Light misfire and poor fuel consumption on 2.8 ACK engine
Can anyone help out with a fairly complex problem I've got with my 97 2.8.
It had 3 problems, the first was on initial cold start, the engine revs flew up when I touched the accelerator, tried to take off gently, engine stalled with a strong smell of petrol. There's a light misfire at low revs when pulling gently in a high gear, and recently, the fuel consumption has dropped from 30mpg, to nearer 20. It's running a free flow replacement panel air filter, new 200 cpi cats and a free flow exhaust, otherwise standard.
VAG-COM showed 2 errors, maximum fuelling limits exceeded, and no live feed to either lambda sensor. As a test, I replaced the sensor on bank 2, and with it the other one came back to life, and both are switching within operating limits. I've had it gas tested and it's passing all tests well within limits. Changing the sensor cured some of the misfire, but nothing else.
I replaced the coolant temperature sensor, which has virtually cured the cold start problem, but should it cold idle at 1150? The accelerator when cold, is still more sensitive, but the misfire has eased a bit more.
I'm not certain the air mass meter throws an error on this ECU, but I think the coil packs do, and they are fine.
What values should I get across the pins of the air mass meter ? and what other bits can I check ?
At no time has the engine management warning light come on, and all the wiring and fuses are fine.