barriesheene Posted November 9, 2011 Share Posted November 9, 2011 Apart from all the other issues that my Rangie is experiencing at the mo I do have one big concern. It's down on power. I've been told that this is probably down to the mass airflow sensor. It would make sense as I removed a blowback protection flap and she ran well for a few miles then returned to lack of power, ( as if the airflow sensor was resetting it back to a **** setting ). My big concern is the white smoke !!!!!! It doesnt do it all the time but I'll be driving along and suddenly plumes of smoke out the back !!! This then clears and no smoke ??????? Few more miles then smoke again ????? No signs of normal head gasket problems just a lack of power. I'm going to put the power down to the airflow sensor but what about the smoke ??????? Quote Link to comment Share on other sites More sharing options...
discomikey Posted November 9, 2011 Share Posted November 9, 2011 could it be your coolant temp sensor? or something in this area? when a vehicle reads cold the fuelling is increased which can result in fuel vapours (the smoke) also running rich will put your power down (im assuming its a v8) if the sensor is faulty it will show these signs, sometimes without the guage reading wrong but the guage is usually a sign also if the connection is loose (this would explain the random smoke. i.e. even more fuel put in every now and then as it thinks it gets even colder. then again i could be wrong, just my 2p Quote Link to comment Share on other sites More sharing options...
barriesheene Posted November 9, 2011 Author Share Posted November 9, 2011 Hmmmmmmm She does smell rich ?????? Liking the sound of this Mikey. It's a 4.6 V8 so I'm just thinking the worst, slipped liners, porous block etc Quote Link to comment Share on other sites More sharing options...
discomikey Posted November 9, 2011 Share Posted November 9, 2011 hope for your sake im right as its a cheap fix. Quote Link to comment Share on other sites More sharing options...
SteveRK Posted November 9, 2011 Share Posted November 9, 2011 coolant and or fuel sensors wont have any affect whenever the pedal is on the floor. At 3/4 or more throttle the closed loop fuelling goes open loop fixed fuelling. It depends what you mean by down on power? absolutely gutless or not quite giving the push that you would expect? So, key question is if you floor the pedal and keep it floored does it pull as you would expect? Quote Link to comment Share on other sites More sharing options...
barriesheene Posted November 11, 2011 Author Share Posted November 11, 2011 Steve you've got me excited . If you floor it it's fine. It hitches up its skirt and flies but at anything else it just doesnt want to know. I've replaced the fuel pump thinking it was that, but no change. Quote Link to comment Share on other sites More sharing options...
discomikey Posted November 11, 2011 Share Posted November 11, 2011 when you have a look be sure to come back and report cos im interested to see if i was right or not Quote Link to comment Share on other sites More sharing options...
Range Rover Blues Posted November 12, 2011 Share Posted November 12, 2011 I can't see what year it is, but here's a few tips. If it's got lambdas then it will only listen to the MAF sensor for a few seconds 'till it sets a base idle against the lambdas, it takes a few seconds IIRC. After that it runs closed loop virtualy all the time. If it does have lambdas, it should start with the MADF disconnected, mine does though ti runs rough. The MAF had packed up and I didn't know 'till I'd been towed home when it wouldn't start, had I unplugged it I'd have got home. On an open loop system it might not start at all without the MAF and will run rough as the proverbial if it does. But, if you think it ran better before it "learned" the faulty sensor then unplug the ECU or disconnect the battery, it will reset the ECU. Quote Link to comment Share on other sites More sharing options...
SteveRK Posted November 12, 2011 Share Posted November 12, 2011 If full throttle is fine then i'd do as Mikey suggests and start investigating the various sensors and other parts of the fuel injection systems Quote Link to comment Share on other sites More sharing options...
barriesheene Posted November 12, 2011 Author Share Posted November 12, 2011 Thanks guys I'll let you know how I get on. Quote Link to comment Share on other sites More sharing options...
Range Rover Blues Posted November 12, 2011 Share Posted November 12, 2011 The Haynes manual has most of the info you need to check the EFi system with a multi meter, it's in the suppliment. Quote Link to comment Share on other sites More sharing options...
barriesheene Posted November 15, 2011 Author Share Posted November 15, 2011 HAYNES MANUAL !!!!!!!!!! ??????????? I wish Sorry guys its a p38 so no haynes Quote Link to comment Share on other sites More sharing options...
elbekko Posted November 16, 2011 Share Posted November 16, 2011 Check the lambdas, they're support to stop adjusting at WOT. Quote Link to comment Share on other sites More sharing options...
barriesheene Posted December 15, 2011 Author Share Posted December 15, 2011 Update guys. Just got it back on the road after changing the heater matrix for the 3rd time in three months !, ( dont ask ). There's been a development ???? Running spot on now except.............. Shes idling at 2000 rpm when not in gear ????? Any ideas? They have to be related. Running poo but idling ok, then running sweet but idleing like its running on caffeine I'm tempted to leave it as is but 2000 rpm in gear at trafic lights cant be doing my torque converter much good Quote Link to comment Share on other sites More sharing options...
alfmech Posted December 15, 2011 Share Posted December 15, 2011 i might be a little backwards on this but have you checked throttle postion sensor and looked for air leaks, my old 3.9 used rev like a sod if there was and air leak, probably dosnt apply but its a thought Quote Link to comment Share on other sites More sharing options...
discomikey Posted December 15, 2011 Share Posted December 15, 2011 unless oil can wear, your tourque converter will be fine, it works by throwung oil round and using centrifugal force with cleverly desinged fins to direct flow the flow depending on how hard it is (ie. how fast) will give more and more resistiance against the fins, until it reaches a certian RPM, and the two halves of the torque converter spin at 1:1, this is called torque convertor lock up. Quote Link to comment Share on other sites More sharing options...
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