Hi, I'm Robby from Florida. I just purchased a bone stock 1990 RX7 convertible two days ago. Ended up registering after trolling the forums for a while.


After I got it home I started having troubles with it. I've corrected a few issues, but now I'm getting codes 26-27 from the ECU, and have it a brick wall. Both codes point to the "MOP", or maybe some kind of wiring/ecu issue.

I want to find out what ECU the car came with from the factory so I can make sure its the right one, and I also need to find out where its located.

I also would like to learn where the '"MOP" located on the engine. I'm currently using the FSM to try to diagnose the problem, but I dont understand what I'm looking for. Some pictures of it installed on the engine would be greatly appreciated.

I would have posted my troubles in the appropriate forum but I presently lack the necessary post count :/

 

mop pumps oil to lube seals. here is a pic off car. http://www.atomicrex.co.uk/downloads...5/100_3940.JPG some remove it and run premix in gas tank this throws a code on stock ecu

 

We have an archived thread in the 2nd gen section for ECU PNs: https://www.rx7club.com/2nd-gen-archive-72/ecu-part-numbers-applications-873382/

You may have one of a few problems:
1) MOP/OMP unplugged
2) MOP/OMP wiring damaged
3) MOP/OMP has failed
4) MOP/OMP failed and was replaced, but the ECU was damaged.
5) MOP/OMP has failed and ECU is damaged.

#s 4 and 5 happen often when the pump fails. Apparently resistance drops in the circuit, and ends up burning part of the ECU up.

 

I discovered the ECU has waterstains / calcium deposits on the case and curcuit boards. I'm going to try replacing the ECU first. If I still have a problem with the MOP I'm going to delete the MOP system and run premix.

Is there any reason I can't run a normal S5 N/A ECU in my vert, or do I need the vert specific ECU.
The vert uses the n353 ECU, and the hard tops run the n351 ECU

 

You can use an N351 or N353. But you should test the MOP per the FSM before plugging a new ECU in. If the MOP is the problem, you could end up frying your new ECU.

 

Thats what I had in mind. I think I saw the MOP last time I was in the enginebay. Its on the passenger side of the front of the engine near the waterpump right?

Also, is there any reason I can't seal the ECU case with neoprene (around the connector) to prevent water damage in the future?

 

The metering pump is on the passenger-side of the front cover, under the water pump housing.

You can seal the the ECU, but water damage suggests your top is leaking.

 

It is leaking, found out yesterday. Temporarly using home depot weatherstrip to seal it, and put some towels on the floor to absorb the water. I'm gonna go ahead and seal the replacement for extra insurance (simply because its a vert)