Hi all,

My disco I had some idling problems and incredible fuel consumption.
After reading on the forums I decided to test MAf sensor and yesterday I disconnected it.

I felt the difference as soon as I start driving it. Its much smooth and responsive with MAf disconnected. I pushed it to 4000+ Rpms and have not experienced any power loss , its running smoother then ever.


Also idling problem is almost resolved its far better than before. It used to be going up and down between 1300 to almost 0, now it does it only time to time and revs are between 600-1000.



So by these results I can safely assume that my MAf is malfunctioning right? I'll try to clean it but is there any obvious reason not to run the car with MAF disconnected?


Thanks,
VCO

 

ECM won't be able to make things run on days when conditions are far different (heat, altitude, barometric pressure, etc.) - your ECM was probably using last value recorded by MAF or a default value, so if conditions change this would not run as well. It can be easily cleaned, use a spray cleaner rated for mass air flow sensors and throttle body, etc. Also clean the throttle body inside, and fine lubricant to linkage. Very important linkage not bind. See attached pages from RAVE, you can download your own copy. In typical Rover-speak, this is the hot wire MAF sensor.

A new MAF for a 97 Disco is $1500 from Rock Auto, they can also be rebuilt for less than half that, there may be swaps, and one day while I was walking the salvage yard I found one on a donor vehicle for $25, it is on the future spares shelf. And our dismantlers could be a source.

You could also have IACV issues, vac leak, etc. And if MAF is dirty, how about a new air filter?

 

Thanks for the detailed reply. heat, altitude, barometric pressure will not change much so I can save $1500

I'll try to clean it ASAP , I checked some stores but couldn't find anything for MAF but I found brake cleaners. Some people mentioned that brake/caliper cleaners are also fine for this procedure.


I was just about to ask how to clean T-body than found the thread woth the pictures and explanation. T-body cleaning has been added to the maintenance list.

Ps:new paper air filter installed 1 month ago ( when I bought the car) , but I saw some K&N stickers inside so MAf problem could be related to K&N filter and over oiling.

 

You should be able to find throttle body cleaner, may work better than brake cleaner in this application. Good catch on the oil rag air filter.

 

sounds like the MAF is busted.
were there any codes on (i assume there were...) that were MAF related?


sounds like its time to ditch the factory engine management

 

sounds like its time to ditch the factory engine management

And replace it with what?

 

anything really...

my personal preference (after many many successful installs - we just finished up a 92 syncro vw passat with a 20v turbo motor this weekend actually... took just under 2 days from start to finish) is megasquirt.

its the first thing im gonna do if/when i have a similar issue with my truck


dont mean to derail the thread though!

 

Depends on where you are at. An MS install wouldnt pass muster with the smog ***** here in CA on an OBD2 car. You might stand a chance if you were to swap it into a distributor truck and managed to utilize the stock sensors and ECU to house the MS install. As long as it passes visual and you have it tuned well enough to pass the sniffer test it would probably manage to squeak by..

 

I looked at the MS site and did not see anything about LR Discoveries. They do have one for 8 cylinders, but I did not look any further.

 

easy enough with a plug and play harness...

weve done this before on other MS'd cars. as long as the engine setup is sooo wild that the factory ecu cant handle at least running it through a smog check as a worst case.

otherwise, another easier option if you dont have to have the ecu actually scanned, is to tune it to pass smog and keep the cat in. everything can look stock enough under the hood