I'm getting fuel cut as soon as I'm out of a vacuum regardless of RPM...

I'm thinking a bad MAP, but would like to hear from anyone else who's experienced this type of problem

-S5 TII

 

test the pressure sensor to be sure it is sending the correct signal, you likely have the incorrect pressure sensor installed. ie if you have an n/a sensor on the car then it will register full boost at only atmospheric pressure. the pressure sensor is what tells the ECU that you have hit the boost limit which turns on the boost cut so yes, you are on the right track.

 

I have a FCD, and its the correct sensor for the car...I'm going to test it, its just been very cold and by the time I get home from work during the week theres very little daylight left

 

Pressure sensor is fine...2.0v at 3.9inHg
Grounds - cleaned
Boost leaks - checked


what else could it be?


-or anyone know a good rotary shop in SE Mass....I'm getting discouraged with this car

 

OMP failure limp mode behaves like this.

 

ok...so heres the story with my OMP...and what I was told (again, been working on imports since I was a kid..now 32...but this is my 1st rotary)

The car is an S5, the motor is an S4 block w/S5 sensors/electronics
The car is using the mechanical S4 OMP but the S5 one is plugged in and just sitting in the engine bay. The previous owner told me that as long as the ECU saw the electrical OMP plugged in it wouldn't give me a problem. He said the car was like that because theres no way to adapt the elec S5 OMP to the S4 block...

Theres no CEL so I never had any cause for concern....but I guess I'll try testing the electrical OMP per the FSM...unless theres an easier way?

 

Well sounds like my set up that i'm going to be doing tomorrow.

The question is, is the linkage hooked up so the omp is operational. If not, are you premixing? You can use a s5 omp, by switching front cover...

 

Sounds like the S5 OMP is bad, it can still throw a code to put the car in limp mode even if it's just hanging. Check your ecu for codes and probes the wires on the omp (see FSM). I had this problem on my car and I ended up getting an rtek to run premix and just get rid of the damn thing (I went threw 2 of them). Chances are the stepper motor is bad in the omp and is throwing a code and putting you in limp mode.

 

Check the FSM to see how to read the codes, I bet the ECU is throwing an OMP code. Does it work normally for the first few minutes after you start it before this behavior starts?

 

the mechanical OMP linkage is hooked up and it does work....has the newer clear tubes

also run premix every other tank for safety


I'll try pulling codes this weekend when I get a few minutes, will post up the results


thanks for the help

 

ok, so I ohm'd out the OMP...it came back within spec

pulled the codes, I got: 25, 30, 31, 32, 33, 38, 42, 51

They're all output devices, none of them are input so theres no fail-safe for them...ohm'd out the fuel pump resistor relay (code 51) for the hell of it and it checked out within spec


The car does it all the time...cold, warm, whatever.
As long as I'm very light on the throttle, the car is fine...can rev it all the way up to 7k

I'll have to try keeping an eye on the safc, maybe its throttle position related instead of boost...?

its very hard to tell

 

S5 don't have mechanical OMP.

 

Read post #6