Fellas:

I've got a question for you all relating to the check engine codes for the metering oil pump (27) and the intake manifold pressure sensor (13):

I'm getting these two codes at the same time and I want to figure out if one is causing the other. Here's the scenario - after about 10+ minutes of driving my check engine light will come on and the car will stumble badly if you try to go over 3000 rpms or get into the boost. If I shut off the motor and restart it, everything is fine. When I pull the engine codes it always gives me 13 and 27; I've cleared the codes/reset the ECU and driven it again and it does the same thing.

I did some simple stuff like checking the grounds (OK) and the volts on the pressure sensor (OK) and now I'm wondering if the MOP's sensor/connector is shorting out and making the ECU put the car in the "limp home" mode... which is triggering code 13 when it limits the RPMs & boost?

Does this make any sense? It would be wierd to get two unrelated problems at the exact same time, and when I restart the car it runs just fine. My mechanic is in the process of checking out the MOP and its connection to the ECU now but does anyone think the two codes are related? The manual doesn't say anything about this.

Thanks in advance for your thoughts.

 

What you are describing is typical when the omp goes bad. The computer has a feed back from the omp and ones it senses the omp is bad the car will be undriveable. If you keep on driving the car the engine light will stay on. You can always change your map sensor first since its easy to change and a lot cheaper. I think Mazda wants like $1000 for the omp. I changed one on my friends 89 TII, but i had a used one. I have a used omp if your interested. I dont think the codes are related. But if you map sensor is bad and you hit boost yes it will drive pretty bad since i think the fail safe setting for the map sensor is atmospheric. PM me if you want the omp.

 

omp=$1400 from dealer