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-   -   OMP problems (https://www.rx7club.com/3rd-generation-specific-1993-2002-16/omp-problems-1045151/)

Brianben Sep 2, 2013 09:08 AM

OMP problems
 
I know this sounds stupid but my omp isn't working under load, I just bought a new one and someone said my ecu could be messed up? I have a power fc with the commander. Idk I'm just asking other people's opinion on if just replacing the omp is the cause or if it could be the ecu... I tested the five volt wire and I'm getting that but then the reading from the ecu is different like 1.73 volts and doesn't go up under load, this is also the reason my car I think isn't boosting I have done boost leak test and found them I even replaced the twins... Witch sucked, and hav replaced the waste gate actuator like 4 times so I think it's putting it in limp mode because the voltage to the omp isn't right under load

ZoomZoom Sep 2, 2013 10:31 AM

This doesn't help you but most of us ditched the 3rd Gen OMP and went with a mechanical 2nd Gen unit.
And by most of us I mean me, as I can't speak for most of us lol.

It is a fairly common practice from what I understand. Maybe someone can chime in about your specific problem.

Sgtblue Sep 2, 2013 11:20 AM


Originally Posted by ZoomZoom (Post 11562934)
This doesn't help you but most of us ditched the 3rd Gen OMP and went with a mechanical 2nd Gen unit. ....It is a fairly common practice from what I understand.

Disagree.
First, you can't change to a "mechanic 2nd Gen unit" on the stock ECU. That would put the car into limp mode.
Second, of those who mess with the stock OMP at all, most probably delete it along with moving to a standalone. Others install something like an RA adaptor and still others, like myself, premix at a reduced rate with a working stock OMP.

To the OP: You have a PFC, so you're not in limp mode. An malfunctioning OMP would have nothing to do with how the engine runs in the short term. I'm not certain what the problem is on the OMP you have. You said it was new, but the last time I checked they were rediculously expensive. So I'm assuming that when you said you "bought a new one" you mean you installed a (new to you) "used" OMP? Maybe it was no good.

Brianben Sep 2, 2013 12:12 PM

I haven't installed it yet but yeah "used" but if it's running at the same voltage even under load, that means the motor isn't getting enough lube for the motor, it will start going into boost but then die off at about 4000 rpm because it's going into limp mode I kow it's a pfc but it's pretty much a piggyback system @sgtblue

Peruvianrx7 Sep 2, 2013 12:21 PM

Just add premix

Brianben Sep 2, 2013 12:24 PM

@ Peruvianrx7 but how do I do that with the power fc? If I take the pump out the omp plug will read 0 volts, and if it's in limp mode in high rpms it will defiantly be when it's at 0

Sgtblue Sep 2, 2013 12:31 PM


Originally Posted by Brianben (Post 11563020)
I haven't installed it yet but yeah "used" but if it's running at the same voltage even under load, that means the motor isn't getting enough lube for the motor, it will start going into boost but then die off at about 4000 rpm because it's going into limp mode I kow it's a pfc but it's pretty much a piggyback system @sgtblue

There is NO LIMP MODE WITH A PFC. If you have a PFC and the car is running poorly, it's not because it's in limp mode. Limp Mode is only with the stock (or re-flashed) ECU and means that if the pressure sensor (boost sensor) doesn't see vacuum, timing isn't advanced and fuel is cut. That means you can't boost at all. And it isn't a piggy-back either. It's a programmable standalone ECU.

Originally Posted by Brianben (Post 11563034)
@ Peruvianrx7 but how do I do that with the power fc? If I take the pump out the omp plug will read 0 volts, and if it's in limp mode in high rpms it will defiantly be when it's at 0

I also recommend you pre-mix at about 1 oz. @ gallon until you get it sorted. You pre-mix by simply adding 2 cycle oil into the gas tank. Has nothing to do with having a PFC or having the OMP in place.

Brianben Sep 2, 2013 12:50 PM

Sort of lol pfc does has a limit, not as big as a limit as a true stand alone, but you think it really could be my map sensor? I could buy one of those too lol

Brianben Sep 2, 2013 12:51 PM

Sort of lol pfc does has a limit, not as big as a limit as a true stand alone, but you think it really could be my map sensor? I could buy one of those too lol @sgtblue

Tem120 Sep 2, 2013 12:58 PM

OMP delete one less thing to break . Like stated above I've premix 1 oz per gallon and just be done with it , better lubrication overall with premix

Brianben Sep 2, 2013 01:02 PM

I had the cosmo twin turbo in my fc last, and had it set up that way I hated going to work smelling like burning oil haha, it sucked and I just don't want to run it strictly on premix

Sgtblue Sep 2, 2013 01:11 PM


Originally Posted by Brianben (Post 11563063)
Sort of lol pfc does has a limit, not as big as a limit as a true stand alone, but you think it really could be my map sensor? I could buy one of those too lol

Have no idea what you implying, but the PFC is a progammable stand-alone.
And I never suggested it was your boost sensor.

Originally Posted by Tem120 (Post 11563073)
...better lubrication overall with premix

Not necessarily.

Brianben Sep 2, 2013 01:13 PM

Yeah but if I'm not boosting would mean the map sensor isn't getting anything right?

Sgtblue Sep 2, 2013 01:25 PM

:facepalm4:

ZoomZoom Sep 2, 2013 01:36 PM

I am confused by some of these replies and talk of limp modes and other nonsense. Seems you have other problems besides oil metering and there are limits on how much the forum can help. I suggest getting the car sorted by an experienced and trusted shop that knows their way around RX7's.
Sounds like there are multiple problems in play.

Brianben Sep 13, 2013 11:03 PM

Fixed my boost problem!! Just boost leaks everywhere, but my vmop is still only reading 1.81 volts, after the tune from the shop it's been having a hard time starting on cold starts it's only been a couple of days but I'm concerned with the health of the motor, should I just run premix? My motor runs fine and still pulls hard but with the voltage not rising I don't want to go woot anymore because it might damage the motor, when tuning it, it was having an idle flux. Going up and down, and tuned that out, and said it could be a vacuum leak causing that but he tuned around it, and today I was driving it around an it just died for a second, then kick started it and ran fine no noises or funny sounds, to me it feels like a dead spot in the throttle, cuz when it did die I taped the throttle just slightly and dies, but not at operating temp. So far untill today witch was weird.


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