A friend of mine installed a new engine, all the solenoid valves new, rebuilt turbos, new actuator wastegate control, new actuator turbo pre-control, new actuator charge control, new charge relief valves, new injectors, new ignition coils, new pressure regulator, new vacuum hose(small ones), new TPS, new wiring harness, new ignition wires and his old OMP(oil metering pump).When we went for a test drive the car behaved like this: boost pressure sequence was 10-8-0. After 4 days of searching the manuals and testing the car again and again we decide to change the OMP and the car now works perfectly. I want to ask the following. Is it possible when the ECU goes on safe mode due to faulty OMP, not to show any error codes on the checker?

 

A bad omp or its wiring should give a code and limp home mode .When I refer to a bad pump I am referring to the electric parts . If it fails mechanically and does not pump oil the computor does not know .

 

If the computer as you say doesn't know, why is it cutting fuel?

 

If it is electrical the computor goes in the limp mode. If the mechanical part or the oil lines are broken there are not any sensors for that . No oil , no sensor , no code .

 

Lets assume that we have a mechanical malfunction. ECU has no error, but its cutting fuel.
Why is that happening, since it hasn't been into limp mode?

 

If the ECU is actually cutting fuel, it should store a trouble code. What kind of problem are you having?

 

Stupid question does you check engine light actually work and what did you use to check the code. If you jumped the diagnostic connector, you might have jump the wrong two wires.

 

We used an OEM Mazda checker and please read the thread carefully. All the symptoms are in my 1st post.