The V8 Owners Forum -

hi again guys....ive fitted a 3.5 into my rangie and retained the 3.9 intake and maf also the 3.9 ecu would this explain the constant sooty pipe and its hard to rev it past 4000 ???? ive tried to turn the screw on the maf to alter fueling but its no better. I thought it would of gone into self-learn off the O2 sensors and re-ajusted fueling to suit but it has'nt

btw...clean idle, new air filter.....cheers in advance

21 views help me here guys

Adjusting the MAF won't help, that's just for idle.

There are tuning resistors for that ECU, but I am not familiar with them........

CHris.

Could be in limp home mode, check all the sensors are working properly, check all connections, reset the ecu by disconnecting the power (er and reconnecting after). Get the ECU on a diagnostic if that does not work. A 3.9 EFI shouldn't be too far out especially with Lambdas.
Mike