Life without MAF - 1000 miles later

[HarryM1BYT]

Originally Posted by tonewheeldude

Interesting about the dish washer

I would still like to know exactly what the MAF is supposed to do. Lots of knowledgeable people with authoritative opinions but still no hard evidence.

Its an MG Rover vermiform appendix!

In the MAF is an extremely fine wire. A current is passed through the wire, which heats it up, whereas the air going past it cools the wire down. The faster the flow, the more it is cooled, lower lower its resistance. This feeds into the ECU, as an air flow measurement.

Air varies in density, on temperature, so the ECU also has a temperature sensor in the pipe from the intercooler (MKII).

Knowing how much air is flowing into the engine and its temperature, the engine ECU can adjust the opening period of the injectors, so as not to put too much fuel in.

Lacking the MAF input, the ECU has to make a guess at the amount of air going in, by referring to a table of what it ought to be, based on the rpm. Which is where things can go wrong, because engines are not all identical and parts suffer wear. So we get some saying their cars work normally, some produce smoke, some suffer poor performance, some poor mpg.

[Robson Rover Repair]

Or you could have a mafless remap like myself! Car drives fully from normal revs like its got a working maf to full rev range.

Just shy of 40k miles later and nothing wrong with how the car drives bar an improved dose of mpg and a saving of a maf replacement which payed for the map!

[johnnyb44]

Hi.
Im into new territory here but I've just recently had the 160 remap and was advised that my maf was out of spec. I've been running the car with the maf disconnected and the results have all been positive. The car flys along now like a scolded cat !!!and revs so freely, as before it felt quite bogged down. Its so much smoother and flexible it has become a very refined drive all round. There is no smoke thrown out the back either .With the maf disconnected i thought there would of been some drawbacks but i can't find anything. The fuel consumption this week has averaged a shade under 45 mpg which for an auto is not bad at all. It fact i usually average around 43 mpg so early indications suggest its better. After reading this thread with interest it begs the question what's the point of even having a maf fitted to these cars? Will it have any long term detrimental affect if i leave it unplugged ?
If not im leaving my car just the way it is ...Maf less. .
Many thanks.

.
johnny

[Robson Rover Repair]

The 160 map is designed around a car with a functioning maf, you will be getting peak power only between 2000 and 4000 rpm without you maf plugged in or if you have a failed maf, unlike a car that either has a correct maf within working spec or has had a mafless remap, which will allow to car to not only rev through the range correctly, but give you peak torque from a much lower section of the rev range.