Nistune Forums

was driving today, and nistune just went mad. Lost all my power and the car started jumping way up the load scale.
The first pic is the with the key on, the second is the car started but bogging with no power and no idle (not even drivable).
tried switching my Z maf back to my stock sr maf and no luck, checked grounds, everything looks good. Any ideas?

MAF is reading 2.8volts, that's the problem i'd imagine.

Whether its the unit itself, the wiring, or the ECU, something is not happy with the MAF for it to be that high at that rpm.

Yup, as above, it's reading 0.78v in the first pic and 2.8v in the 2nd pic, so the MAF is seeing a larger airflow than there actually is which it determines as high load on the engine. It's probably bogging down due to the ECU injecting more fuel than it should be due to thinking there is more air entering than there actually is.

Can the car be driven at all? On cruise it will enter closed loop and the ECU will rely on the lambda to keep fueling constant 1 lambda. What readings do you get from the MAF when you change it to your stock one?

You can also see in the 2nd pic that load is 152 (off the scale) compared to the 19 in the first pic and the injector time has increased from 3ms to over 12ms, it will be getting flooded due to false readings from the MAF.

AFM voltage is obviously a critical parameter. But this is particularly so at low RPM. You'll usually see around 1.0 to 1.1V at idle from a Z32 AFM. This only has to increase a small amount (1.5V will totally throw things out) and it'll cause the ECU to access cells about halfway across the fule table instead of sticking to the left hand column. Which will make things rich enough to stall the engine.

PL

I had a friend weld my i/c pipe, just discovered a hole in it.
All my air was leaking out, works perfect now after the fix.

That'd be "ex-friend"!

PL