I found online the basics of an ECM (not rover specific). It's a PROM chip with stored values in tables for fuel mixtures & timing using the parameters
determined from sensors. 5 main modes:
(1)start
(2)run cold
(3.a) run hot open loop (default settings using air flow)
(3.b) run hot closed loop (MAF + O2 sensors when warmed).
All of this to make a near perfect air fuel mixture.

(4)limphome
(5) backup
when sensors are bad.

sometimes your car can be in limphome mode without realizing it, it will idle rougher or cause starting problems.
Ex. a bad thermostat valve can trigger limphome if the ECM senses the engine is too warm or too cold after several cycles.

 

Removed my air box and installed the Spectre from AutoZone. My 17 year old has been driving the truck this week, got 17mpg. 97 D1, 173K

 

I did this...and it seems like my MAF is whistling like crazy at part throttle

 

Old thread bump!! I just ordered this beast:


It's essentially the same as the Spectre, but I get the cool kid points of K&N for only $0.16 extra. Hate on haters.

Also, I've recently been switching over to non-ethanol gas. The first fill up was with a half tank of E10 already in there, so I essentially made my own E5 mix. I filled up again with a half tank of E5 still in it, so now I'm at E2.5. Eventually, I'll make it all the way to E0.00000whatever. I only pass by the place every so often, so I gas up when I do. I had been averaging about 9.5mpg. I got a lot of weight. No judging. With the E5, I averaged 10.9mpg. No reports on the E2.5 yet, but if the trend continues I'll gain at least an extra 2mpg, if not more. Add in the rice filter, and I may hit mid teens(woohoo). Anyhow, I'll report back any changes. BTW, she runs much better on non-ethanol. Smooth and silent idle, and overall better engine manners. I highly recommend it, if you have it nearby.

 

Ok, damit, I was waiting for someone like you to do this! Now I'm in! Going to get one today.

 

Got this installed today and located some non eth gas. Gonna fill up today with 91 octane non eth. fuel. First impression w new filter, def can feel the better responsiveness. This is perfect when using the magnaflow exhaust. Makes sense: less restrictive exhaust coupled with less restrictive airflow.

My only fear, nothing is attaching this filter but the clamp to MAF. It is being supported vertically sitting atop of the shock tower. Got my air box in back just in case.

 

Yeah, I just used some redneck ingenuity and zip-tied it around some holes in the inner fender. The IAT sensor is zip-tied to a brake line near the ABS modulator. No problems so far, and my long term fuel trim has been within a couple points of zero. I'm gonna try and fab up a thin sheet of tin or something to at least cover the bottom of it for protection against any water splashing up.

 

Holy crap! I bought a tank of 91 octane 100% gasoline today for first time and with my cone filter it is noticeably different. Throttle response better. Low end torque better. Even my high idle has calmed down some. Now hovering just over 1000.

Is it getting better fuel economy? Hell no! I can't keep my foot out of it now.

Next to open up the exhaust just a tad more.

 

Hmmm i need better gas milage on my 03 Disco II any success? Not to mention, both my airbox and airbox lid are both broken at the clasps and one attacking to MAF it has to be replaced (not MAF) just clasps too from expensive airbox

 

ok picked it up and installed it in less than 8 minutes... here is a pic... my 03 Discovery II .. and I have to admit it was instantly running better... I have been suspecting my rough idling could have something to do with my intake... mostly maybe the filter I was using puralator, or just something... I thought maybe it was because both the box and lid both have cracked clips... letting air in all over the place... anyway.. a new box and lid are not cheap even used.. so for 25 bucks I thought Id try this... and hm... engine has smoothed out and silky acceleration... hmmm.... wanna see?? btw the color depicts the part number... the part number I saw here earlier something like 8136 or so... is the blue one... the 8132 is red and there is a black one I saw also... no white was there at my auto zone... I have some blue 8mm kings borne wires to go on when I can get enough initiative to install them and will match this nicely... red would probably matched my red body better but hey I like blue lol BTW... Im going to cut a notch into the lower box that allows this to sit into that box... my box is pro ken anyway so no loss.. but it will help incase some water got up there.... so far Ive never had water get that high and I don't drive in mud... eewwww ... lol