zmame

Hello again,

Been battling with my rx7 again. Pulled it out of storage now i got it throwing codes for the OMP and going into limp mode.

Since I probably wont sell the car is there a way to disconnect the OMP without physically taking it out and running pre-mix.

I found 1 guide, but it just showed removing and deleting i was kinda hoping i could disconnect the electrical connector and run pre-mix. Also get it to go out of limp mode too.

its a 1991 rx7 13b na

thanks in advanced,
Nick Steele

Bwek

iTrader: (4)

if its an S5 it won't leave limp mode until it sees a working OMP when I went premix I physically removed it from the block and zip tied it out of the way but still connected to the ecu

sctRota

iTrader: (2)

I may have an OMP laying around my shop as I certainly never depend on the electric ones. Shoot me an offer and you can pick her up. Or you go for an rtek that correct me if I am wrong, allows you to remove it without going into limp mode.

misterstyx69

iTrader: (142)

Ya..hey Nick..how's it goin?
the Rtek will allow you to take the OMP out,But if you are selling the car it is just as well to get a replacement used operating Omp and slap it back in.

rx7racerca

iTrader: (1)

On S5s, iirc, it's more often an ECU failure that triggers limp mode - again, iirc, the ecu can be damaged by corroded contacts on the front turn signals - check your front signals, are they water tight, and see if the sockets or connectors are corroded. If the ecu is damaged, rtek or new(used) ecu will be the fix, not an OMP.

zmame

misterstyx69:

I have been doing well! working at different garage in CP now. Gave up the ford game.

I plan on keeping the car I have more into then it will ever be worth at this point and I enjoy driving it on days like today.


You may be onto somthing there.. I checked the front signals are good, but I am getting some water in the rear lenses. Also my vert top wont go back up just down.
I had problems with it on start up too that im thinking are computer related.

Some times you start it, it will rev up like it suppose to (3k 1.5k then idle at 700rpm) and wont stall. Then other times i start it I have to keep my foot on it till it's at operating temp.

Also the OMP was replaced in 2005 and has fewer then 5,000 miles on it.
I don't know if it was new or used though.

Ill pull out the ECU after work and look for any obvious signs of corrosion.

Also it use to smoke (burn oil) on start up dosen't do that anymore so it tells me the OMP is not working I haven't drove it yet so I don't damage it.

rx7racerca

iTrader: (1)

Here's a couple links related to electronic MOP/OMP failures - gist is, grounding problems can cause failure of the OMP, and in turn cause failure of the ECU because the shorted OMP will then ground back through the ECU, frying those circuits.

Second page of this thread has photo of damaged ECU and run down of diagnostics:
https://www.rx7club.com/2nd-generati...-710938/page2/

More on OMP problems/solutions: https://www.rx7club.com/2nd-generati...-turbo-937249/

zmame

Cool thanks for the info.. by the looks of the first one you could trick the computer with a series of resistors of the same value.. don't know if anyone has tried it or not. I'm going to pull the ECU out today, open it up and see if there is a burnt resistor. If so ill fix the ECU my self and save some cash.

ill check the resistances of the OMP too and go from there.

zmame

So i pulled the ECU out and opened it up and the resistor is not burnt actually the and it's not open in circuit. It was actually replaced in 05 with the OMP that is in it now. I'm having a hard time finding a new one also seems to be few used ones as well.

Any suggestions where to get a new one?