activated output
data logging
checking diagnostic codes

 

those 4 wires are actually the outputs to the stepper motor in the omp, the only thing the ecu uses to know its working is the 3 wire potentiometer mounted on the side of the pump. its a 5v, ground, and signal wire. it bases its operation on rpm from what I have found. the only circuit you need to fool is the single signal wire, nobody has done it because you cant simply put a resistor in the circuit or something. It has to be a changing resistance, that resistance matches perfectly to the full range tps meaning the return voltage should be close to what the ecu is looking for but will not be correct at all times.
As long as it is the right signal some of the time, I think it will keep it out of limp mode... will see next week once the engine is in and I play with the wiring.
I dont actually have a problem with my pump, I would just rather premix for more even lubrication.

 

,, more to it than at first glance....also does resistance checks of the motor poles to be sure there is no short or open circuit .. at it is rpm and load based mapping , so not entirely what is happening at the wide range tps

also the sender at the pump runs at half the scale the wide range tps does .....

dont think your going to get it with just a variable tps signal
.. methinks a gizmo something that constantly varies the feedback signal up and down the range may be enough to keep that flag happy

 

If you want to run pre-pix, why not make things simpler for yourself? Especially if there is nothing wrong with your OMP and lines. Keep the OMP in place and just add 1/4oz to 1/2oz per gallon of a good rotary premix oil like Idemitsu. That way you have doubled your insurance.